The identification of the probable cause of equine grass sickness (EGS) is a “game changer” in understanding of the disease – and an important step towards reducing deaths.

Experts believe they have found the neurotoxin responsible for causing EGS, which has been elusive for over 100 years. Research involving The Royal (Dick) School of Veterinary Studies’ Equine Hospital, published in the British Equine Veterinary Association’s (BEVA) Equine Veterinary Journal (EVJ), pinpoints a toxin with similar actions to snake venom toxins, produced by microorganisms in pasture.

The equine hospital’s Professor Bruce McGorum said: “Identifying a probable cause of equine grass sickness represents a significant breakthrough. We hope this discovery will lead to novel treatments and improved diagnostics for this devastating condition. We are very grateful for the generous support from horse owners, veterinary surgeons, scientists, charities and funding bodies.

“Further work is under way to determine the source of this neurotoxin; it is likely to be produced by a microbe such as a bacterium or fungus that grows on grass during cold and dry weather, which typically occurs before cases of the disease are identified.”

Grass sickness is a frequently fatal condition that causes degenerative changes to the central and autonomic (involuntary) nervous systems.

For this study, the researchers considered damage to muscle tissue in affected horses and found “major abnormalities” in their neuromuscular junctions; sites of communication between nerves and muscles crucial for muscle function.

These abnormalities are believed to represent damage caused by a type of neurotoxic enzyme, phospholipase A2. The toxin is in some snakes’ venom; it is possible drugs in development for treating people paralysed by snakebite could help horses with EGS.

The equine hospital’s Prof Scott Pirie said: “This work has clearly demonstrated the value of considering disease pathology, even subtle structural changes only visible at extremely high magnification, in the quest to identify the causes of disease, particularly those attributable to the action of toxins.

“The discovery of this distinct signature of toxin activity is a major game-changer in our understanding of this devastating disease.”

The study was carried out with Newcastle University, Istituto Zooprofilattico Sperimentale delle Venezie, and the University of Padova. It was funded by the Royal College of Veterinary Surgeons’ charitable trust and the Moredun Foundation Equine Grass Sickness Fund.

Incredibly proud

“EVJ is incredibly proud to play a small part in getting this information to vets and horse owners,” said EVJ editor Professor Celia Marr. “As an equine clinician, I know this is a really important step towards addressing high losses associated with EGS.”

BEVA’s veterinary projects officer Lucy Grieve said dealing with grass sickness can be “horribly distressing” for vets.

“And it is hugely traumatic for the owner to know the likely outcome of this devastating disease,” she told H&H.

“Whilst we are some way off having means of prevention and treatment to save horses from this condition, this exciting work is an enormous leap in the right direction.

“To think that one day grass sickness could be a thing of the past is very exciting. As, of course, is the wider benefits of the work, the potential impact of which may be far-reaching across veterinary and human medicine.”

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A late Clydesdale who became an ambassador for grass sickness research and gained international fans is being remembered with an online charity show raising money to help fight the disease.

Aberdeenshire-based Lorraine Saunders’ Clydesdale gelding Mitchelhill Scott (Scottie) became unwell in January 2016, and after a referral to an equine hospital he was eventually diagnosed with grass sickness. When Scottie, who was 18 and had been with Lorraine since he was four, did not show signs of improvement it was suggested that he should be put down.

“It took some time to agree that it was grass sickness, it was January, and he was older, so he didn’t fit with the usual risk factors,” Lorraine told H&H.

“I remember arriving at the hospital to say goodbye, and Scottie heard me and whinnied. The vets said that was the most they’d heard from him. After not eating anything since he first became unwell, he then took a mint, and I said ‘We’re not putting him to sleep’.”

Scottie later returned home, and with help and advice from vets and the Equine Grass Sickness Fund (EGSF), he was nursed back to health.

“It took about eight weeks before he could swallow properly, and he used to have six tiny soupy feeds a day, but things got better,” said Lorraine.

“There were always little signs afterwards, for example his poos were never as big as they used to be, and his energy levels were never quite the same, but I tried to retire him three times and he was having none of it. From there on I used to just let him choose the pace, sometimes we’d tootle along on a hack, and other times he’d see an open gate to the field and we’d have a blast.”

Over the years Scottie remained healthy, and Lorraine stayed in touch with the EGSF team, attending grass sickness conferences, fundraising for the charity, and helping raise awareness of the disease.

In 2022 Scottie led the EGSF grass sickness survivors’ parade at the Royal Highland Show, and later that year he attended the World Clydesdale Show as an ambassador to raise awareness about the disease. It was the first time in history the show had been held in the UK, and it was here Scottie gained international fans – and formed a friendship with British Horse Society president Martin Clunes.

“At the Royal Highland and the World Clydesdale Show we had so many people come up to meet Scottie and ask about grass sickness. There’s still so many people that haven’t heard of it or think it’s just a northeast Scotland problem, but we’re seeing more cases pop up in places it hasn’t been before,” said Lorraine.

“When Martin met Scottie it was brilliant and he took such an interest in him and in learning about grass sickness. He returned a few more times to see Scottie and brought his wife Phillipa to meet him.”

Last April, two months before his 24th birthday, Scottie became unwell and was attended to by a vet, but he died suddenly. Although it was not possible to confirm the cause, it was suspected that there could have been links to his having had grass sickness.

“I had been checking on him every 20 minutes through the night had popped inside, then I heard a loud noise and he was gone. The one thing that sticks in my head is that I wasn’t there in that very moment, but people have said he probably waited until I was gone because he’d have known how upset I would have been,” said Lorraine.

Lorraine is running an online show in memory of Scottie and raising money for EGSF. The Mitchelhill Scott show has a range of classes, including heavy horse, veterans, and breed-specific sections, novelty classes and a grass sickness survivor class.

The show is open to all and will be judged via photographs. Entries close on 30 June, and the results will be announced no later than 7 July.

• Visit the show Facebook page for further information or email hagathabryn@sky.com.

“We have some brilliant judges from as far as the USA and Australia, and Martin Clunes has agreed to judge the heavy horses and the overall championship,” said Lorraine.

“We have managed to get sponsors for all the classes who have paid for the rosettes, which means every single penny will go to EGSF. The more entries we can get the better.”

Lorraine added that it means a lot to raise money and support for EGSF, and to host the show in memory of Scottie.

“The people at EGSF have become friends, even though it was eight years ago that Scottie had grass sickness. It is such an awful disease and nothing is too much trouble for them, they give so much support to people – and we all want the same goal,” she said.

“Whether we will find a cure for grass sickness or not I don’t know, but we need to keep plugging away. Scottie was perfect, he was the kindest person, a huge gentle boy, and even though he’s not here anymore I’m trying to do our bit and give something back in his memory.”

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Growing equine guts in a laboratory and determining weather that might cause equine grass sickness (EGS) are among the cutting-edge research projects aimed at beating the disease.

Experts from different backgrounds shared steps being taken, at a webinar organised by World Horse Welfare with the Moredun Foundation Equine Grass Sickness Fund (EGSF) on 10 April.

“It’s a really complex disease, and there’s still an 80% mortality rate, which is really sad, after all this time,” said Beth Wells, who leads the EGS research at Moredun. “We’ve known about EGS for over 100 years and we still don’t know what the causal agents are.”

EGS is a highly complex disease thought to be multifactorial in origin. The clinical signs are non-specific and there is no reliable diagnostic test for it, which Dr Wells said “we desperately need”.

Dr Wells explained that one of the many issues encountered in researching EGS was the lack of samples. Since the EGSF set up a biobank in 2021, supported by the British Horse Society, samples of tissue from affected horses have been collected, which are available for researchers to work on, along with data from reported cases.

Among those using the samples is Tanith Harte from Moredun, whose background is in neuroscience and immunology so who has a different perspective as she investigates causal agents of EGS.

Dr Hart explained that neurons die in EGS but it is not known how; finding this out could lead to identifying the pathogen, virus or bacteria that causes the disease.

“One major issue is there’s no way to model EGS; I don’t want to give it to any horses but we need a way to model the complexity of the gut,” she said. “Organoids are miniature organs derived from stem cells, and the gut renews itself at least once a week – so we can take stem cells and regenerate guts in the lab.

“They retain the properties of the animal they come from – so a horse with EGS or a healthy one – so later we can test anything we think is a causal agent.”

Hayley Coulson, whose PhD is in glaciology, is also using data collected as part of the biobank scheme to investigate meteorological conditions associated with EGS, in hopes of creating a predictive risk-based model.

“My aim is to identify the unique conditions linked to cases and so be able to predict high-risk times,” she said. Dr Coulson explained that once a case and its location are reported, she can find out the weather conditions beforehand. She did not want to be too specific about her findings before her research is published but said she has found the worst risk is “laminitis weather”.

“When there are big swings in temperature; nice and warm in the day and dropping to near freezing at night, I will be thinking danger time,” she said, adding that another risk factor may be a lot of rainfall breaking a drought.

There is advice on how to mitigate risky conditions on the Moredun website, including taking horses off pasture at certain times of day, and Dr Wells said she is happy for anyone to contact her for advice.

All three scientists agreed that it is vital owners and vets report any cases of EGS and contribute samples if possible, thanking all those who have done so, and all three stressed the importance of collaboration in tackling the disease.

“It’s been over 100 years but research is ongoing and we’re working towards finding a cure and a cause,” Dr Hart said.

Dr Coulson added: “Thank you. And please keep reporting.”

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Vets, researchers, and fundraisers have gathered to make progress in “solving the equine grass sickness puzzle”, agreeing that collaboration and awareness is the way forward.

These were some of the key themes at the Equine Grass Sickness Fund (EGSF) conference last month (29 March), where a number of researchers gave presentations, and panel discussions tackled raising awareness of EGS and fundraising.

Chris Proudman of the Surrey Vet School presented on the “power of partnerships” and that working with different specialists could help tackle the disease. He said pathologists, immunologists and microbiologists can all play a role, as well as sociologists and psychologists, who could help understand how human behaviour might have an impact on the incidence of grass sickness.

“There are plenty of people from other disciplines that could potentially help us in understanding the disease and effective preventative strategies,” he said.

During a panel discussion, vets tackled some of the challenges faced in dealing with EGS and the need for more awareness of the disease.

John Keen, of the Royal (Dick) School of Veterinary Studies, said it is very hard to tell the difference between an acute grass sickness case and an acute presentation of colic.

“We take a lot of care trying to delineate the different factors that are going to help us with our diagnosis, it’s like a big jigsaw puzzle,” he said, adding that vets consider the risk factors such as the animal’s age and whether it is coming from an area or premises with previous grass sickness cases.

“But undoubtedly we do get cases where it’s hard to tell the difference between the two, because a lot of the clinical signs are very similar – a high heart rate, distended small intestines, nasogastric reflux. If we didn’t have a really good clue whether it was grass sickness or acute colic, we would tend to send the horse for surgery to try to make that diagnosis,” he said.

“Undoubtedly, if we can develop better ways of trying to help us with that diagnosis of acute grass sickness or acute colic, then all the better, whether that be in the clinical sense or when we take a horse to surgery.”

It was acknowledged that the national biobank set up by the EGSF in 2021 plays an important role in helping researchers understand the disease. Biobank samples can include blood, urine, faeces and saliva samples from horses who have been diagnosed with EGS – and tissue samples from horses who have not survived.

The panel agreed that awareness of EGS and the biobank remains limited in areas, particularly outside Scotland. IVC Evidensia equine group veterinary advisor Graham Hunter said he believes that engaging directly with vets is the way to tackle this.

“We need a better way of disseminating the information further than just the northeast of Scotland,” he said.

The challenges around asking owners to provide tissue samples following the death of horses were also discussed.

“In Aberdeenshire, most owners are very aware of grass sickness and the biobank – if they don’t know about it, then a friend does. We haven’t had a case where we haven’t done a post-mortem and sent samples [to the biobank],” said David Miskelly of Woodside Vets, who added that they encourage clients to provide samples “for the greater good of the horse population”.

Mary Jo Grant, of Conanvet in Dingwall, said that although she finds clients will recognise grass sickness, a challenge is then getting them to accept vets taking samples.

“I think that’s where we now have to engage our time. At the time, it’s a very emotional situation that you are dealing with,” she said, adding that it might be beneficial to have conversations about things like providing post-mortem samples with owners of healthy horses.

“It’s a bit like humans with organ donation; the conversation should be had so if at a point this does happen, what are your wishes?”

Dr Hunter added that he believes owners are engaged about equine grass sickness, but the issues include educating them on the biobank and post-mortems. It was suggested that it could be worth referring to the procedure of taking biobank samples as “tissue retrieval” instead of a post-mortem, which could be received by some owners as “too clinical”.

Beth Wells, of the Moredun Research Institute, said the “forward plan is working together”.

“We’re very keen to be as inclusive as we can within research and outside,” said Dr Wells.

“We are in the middle of a recruitment process for a new researcher and they will be concentrating on pilot projects. That pilot data will then be used to submit funding applications with collaborators, so what we really need is to run the pilots, get the preliminary results then we have something to work with.”

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The owner of a horse who survived grass sickness – as well as almost losing an ear – says she “never thought I’d see the day we were competing and enjoying life together”.

Diesel, and his owners Jane Robinson and her daughter Ellemae, have been on “quite a journey”, over the past 16 years, since the Fell arrived as a young colt.

“I’m so proud of him; we’ve still got him, and proud of her,” Jane told H&H.

Jane said the Fell pony was away to be backed, years ago, when he degloved his ear in a freak accident.

“The vets had never seen anything like it,” she said. “He tried to get through a hedge, hit his head on a tree and fell in a ditch and there was nothing on his ear. He had to have lots of operations, and skin grafts from his girth area, and it was a bit touch and go.”

Diesel’s ridden career was then put on hold, and two years later, he was back at the vet’s.

“He wasn’t right and when I rang the vet, he said ‘It sounds like grass sickness’,” Jane said. “I said ‘What’s that?’ and he said ‘He’ll be dead within 24 hours.”

Diesel arrived at the clinic “sweating and shaking”, and his prognosis did not look bright.

“He looked like a greyhound within 24 hours,” Jane said. “He didn’t eat or poo for four days. I went to Tesco to buy him some chopped-up carrots, and I think that’s all he ate for 50 days. The vet said if he got to 50 days, he had a chance.”

Diesel spent a week at the clinic, then went home, where Jane monitored his every move.

“I lived in his stable; it was just lots of TLC,” she said. “If he wouldn’t poo, I used to go and get a mare’s poo and put it next to him, to encourage him, but it was love and care and lots of carrots that got him through.”

By the time Diesel and Ellemae were 14 and 13 respectively, in lockdown, Ellemae had lost her previous pony Merrylegs, and she asked her mother if she could back Diesel.

“I wasn’t sure it was safe but she wanted to do it,” Jane said. “But she took him on and they rode round the farm; it was like he had done it all before. She started social media accounts on his journey, and it’s all just escalated. They’ve become best friends.”

Ellemae is now an ambassador for and sponsored by equestrian brands, and she shares her and Diesel’s story, hoping to raise awareness of grass sickness.

“A vet saying you have nothing left to do for him and you have less than 48 hours with your horse is absolutely tragic,” Ellemae told H&H. “I never thought I would ever see the day we’re going out competing and enjoying our life together. He’s amazing.”

“I never thought she’d back him and ride him,” Jane added. “She’s now bought herself a trailer and is hoping to get out to competitions. She’s off to the National Equine Show as their ambassador, and she’s done this all herself. For him to go through what he has and be backed at 13 – I never thought I’d see that.”

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A Welsh cob who would probably have been put down had his diagnosis of grass sickness been made sooner is back to winning ways in the show ring.

Katie Nuttall’s Welsh section C Llanidan Dunkirk was four when he came down with the chronic form of the disease, in late 2019. On 6 March this year, he won the mountain and moorland large breeds class at the Northern Counties Pony Association Spring Spectacular.

“It’s incredible he survived,” Katie told H&H. “He didn’t have a poo for five weeks; it’s unbelievable he’s still here.”

Katie bought “Kirk” as a three-year-old and he had been backed and turned away by autumn 2019.

“One day he looked amazing, the next, he had no weight at all and wouldn’t eat,” Katie said. “He came down with it in November but I had to get a second vet’s opinion and he wasn’t diagnosed till December. If I’d known earlier, I’d probably have had him put to sleep but by the time we found out, we’d kept him alive that long; we had to give him the chance.”

Katie did not think Kirk would make it, owing to the severity of his illness.

“He would just stand in his stable shivering, and the sound of his breathing — it was awful,’ she said. “But when he had that first poo, I thought ‘this is it’.”

It was a long slow haul to recovery for Kirk, but by October 2020 he was well enough to be gelded. A year later, he was brought back into work, and he has gone from strength to strength.

“He struggled with eating if the food wasn’t wet enough; you’d hear him squealing, but touch wood, he’s back to normal now,” Katie said. “When people hear what happened, they say ‘How did you keep him alive, and how is he looking so good?’

“The pony he is; you could put a five-year-old on him and he’d be good, then put a professional on him and he’d go into show mode. You can do anything with him.”

Katie is now aiming for Horse of the Year Show and Royal International Horse Show qualification, with Ella Hodgkinson on board for the junior ridden classes and Rachael Nesbitt for the novice working hunters.

And Katie hopes Dirk’s story might help other owners in a similar situation.

“If the vet had said it was grass sickness straight away, I’d have had him put to sleep; I’m so glad I didn’t,” she said. “If you see the pony he is today, it’s unbelievable.

“It wasn’t easy and it cost me a fortune — but it was worth every single penny.”

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Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade your subscription to access our online service that brings you breaking news and reports as well as other benefits.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

A mare who developed grass sickness when she was eight months’ pregnant has recovered to give birth to a “miracle” foal.

At the end of 2021 Welsh mare Bluehaven Rock Goddess, known as Bambi, was found looking lethargic and unwell by her owners and breeders Julie and Carl Costello of Bluehaven Stud. The couple contacted their vet and following an examination Bambi was referred to Rainbow Equine Clinic.

Carl told H&H initially it was suspected that Bambi had colic, but vets carried out an eyelash test and Bambi – who was eight months pregnant – was diagnosed with chronic grass sickness. One of the clinical signs of grass sickness is ptosis, the drooping of the upper eyelids, and to test this eyedrops are used in one eye. In a horse suffering with grass sickness, the eyelashes will assume a different angle in the eye that has received the drops.

“It took a while to establish what was wrong with her. We were watching her go downhill as we were looking at her,” Carl said.

“At one stage the vets said the foal should be aborted because Bambi wasn’t eating a lot, and anything she was eating was going into the foal. Juliet and I discussed it and agreed we wanted to try and save the foal, but we said if at any point Bambi became in danger we would have to abort her.”

Bambi spent more than three weeks being in hospital and Carl said she began to “pick up”.

“We were trying to stimulate her to eat by trying chopped-up carrots, corn, slops – anything to try and help her,” he said.

“Then she just began to turn a corner. She got stronger and stronger and we were able to bring her home to continue nursing ourselves. At one stage a haynet would have taken her weeks to empty, but now she’s eating well.”

On 8 March Bambi gave birth to a filly, named Bluehaven Roxanne. Carl said maiden mare Bambi’s mother instincts “kicked in” but during the first few hours she had become very “foal-proud”, where a mare can become overly protective, and the foal initially struggled to suckle.

“We were concerned at first she wasn’t getting the colostrum she needed, but after some time they were fine. The foal is now bouncing around and doing well. Bambi is very proud of her, and we’re very proud of Bambi. We hope with time she will return to her former glory in the show ring and we’ll show the pair of them. She’s not 100% back to herself yet, but she’s a good 97%.”

Carl and Juliet have been in touch with the Equine Grass Sickness Fund and have provided tissue samples from Bambi to the charity’s biobank. The biobank was established last year with the aim of collecting vital samples from horses and soil to help with future research into the disease. For more information on providing samples visit www.grasssickness.org.uk.

“We’ve sent all the samples we can so hopefully they can learn something from them, as we have learned from the charity,” said Carl.

“We know grass sickness survivors are rare, and Bambi then giving birth to a healthy foal was even rarer. The disease takes no prisoners, and we’ve been extremely fortunate.”

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Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

Vets and owners are playing a “crucial role” in grass sickness research, as it is hoped a project launched this year could hold the “key” to understanding the disease.

In May, as a result of the Moredun’s Centenary Fellowship Project, a research fellowship was formed, funded by the Moredun Foundation and the Equine Grass Sickness Fund (EGSF), with support from the British Horse Society (BHS). Researcher Kathy Geyer was recruited and led a project to launch a biobank to collect samples from horses and soil, in the hope of providing more information to understand the risk factors of the disease.

An EGSF spokesman said previous research into the disease had been hindered by a lack of suitable samples, but since the launch of the biobank owners and vets are now playing a “crucial role”. To date, more than 1,000 biological and environmental samples have been collected.

“The success of the biobank project in its first season has been remarkable, thanks to the hard work of the team, partner organisations, volunteers and the growing network of equine vets and owners, who support the biobank by sending samples in and raising awareness of the project,” said an EGSF spokesman.

“We will continue to add to this over the next two seasons, so researchers have access to sufficient samples to make their research impactful. The support we have had from the horse industry, particularly the BHS, World Horse Welfare and Balmoral Stud’s stud manager Sylvia Ormiston, has been outstanding and very much appreciated. We are also working hard to encourage all vets and horse owners, throughout the UK and beyond, to support our biobank project.”

The next stage of the research will launch next year, with the Moredun Foundation and EGSF “teaming up” at a research event with scientists from a wide range of disciplines in the hope of “making a breakthrough”.

“It is highly likely that the key to this disease lies within these biobank samples, if we can ask the right questions,” said the spokesman.

“Due to the nature of this fresh approach, by making the project accessible to everyone with an interest in solving this devastating disease, we will continue to expand our networks and initiate multi-disciplinary, collaborative research projects to find answers to this devastating disease and to improve the health and welfare of equines.”

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A new approach to equine grass sickness research aims to shed light on the causes and risk factors of this disease. Andrea Oakes reports

CASES of equine grass sickness (EGS) typically peak during early summer months. While the causes of this often fatal disease are still unclear, more than 100 years after its discovery, a new biobank project aims to provide researchers with the information they need to make a breakthrough.

Dr Kathy Geyer, EGS research fellow at Moredun Research Institute, explains that the disease mainly affects horses that have access to grass – although there have been isolated cases in stabled horses.

“EGS has an extremely high mortality rate, with 80% of cases resulting in euthanasia on welfare grounds,” she says. “The clinical symptoms are non-specific [not due to any single known cause] and, without a reliable diagnostic test, diagnosis is challenging. As a result, many cases are mis- or undiagnosed, most likely leading to an underestimation of actual disease prevalence.

“What is evident is that EGS is a highly complex and enigmatic disease and therefore very challenging to work with,” adds Kathy. “Decades of research have led to various different hypotheses on the cause, but with a single causative agent yet to be confirmed, EGS is now thought to be of multifactorial origin.”

SAVING SAMPLES

SO what is the biobank – and how might it help?

“Progress in EGS research has been hampered by the lack of coherent sample collections,” says Kathy, saying that the Moredun Foundation and the Equine Grass Sickness Fund, with support from the British Horse Society, have launched the initiative.

“By collaborating with vets and owners, the biobank project aims to collect samples from EGS cases and co-grazer control horses that would otherwise be lost, so that horses have not died in vain. These samples will be available to any researcher working on EGS and will encourage an interdisciplinary approach in the search for the potential causes.”

These samples may be biological, such as blood, saliva or urine, or environment related, adds Kathy, and will be collected at no extra cost to the owner. Tissue samples are especially valuable. Since the course of EGS can be swift and frequently devastating, owners are encouraged to familiarise themselves with the project ahead of time – should the worst happen.

“There is just a small window of opportunity to collect the samples when grass sickness is suspected, so it would be helpful to think about and prepare for this in advance so these valuable samples are not lost,” she says.

“In addition to collecting samples, we are working with owners to encourage the completion of our case report questionnaire, which will give us valuable information about potential risk factors and general understanding of the disease.”

RISK FACTORS

HORSES can be affected by EGS at any time, but the spike in cases in spring and early summer is often followed by a second peak in autumn. Kathy explains that horses in eastern parts of the UK are at higher risk, with the north-east of Scotland having the highest incidence.

“There may be a weather-related aspect,” she says. “Vets and owners experienced with EGS are on high alert after a dry, but cool [around 10°C] spell lasting around 10 days, or periods with sunny days and intermittent ground frosts. Furthermore, younger horses appear to be at a higher risk, with a peak between two and seven years of age.

“The disease involves damage to the nerves in the digestive tract and other sites throughout the body, severely affecting the horse’s ability to swallow and impairing movement of gut contents,” she adds. “This can lead to complete paralysis of the digestive tract from the oesophagus downwards.

“Based on the underlying nerve damage and disease progression, there are three main forms of the disease: acute, subacute and chronic. Although euthanasia is generally the only option for acute or subacute EGS, under certain circumstances, treatment may be considered for chronic cases.

“With intensive and skilled care, around 50% of them survive,” Kathy says. “However, nursing a chronic case is physically, emotionally and financially demanding.”

For details about the biobank project and relevant downloads, visit: grasssickness.org.uk/biobank/biobank-for-horse-owners

This report can also be read in Horse & Hound magazine, on sale date 24 June 2021

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Owners of horses who have been affected by grass sickness are being urged to take part in a “crucial” new project to help protect equines from the devastating disease.

A new “biobank” has been formed, containing samples from horses and soil samples, that will play a role in future grass sickness research.

The project has been created by livestock health and welfare research charity Moredun Foundation and the Equine Grass Sickness Fund, with support from the British Horse Society (BHS).

“A lack of suitable samples from [equine grass sickness] cases has hindered research progress into the causal agents involved, despite the disease being recognised for over 100 years,” said a joint statement from those involved in the project.

“But horse owners and vets can now play a crucial role in this project by submitting samples from affected horses and field controls, along with soil samples, to the new biobank.

“In future, scientists researching [the disease] will be able to apply to use the anonymised samples in projects aiming to establish the causal agents and break new ground against the disease.”

Equine grass sickness has an 80% fatality rate. It can occur at any time of year, but is found to be most prevalent between April and June.

“By donating samples and completing case questionnaires, horse owners and vets can provide valuable information helping researchers understand the risk factors and protect future generations of horses and their owners from the terrible effects of this disease,” added the statement.

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Dr Beth Wells, principal scientist and knowledge exchange specialist at Moredun, said the charity is delighted to be working in partnership with the Equine Grass Sickness Fund to develop the national biobank.

“This is essential for research to progress and the samples will be available to all researchers,” said Dr Wells, thanking the BHS for its “generous funding”.

“We are very grateful to all the horse owners and vets who have already provided samples, at such a difficult time for them, and we urge everyone to think about supporting us to help find the cause of this devastating disease.”

For more information, visit the Equine Grass Sickness Fund website

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The owners of two equine grass sickness (EGS) survivors have launched an awareness week in the hope of “giving something back” and helping other owners.

Basingstoke-based Sarah Hatter and Rhiannon Boyle from Essex will launch the first EGS Awareness Week from 29 March to 4 April. The week will provide facts, scientific information and advice about the disease with input from veterinary experts, feed companies and other owners of grass sickness survivors.

Sarah told H&H she and Rhiannon became friends after discovering each other on Instagram when their horses were going through chronic grass sickness at the same time in summer 2019.

“I had come home from university and the yard said Milo hadn’t been eating or pooing as much,” said Sarah. “He was initially treated for colic and underwent surgery where the vets found a small twist, but they decided to take a small biopsy, and he was diagnosed with grass sickness.

“It was so hard-hitting, and I was told he probably wasn’t going to make it. I just burst into tears uncontrollably. That day my mum Jane took me to the vets for us to say goodbye.”

Sarah said when she arrived at the vet clinic, then six-year-old Milo seemed “bright and perky” and it was decided to give him a chance.

“Seeing him get through the first 48 hours suggested it wasn’t acute, then making it through the following two weeks meant it was unlikely it was subacute. Being a chronic case meant he had a better chance,” she said.

“I have a horsey Instagram account and posted about my Milo having EGS. Rhiannon commented and said her horse Stripe had been diagnosed too and we started speaking from there,” she said.

Milo lost more than 80kg and spent a month in hospital, during which Sarah visited him every day, between sitting her university exams.

“I couldn’t not see him, I just had to and when I left he would become quite down again,” she said. “He had an amazing team at Donnington Grove vets looking after him; vet Imogen Comyn fought so hard for him and vet nurse Leah Grange would spend nights sitting with him. He really thrived on human company so I am so grateful for everything they did for him.

“It was a really long process, some days he would only eat three Polos – then the next day it might be four. I kept a diary and looking back one day he had a jam doughnut, which he loved!”

Sarah said Milo continued to recover at home and by September had regained his strength and started to put weight on. He has since returned to full work and the pair are now enjoying taking part in online dressage. Eight-year-old Stripe, who Rhiannon got from the Blue Cross in 2015, has also made a full recovery, and returned to competing in dressage.

“Rhiannon and I know a lot of cases don’t make it, but when Milo was ill all I read was negative stories and we want to give people some hope. I had never heard of EGS before and at times I would think ‘Am I stupid trying to get him through it?’,” said Sarah.

“It’s was so lovely meeting Rhiannon and just shows that social media can have a positive side. We never thought our horses would make it and we know we’ve been lucky with Milo and Stripe so we really want to give something back. We’re so passionate about raising awareness of EGS and hope this could become an annual week.”

The focus will be on the Equine Grass Sickness Awareness Week Facebook and Instagram pages.

Kate Thomson of the Equine Grass Sickness Fund told H&H the charity is keen to support Shannon and Rhiannon and will promote the week.

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“It would be very exciting to think that this could become an annual event,” she said.

“There are still so many questions surrounding the disease, and we are currently launching our biobank to help us address these questions. We are relying on horse owners and equine vets to work with us to collect as much information as we can about the cases that occur, and we are hoping that Sarah and Rhi will highlight this important role that horse owners have to play.”

An EGS webinar about the biobank will take place on 25 March. More information can be found at the EGSF website.

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The launch of a five-year research plan hopes to “shine a new light” on equine grass sickness.

The Equine Grass Sickness Fund (EGSF) has revealed its plans for 2021-2025 as the charity works together with scientists to look at the disease in “new ways and from fresh angles”.

A spokesman for EGSF said the research will be focused on the charity’s aims; cause, prevention and treatment.

“There are still questions to be answered about specific causal agents, and these will remain a focus of research, including mycotoxins and clostridium botulinum,” he said.

“We will also undertake an open-minded review of what has been done to date, and establish the known facts, in order to identify promising new angles for investigation. Equine grass sickness seems likely to be multifactorial, so a cross-disciplinary approach may produce dividends.”

The five-year plan will include work by newly recruited research fellow Kathy Geyer, while Bruce McGorum, head of the equine section at the University of Edinburgh, will take a research sabbatical from the Royal (Dick) Vet to focus on work looking at mycotoxins. A PhD student will also be recruited to work with Kathy in the laboratory developing organoid cultures, which involves recreating a piece of horse gut using cells, which can then be tested.

“Kathy is going to review all of the research done to date and take a view of where we might go next and what we might have missed,” Kate Thomson of EGSF told H&H.

“The plan is to bring in lots of scientists from different fields. Traditionally there has been a lot of equine vets looking into grass sickness so we now want to look at it from an environmental point of view and will have soil and plant experts feeding into the research.”

EGSF is recruiting horse owners and vet “ambassadors” to assist the charity in collecting samples for its biobank.

“There is a shortage of samples to use in the testing so we want to recruit vets that can help us with the horse samples and we need owners to be our eyes and ears by helping encourage people to report cases to us.

“There’s so much knowledge out there; we have the knowledge from scientists, but the owners and vets are the people dealing with grass sickness cases. They’re seeing what the weather is like, they know what the horse was doing the week before, when it was wormed, and all these different things. We don’t have enough of this information so we’re trying to bring the two together so that the people are helping inform the research going on and we can feed back on what we’re finding out.”

Kate described the five-year plan as “exciting” and a positive new approach.

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“We’ve done a lot of great work so we’re saying ‘let’s gather it together, take a step back and review it’. We’re not dropping the theories we’ve already got because we think they all fit together somehow, but we just don’t know how yet,” said Kate.

“We’ve put the research into a five-year format so we have a specific date where we can say ‘where are we now?’ and ‘where do we go next?’. As soon as we work out what causes grass sickness, then we can work out what prevents it, which would be just amazing.”

EGSF plans to launch a series of webinars in March with more information on how people can support the charity and become involved.

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A vet who is running 100 kilometres in a month in aid of equine grass sickness hopes there will one day be a cure for the disease, and said telling an owner their horse has the condition “never gets any easier”.

Mairi Sinclair, of Ardene House Vet Practice in Aberdeen, took on the challenge of running 100km in October while raising funds for the Equine Grass Sickness Fund. The charity undertakes vital research into the disease and provides support and information for owners.

Mairi, who is a keen eventer, told H&H the challenge started off as a personal goal while she took a year out from riding, but she decided to turn the challenge into a fundraiser.

“I’m definitely not a runner but I think running is one of those things if you make a start it’s amazing how quickly you get used to it,” she said. “I started doing a few days of 3K and a week of 4K and now I’m running 5K five times a week.

“Because I don’t really run I wanted to make sure I’d keep doing it and my body was holding up before I created my fundraising page. To start with I thought if I can raise a couple of hundred that would be nice, but it’s gone crazy since then!”

Mairi said it was an easy decision to raise money for grass sickness.

“Of all the things we see as vets, grass sickness is one where your heart sinks as soon as you have to list it as a possible diagnosis,” she said. “As many people know it’s an absolutely horrendous condition to deal with and there’s very rarely a positive outcome.

“In Scotland we see probably more cases than the rest of the UK and as a practice we see several a year. The difficult thing is a lot of clients become friends over the years, so having to tell someone I consider a friend that’s what their horse has and there’s nothing we can do, never gets easier and it never will.”

Mairi said people often used to think grass sickness only occurred in young horses.

“I’ve seen 17-year-olds and 11-year-olds with it, and horses that have been on a yard for years or only just arrived at a yard – it doesn’t seem to follow the rules that we think it should,” she said. “We do get some chronic cases that survive but usually that is through a very long recovery, and the owners who get their horses through that are usually emotionally and physically exhausted by the end of it. It’s certainly not something to go into without being prepared for any outcome.

“We all want to treat horses and make them better and grass sickness is one of those conditions that no matter how early we suspect it there’s no treatment or preventative thing that we can do and that’s awful.”

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Mairi has run 57.6km to date and raised £1,350.

“I’ve got eight 5Ks then a 3K left – which sounds a lot when I say it out loud but I’m slightly ahead of schedule. It’s been a challenge but because I haven’t been riding it’s slotted into that gap and I’ll run before or after work. Knowing it’s a fundraiser is really powering me on,” she said.

**Mairi’s JustGiving page**

“I’m so amazed by how generous people have been. The total I’ve raised so far has certainly made every kilometre worthwhile. A lot of people who have donated have said either they’ve had a personal experience with grass sickness or they live in fear that one day they’ll hear those words from their vet about their horse. Everyone wants the same solution – either to be able to treat it or prevent it.”

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An “innovative approach” to equine grass sickness (EGS) research could provide answers on the disease – as owners are encouraged to report cases.

The Moredun Foundation and the Equine Grass Sickness Fund (EGSF) have joined forces to launch a three-year fellowship to “breathe fresh thinking” into research into the disease. The fellow will be based at Moredun’s International Research Institute, with their main objective to set up a national database and sample biobank collating samples from horses, soil and plants.

Kate Thomson of EGSF told H&H the new project is about “taking a step back” and looking at what is missing from current research.

“One of the problems we have at the moment is there isn’t any sort of coherent collection of samples that scientists need for research. We plan to engage the considerable expertise among owners and other equine charities as ‘EGS detectives’ in submitting case reports and samples to the biobank,” she said.

“The fellow will be supervised by a steering group of experts and will have access to scientists all over the world from different fields such as grass, fungal and botanical experts. We hope that by building the biobank, scientists will able to answer questions such as ‘what’s different, why did that horse get it, and why did the other horse not?’.”

Kate added the charity only receives around 40 case reports of the disease per year in the UK.

“You just have to look at social media and you’ll see at least double that number of cases and we’re not being told about them. We really need people to get in touch if they’re dealing with a case,” she said.

“Often when there is a case of grass sickness the owner is devastated and has all sorts of other things to worry about, so if we can let people know about this before they ever have a case, even if it’s just a report to tell us what has happened, then we’re in a much better place. We really hope owners will become enthused about this project,” she said.

Kate added a new research update booklet produced by EGSF, with funding from British Horse Society (BHS) and World Horse Welfare, helped the charity create the idea of the fellowship.

“We are very grateful to the BHS and World Horse Welfare for helping us produce the update which helped pave the way for this project,” she said.

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Beth Wells of Moredun added that the fellowship brings together a “truly multi-disciplinary team” working in collaboration to provide new approaches.

“We are very grateful to the Moredun Foundation and EGSF for their foresight in funding this post which, as well as taking forward new ideas and research strands, will involve extensive engagement with vets and owners to establish the database and biobank,” she said.

Sylvia Ormiston, stud manager of Balmoral Estate where The Queen’s Highland ponies Balmoral Lord and Balmoral Hercules were lost to the disease in 2018, said she is excited about the new approach to research.

“As a stud manager and pony owner I know only too well of the damage this dreadful disease can do and I am happy to support the research in any way I can. Together we will hopefully make some progress to try and beat this baffling disease,” she said.

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A rider who is raising money for the Moredun Foundation Equine Grass Sickness Fund (EGSF) by taking part in a virtual marathon will be joined on the final stretch by her gelding who survived the disease.

Vicky Sinski’s now 11-year-old Welsh section D Alfie was diagnosed with chronic grass sickness in May 2017 and spent six weeks at Hambleton Equine Clinic, North Yorkshire.

“When the vets said it was grass sickness I thought I was going to lose him. I was told he had a five percent chance of survival,” Vicky told H&H. “It was a case of taking each day at a time, with grass sickness you just have to deal with what’s in front of you each day.

“Alfie is usually energetic and boisterous so it was horrible to watch him so depressed and losing weight. People say with grass sickness, it’s up to the horse if they want to survive and personality has a lot to do with it – I know Alfie so well having owned him since he was nine months old and I somehow knew he wanted to keep going.”

During his time in hospital Alfie lost 150kgs. Once he started showing signs of improvement, and an interest in food, he returned home in mid-July.

“It was really difficult as you don’t like to let yourself get too optimistic,” said Vicky. “At the back of my mind I was constantly worried he would colic, and he still wasn’t drinking. I remember looking at him, amazed, and thinking ‘how on earth are you still alive?’

“The staff at Hambleton were amazing, they really fell in love with him, and when I got him home, I got so much support from everyone at the yard. I work full-time and when I was working people were always helping, everyone was so invested in him.”

Vicky said Alfie continued to improve – bar one episode of colic that winter. He returned to ridden work in summer 2018.

“He has gone from strength to strength. It took almost 18 months for him to put weight back on and he does tend to lose a bit in winter so I don’t ride him much then, but he just loves being back in work,” said Vicky.

“He can no longer swallow hay or haylage and only wants to eat grass, and it took six months for him to drink out of a bucket again, but with a survivor you learn to deal with the quirks they develop.”

During Alfie’s illness Vicky sought advice from EGSF, which put her in touch with the team at The Dick Vet Equine Hospital in Edinburgh that specialises in the disease. Last year she contacted the charity about running the London Marathon on its behalf. The marathon was cancelled owing to the coronavirus pandemic and Vicky’s place has been deferred to next year’s event, but a virtual event will take place on 4 October, when participants have 24 hours to complete 26.2 miles.

“I enjoy running and had always wanted to do the London Marathon so to do be able to run it for EGSF would mean a lot,” she said. “Everyone who had a place in this year’s marathon was offered a place in the virtual event. I had stopped training after it was cancelled but I feel I can confidently run the first half, then the plan is to run and walk the second half.

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“I’m going to run a route starting from my home in Darlington and friends and family are going to join me for three- to five-mile slots. I’m going to be running past the yard, and Kate Thomson of EGSF suggested doing the final four miles with Alfie. We’ll do it in hand round the grass tracks at the farm and have a finishing line with flags.”

Vicky hopes to raise £2,000 for EGSF and raise awareness of the charity, and the disease.

“Still so little is known about grass sickness and I feel bad that before Alfie became ill I wasn’t aware of the charity,” she said. “People need to know about the important work EGSF does and they desperately need the support if we ever want to find a cure or what causes grass sickness, it shouldn’t be the death sentence that it is.”

To donate visit Vicky’s Virgin Money Giving page. 

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Highland ponies belonging to The Queen are among those due to star in a charity calendar raising vital funds for and awareness of grass sickness.

Heald Town Highland Pony Stud, owned by Carolyn and Melody Ashcroft, is creating its annual calendar in aid of the Moredun Foundation Equine Grass Sickness Fund (EGSF), for which they raised over £4,200 last year.

The 2021 calendar will feature Heald Town stallions seven-year-old Ghamjon Ernie and four-year-old Glenmuick of Coynach, and some of the stud’s foals. It will also again feature some of The Queen’s Highland ponies from Balmoral Stud, managed by Sylvia Ormiston.

“If lockdown allows, the plan is I will spend five days at Balmoral at the end of the month taking photographs of the ponies in their natural environment and doing the job they were bred to do on the hills,” Melody told H&H.

“Highlands are an absolute pleasure to photograph. Their temperament really comes through, they are so strong and powerful, but such kind ponies with what I would describe as old souls.”

Melody said she was “over the moon” about the amount of money raised last year and was delighted to be supporting the charity again.

“People still don’t know enough about grass sickness, so doing the calendars isn’t just about the money, it’s about raising awareness of the disease and helping people to understand what it is,” she said.

“Last year when the calendars went on sale we had so many people get in touch asking us about the disease and asking for advice so it’s nice to be able to point them to the right people at EGSF for help.”

Melody said grass sickness has a huge impact on so many in the equestrian community. A gelding bred by Melody, Heald Town Drumlin owned by Samantha Kay, was lost to the disease in 2019 and two of Balmoral Stud’s stallions, Lord and Hercules, were put down in 2018.

“We still don’t know what causes it and there are still so many cases that go unreported or unconfirmed,” she said.

“After the loss of Drumlin, and the Balmoral ponies, we really wanted to pay tribute to them and give something back by contributing towards finding a cure one day.”

A public vote will decide which photographs will star in the calendar, opening on Heald Town’s Facebook page on 1 August.

“We really like engaging with the public on the calendar. This is the sixth year we’ve done it, the third for EGSF, and people get really excited about it,” said Melody.

“We hope to start selling the calendars on 1 October and they will remain at £12 including postage.”

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The Highland mare, who was diagnosed with grass sickness in 2016, overcame losing a filly in 2017

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Kate Thomson, of EGSF, said : “I am delighted to work with Melody again on the calendar, last year’s was an incredible success. The Highland pony breed has had some terrible losses to grass sickness, including very valuable breeding stock, and it is fitting that we can work together on this project.

“We hope to soon appoint an ‘equine grass sickness fellow’ to work here at Moredun. The fellow will take a systematic look at all the research done to date to establish exactly what is known to date, and will work with experts across all scientific disciplines to shed new light on the disease. The proceeds from the calendar will be absolutely critical in supporting this new project.

The calendars will be available to buy online from Heald Town Stud and the EGSF website or from Edinburgh’s Royal Dick Vet and the Balmoral Castle gift shop.

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A Highland pony mare “who chose to fight” grass sickness and overcame losing a filly, has given birth to her second healthy foal since surviving the disease.

Fife-based Jo Jack’s pony Annie (Nighean An Dalaich of Murrayshall) was diagnosed with grass sickness in June 2016 while at stud as a four-year–old.

Jo, who has lost four ponies to grass sickness in 25 years, told H&H her “heart sank” when stud owner Mary McCall Smith called with the news.

“Because I’d lost four to acute and sub-accute grass sickness in the past I assumed there was no chance Annie would survive,” she said.

“Mary’s vet gave her 24 hours, and there were many times you thought that was going to be it, but then she would rally.”

Annie remained at the stud with Mary, while Jo made the three-hour journey to visit when she could.

“We realised very quickly Annie didn’t want hard food and we didn’t want to force her, but we found she still wanted to eat grass. We believe it was Annie who made the decision to survive,” said Jo. “As I wasn’t seeing her every day, I could really see the differences when I did visit, initially this meant I saw her get worse as she lost weight but as I went back I could then see her getting better.

“Mary was fantastic and would let Annie move around fields so she was always getting the grass she wanted, and one day Mary found her pinching her sheep food and we knew she’d turned a corner.”

Jo said Annie lost around 150kg while she was unwell but around nine weeks after her diagnosis, was scanned in foal.

“Mary was having some mares scanned and decided to scan Annie but we never thought there would be an embryo in there after what she’d been through.” she said. “It was shock and I was terrified thinking how we were going to keep enough condition on her.

“I took her home in October and she eventually began enjoying food again. She’s such a fighter, I wondered if she knew she had to eat for her foal.”

Annie foaled on her due date, 29 April 2017, but within 20 minutes of the filly being born, Jo said she noticed something was not right owing to the noise of the filly’s breathing. She was found to have an issue with her soft palate, and after three weeks of treatment was put down.

“It was absolutely heartbreaking, she was so beautiful and Annie was the perfect mother,” said Jo.

“The vet said it could have simply been unlucky, or it could have been something to do with her development when Annie had grass sickness, but we won’t ever know.”

Jo put Annie to stud again that year, and in March 2018 she gave birth to a healthy filly, Saffron – known as Saffy.

“Annie is a very good mum, she isn’t a stressy mare which we think is what helped her during her fight,” she said.

“Saffy has proved to be a real diva, she struts around pretending she’s the boss.”

The following year, Jo agreed to produce a pony belonging to the Munro family of Loandhu Stud and in return she was offered the opportunity for Annie to go to stud. On 8 June 2020 Annie gave birth to a healthy colt, named Rory, by Strathmore Cameron.

“Alan and Carolyn Munro have been absolutely superb, lockdown happened and they’ve done all the hard work. They’ve already had four fillies of their own and have been patiently waiting on Rory arriving,” said Jo.

“Alan has been sending me lots of photos and videos and Rory is already so friendly. I’ve been very lucky to have the support of the whole Munro family, Annie wasn’t the easiest mare to put there, as a grass sickness survivor, but they’ve made sure she had the best grass and taken such good care of her.”

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Jo hopes to bring Annie and Rory home once lockdown restrictions allow.

“Every year Annie has been looking better and better, she’s such an accepting mare and if she hadn’t chosen to fight I don’t think she’d still be here,” said Jo.

“I still take each day as it comes, and when people ask what will be next for Annie or for her foals I always say I’ll wait and see what happens next. Losing four to grass sickness and then going through it with Annie has been a great leveller; I don’t like to plan too far ahead and prefer to make small goals because you can be so easily disappointed.”

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It’s clear round, Jim, but not as we know it.

Goats, cats and dogs, not to mention an Oompah-Loompah with Woody and Jessie from Toy Story, have been showing their turn of hoof (or paw) on a course of jumps.

Yvonne Maclean has raised some £47,000 for the Equine Grass Sickness Fund during the past six years, since her own horse Malbec recovered from the disease, but her plans to increase the total this year have been scuppered by the coronavirus.

“In 2014, my five-year-old took sick with grass sickness,” Yvonne told H&H. “He had 14 weeks of nursing and he got through it but it was a long struggle, and it nearly cost me my marriage.

“We came out the other side and the next year, I decided to run a show to raise money, but have it like a gymkhana, so it was all about having fun. We made about £5,700 and it’s gone from there.

“This year, though, fundraising has come to a standstill.”

Yvonne set up a Facebook group for fundraising for the charity, and came up with the idea of “clear round to pound grass sickness”. Everyone who takes part donates to the fundraising page if they can, and nominates five others to have a go.

“I did it first with my goats – and it was absolute carnage,” she said. “I’ve got about 20; I breed pygmy goats and have some bigger rescued ones and they’re always running around the garden anyway so I just put some ‘jumps’ up, and of course they didn’t do what they were told, it was mad!”

Yvonne said as the challenge was started when riders in England were still being advised not to ride, as is still the case in other home nations, she did not want to encourage people to jump horses.

“People have done it with dogs and cats,” she said. “My husband did it in a horse costume, with the dog, and nominated five people who have got kids, and the feedback from them was unbelievable.

“One had a four- or five-year-old girl who spent all day making and painting her cardboard box jumps, then did it in her little Horse of the Year Show jumper, a lad from Inverness did it with his kids dressed up as Woody and Jessie, and he was an Oompa-Loompa, and he said they were excited about it all day.”

Yvonne said her motivation to raise funds was sparked not only by her horrific experience of grass sickness, but also that she felt very alone as no one she knew had had to deal with it. She wants to raise awareness of as well as money for the fight against the disease.

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“There are 6,600 people on the grass sickness awareness Facebook group; if they all gave the equivalent of £1 a month, that would fund a researcher for a year,” she said.

“I know not everyone can donate at the moment but please, do the challenge anyway as you’re still raising awareness, and if you nominate other people, they might be able to donate. And if those videos don’t bring a smile to your face, nothing will.”

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• This article has been edited and approved by Karen Coumbe MRCVS, H&H’s veterinary advisor since 1991.

Grass sickness: Risk factors | Signs | Diagnosis | Treatment | Causes | Prevention

Grass sickness is an often-fatal condition that typically occurs in grazing horses. It was first recognised in Scotland in the early 1900s, yet relatively little is known about the condition.

Another name for the condition is equine disautonomia, so-called because it is a disease in which degenerative changes occur in the central nervous system and to the nerves of the autonomic (involuntary) nervous system. This results in malfunction of the whole digestive system.

The United Kingdom has the highest incidence of grass sickness in the world with cases being more common in spring. Young adult horses, aged between two and seven years, appear to be at the highest risk of the condition, but it can affect horses of any age.

With more horses being turned out at grass currently due to the Covid-19 restrictions, all owners should be aware of the signs and prepared to act promptly if they think their horse could be affected.

If you suspect your horse may be showing signs of grass sickness then a vet should be called immediately.

Grass sickness can be acute, subacute or chronic in nature. While around half of the chronic cases may recover with careful nursing, the more acute cases will not survive and are normally put down on welfare grounds. If acute cases are not euthanised, death often occurs within 48hrs of the onset of clinical signs.

Grass sickness: which horses are at highest risk?

• Horses between the ages of two and seven in good to fat body condition are at the highest risk, although equine of all types and ages can be affected
• It is particularly prevalent during April, May and June, and later in the autumn, after a spurt of grass growth, but can occur at any time
• Anecdotally, ground frosts and sudden weather changes are associated with disease outbreaks
• There is evidence that the majority of cases occurred during periods of cold, dry weather
• Equine grass sickness almost exclusively affects grazing animals. Risks include dietary changes, recent movement to new premises or pasture and frequent administration of wormers
• If your horse is kept in a high-risk area, always consult your vet before choosing a worming treatment
• Moderate worm egg counts have been associated with decreased risk of the condition
• Frequent grass cutting and manual faeces removal appear to lessen the likelihood, but pasture disturbance, such as construction work, for example replacing fencing, digging ditched or even large numbers of mole hills, may increase the risk
• Cases are more common on previously affected premises and pastures, and at large establishments such as livery yards, riding schools and stud farms
• Grazing with high soil nitrogen and sand or loam soil types have been found at affected locations
• There is some evidence that premises with domesticated birds or fowl may carry a heightened risk
• Survival rates from chronic grass sickness are greater in Scotland (60%) than in England (45%), but the reasons for this are not yet known. Equally strangely, grass sickness has not been found in Ireland, which has a somewhat similar climate

What are the signs of grass sickness?

Grass sickness has acute, subacute and chronic forms.

In acute grass sickness cases, the signs are suddenly and severe. They include colic, reflux of green stomach fluid down the nose, difficulty in swallowing, muscle tremors, abnormal sweating patterns, impaired gut activity and impaction of the colon with depression and distress.Horses suffering the subacute form will have milder signs than are seen in acute cases. Most subacute cases will require euthanasia if they are unable to swallow, but some will progress to the chronic form.In chronic grass sickness cases (typically horses that are still alive eight or more days after first showing signs), the signs develop more slowly and include marked weight loss, variable difficulty in swallowing and abdominal discomfort, muscle tremors, sweating, slow gut activity and a “snuffling” sound during breathing, due to blockage of the nasal passages with mucus. Some success can be achieved in treating this form of the disease with very intensive nursing over a long period of time.

How is it diagnosed?

While vets will diagnose the majority of horses with grass sickness based on clinical signs, the best way to definitively diagnose the disease in a live horse is to take a biopsy from the intestine while the horse is under a general anaesthetic. This is obviously very invasive, so recent research has looked at alternative biopsy sites, such as evaluating rectal biopsies¹.

There are other helpful tests that can provide a guide, such as applying phenylephrine eye drops to the conjunctiva of one eye – if the eyelid of the treated eye becomes less droopy 30minutes later, this increases the suspicion that the horse may be suffering from grass sickness.

The Animal Health Trust launched a major nationwide blind trial of a vaccine for grass sickness in 2014 involving more than 1,000 equines across a two-year period. The results of the trial have not been released.

Treatment for grass sickness

Horses suffering from acute signs of grass sickness cannot be saved and should be euthanised on welfare grounds as soon as the diagnosis is clear. Most subacute cases also require euthanasia if they are unable to swallow. It can be extremely difficult for all concerned to make the decision, but the important thing is to ensure the horse does not suffer and discuss with your vet.

Treatment for chronic grass sickness cases is extremely onerous, time-consuming and emotionally taxing, according to the Dr E Milne of the Equine Grass Sickness Fund², who warns that even with the most dedicated nursing, many horses cannot be saved. Careful selection of appropriate horses for treatment is important. This should include willingness and ability to attempt to drink and swallow feed and the absence of continuous colic pain. The greatest obstacle to a good outcome is the profound lack of appetite that is commonly seen in many cases of grass sickness.

Consequently a highly palatable feed that is high in energy and protein and is easily swallowed should be fed. Small appetising feeds should be offered at least four to five time a daily. Fresh water should always be available.

Initially, horses should be kept stabled in a deep straw-bedded box, but short walks in hand two or three times a day are important to help stimulate the movement of the horse’s gut and to help keep the horse’s interest.

As a chronic case improves, the horse can turned out on good grazing, starting with 20-30min and gradually increasing.

Vets usually give horses with grass sickness pain relief, or use appetite stimulants to encourage them to eat.

Many horses with chronic grass sickness have a low body temperature, so are best kept warm in a thick wicking rug that allows sweat to evaporate while maintaining body temperature.

Potential complications include diarrhoea, choke and inhalation pneumonia. If the horse avoids these and other challenges, gradually weight gain can be expected three to five weeks from the onset on the disease. Return to full weight can take months and will never be achieved in some cases. Unusual sweating and problems with swallowing should also gradually improve.

If the horse is doing well six to eight weeks after first succumbing, the chances of survival are good. The recovery rate in chronic cases is around 50%.

What causes grass sickness?

It has been believed that a toxin produced by the bacterium Clostridium botulinum causes damage to parts of the nervous system, which control involuntary functions, producing the main symptom of gut paralysis.

However, this was questioned by recent research published in the Equine Veterinary Journal (October 2016)³ that identified key differences between grass sickness and botulism. The study suggests that grass sickness is unlikely to be caused by neurotoxins from this bacterium and concludes that further investigation of an alternative cause is needed.

The high levels of the condition in Scotland may be partly associated with the particular composition of macro and trace elements in the soil in this region, according to another study published in the Equine Veterinary Journal (October 2016)⁴.

Prevention

It may help to keep horses indoors for at least part of every day, and/or feed supplementary roughage during periods of peak incidence. It is thought it may be more of a problem in areas where the grazing is sparse. It therefore makes sense to provide additional nutrition or bring horses in some of the day when the grazing is poor, especially with young or newly arrived horses, or those on grazing where a case of grass sickness has already occurred. If there is an option to do so, it is best to move horses off grazing paddocks where grass sickness is a known concern.

There are some suggestions that mixed grazing with sheep or cattle may reduce the risk, which also may help paracite control. In high-risk areas, it may make sense to removed droppings from pasture by hand, rather than using mechanical devices. Overall anything that minimises stress of horses in high-risk areas is likely to beneficial.

In November 2019 the disappointing news was released that a four-year field trial of a vaccine, which it was hoped would be effective in preventing grass sickness, had proved inconclusive⁵, so currently there is no vaccine available. The nationwide research had involved more than 1,000 horses and ponies at 120 premises.

References

1: Histological assessment of β-amyloid precursor protein immunolabelled rectal biopsies aids diagnosis of equine grass sickness

2: Management of Chronic Grass Sickness Patients

3: Equine grass sickness, but not botulism, causes autonomic and enteric neurodegeneration and increases soluble N-ethylmaleimide-sensitive factor attachment receptor protein expression within neuronal perikarya

4: Equine grass sickness in Scotland: A case-control study of environmental geochemical risk factors

5:

Also: Equine grass sickness

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A gelding who “never gave up” and survived grass sickness has delighted his owner by returning to ridden work seven months later.

Newcastle-based Julia Wood’s 16.1hh gelding Muddy was taken to the Dick Vet Equine Hospital, Edinburgh, on 9 September last year.

“Muddy had come in from the field and I noticed he was sweating between his front legs and had a twitch at his hindquarters so I rang the vet,” Julia told H&H.

“For a few days before he had appeared well in himself, but had been leaving some hay in his stable and his bed had been cleaner with less droppings so I was worried he could have an impaction.”

Julia said after vet examination it was agreed 11-year-old Muddy should be taken to the local animal hospital for further testing.

“His heart rate was up and by the time he arrived at the hospital he was dripping with sweat,” she said.

“The vet said they would do some tests and I received updates every couple of hours. They said Muddy had good gut sounds so at the time they weren’t convinced it was grass sickness.”

Grass sickness is an often-fatal condition that typically occurs in grazing horses. It can be acute, subacute or chronic in nature. While around half of the chronic cases may recover with careful nursing, acute cases are normally put down on welfare grounds. If acute cases are not euthanised, death often occurs within 48hrs of the onset of clinical signs.

Julia said she received a further update at 12.30am to say Muddy’s condition had deteriorated and he needed to be transferred to the Dick Vet.

“The vet said they now suspected it was grass sickness,” she said. “My big concern was whether he would be fit enough to travel as I didn’t want to put him through a three-hour journey if he wasn’t.

“My husband Perry and I collected him and began the journey. I remember every time we went through a village with street lights, Muddy would whinny so I knew he was ok.”

Muddy was taken for emergency treatment on his arrival at the Dick Vet.

“By 6.30am the vets said it was looking very likely to be grass sickness, but there is no test to confirm it,” said Julia.

“At that point it was touch and go – it was awful. I was told the next seven days would determine if it was a sub-acute or chronic case.”

Muddy spent three weeks at the hospital receiving round-the-clock nursing.

“He would gain weight, and then lose it again and have good and bad days. He was being hand-fed and it was all about trying to get him to eat,” she said.

“On 30 September he had stabilised and was well enough to come home. The vets said they hadn’t had a horse turn around as quickly as Muddy had in such a long time.”

Julia said Muddy continued on his road to recovery, being fed four times a day, and by November he showed signs of being on an “upwards curve”.

“It was a case of keeping him eating,” said Julia. “After trying lots of different things he began consistently eating soaked grass pellets and from there his grazing and haylage intake increased from then. The Equine Grass Sickness Fund charity and the Dick Vet hospital were amazing resources and provided so much support.

“It was an awful time but he never gave up – and we never gave up. He’s such a people horse and I think it’s what helped him get through.”

After receiving vet approval, Muddy returned to exercise at the beginning of March.

“It was really emotional getting back on. He was so responsive and seemed so happy,” she said.

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Julia has urged other owners to get to know what is normal for their horses and to be aware of grass sickness signs.

“Muddy had seemed well in himself in the days leading up to the day apart from his stable being cleaner, until I found him sweating,” she said.

“People should look out for signs and if they’re ever concerned get in touch with their vet straight away.”

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Why would one horse develop equine grass sickness (EGS) and not another? Owners who have nursed an animal through this debilitating disease — or lost one to it — are left puzzling over what they could have done to prevent it.

Sadly, there are still no answers. A vaccine trial has proved inconclusive and the cause of EGS remains a mystery. So what do we know about this troubling condition — and where, exactly, do we stand?

Risk factors

“EGS is a degenerative disease of the nervous system that affects horses, ponies and donkeys, resulting in impaired motility of the gut,” explains Dr Tim Mair MRCVS. “Clinical signs vary, depending on how much nerve damage has occurred.

“Less extensive damage results in a milder form of the disease called chronic EGS,” he adds. “Greater damage results in permanent paralysis of the gut and severe clinical signs, and is termed acute or sub-acute EGS. While a proportion of animals affected by chronic EGS can survive, the disease is always fatal in its acute and sub-acute forms.

“All ages are at risk, but especially young horses with access to pasture in springtime,” says Tim, adding that the highest incidence occurs in animals between two and seven years old. “It is most common between April and July, with a peak in May and a second, smaller peak in autumn.

“Many potential causes have been considered, including poisonous plants, chemicals, bacteria, viruses and moulds,” says Tim. “A favoured theory is that EGS is associated with intestinal overgrowth of a toxic soil-associated bacterium (C. botulinum), which damages nerve cells in the digestive tract.”

While EGS occurs in most areas of the UK, eastern counties are considered particularly at risk. Certain paddocks are thought to be hotspots for the disease, with cases occurring in consecutive years — for no known reason.

“Research has identified a number of factors that increase the risk of the disease,” explains Tim. “These include recent pasture changes or disturbance, such as construction or harrowing, and sites where there has been an outbreak previously.

“Studies indicate that EGS is non-contagious,” he adds. “It is more likely to reoccur where there are a high number of horses, especially young animals.”

Intensive care

With so little scientific evidence to work with, experts are hard-pressed to offer advice about preventative measures — although precautions can be taken.

“Stabling animals 24/7 during spring and early summer will reduce risk, especially when dry weather with a temperature of 7-11˚C has persisted for 10 consecutive days,” says Tim. “It is also advisable to stable horses new to premises where the disease is known to occur for two weeks, before introducing grazing slowly.

“If a case occurs among a group of horses, it is best to move the others out of that field.”

While there is no specific treatment for EGS, chronic cases benefit from intensive nursing.

“Those affected by acute and sub-acute EGS cannot survive and should be euthanised,” says Tim. “Once clinical signs are apparent, the nerves will be permanently affected. In chronic cases, however, the damage is relatively mild and the remaining nerves may be able to compensate.

“Treatment should only be attempted if the horse is not in pain, is still able to eat and is interested in life,” he adds. “Constant nursing care and human contact are vital, along with the provision of palatable, high-energy and easily swallowed food. With such intensive management, around 70% of treated cases can survive.”

Focus on fungi

The recent nationwide field trial for a vaccine for the prevention of EGS involved more than 1,000 animals residing at 120 premises across the UK which had been previously affected by a high incidence of the disease.

The study was co-ordinated by the Animal Health Trust, in collaboration with key university veterinary schools and support from the Moredun Foundation Equine Grass Sickness Fund. Sadly, the trial did not show a significant protective effect of the C. botulinum type C vaccine.

So what’s the next step?

“Our current focus is to test the theory that EGS is caused by a toxin produced by one or more of the numerous fungi growing on pastures,” says Professor Bruce McGorum FRCVS of the University of Edinburgh. “Many risk factors for EGS are consistent with involvement of such a fungal toxin, including the seasonal occurrence, the clustering of cases in certain locations and the climatic conditions that often precede the development of cases.

“This research follows work from the 1990s, which identified increased numbers of particular fungi on grasses from EGS fields and within the intestine of EGS horses. The potential for this previous work to identify a fungal cause was likely hampered by the limited laboratory tools available.

“Within our current three-year project, funded by the Horse Trust, we are adopting a more sensitive genomic approach which allows the detection and identification of thousands of different types of fungi within the intestinal tracts of EGS and healthy horses, thus permitting comparisons to be made,” adds Bruce. “It is hoped this comparative genomic approach might increase the chance of finding the elusive ‘needle in the haystack’ that causes this devastating disease.”

‘I never thought it would happen to me’

“I didn’t put two and two together,” says Felice Chilcott of the early signs in 2015 that her six-year-old warmblood gelding Jaguar (Jack) had developed chronic EGS. “He was always quite a ‘hot’ chestnut, but that didn’t explain him coming in on a cold day in a sweat. When he started picking at his feed, I thought he must be eating more grass.

“The day he started trembling, the vet identified Jack’s drooping eyelids and almost instantly suspected EGS. I felt as if I’d been pushed off a cliff.”

With support from the Royal (Dick) School of Veterinary Studies, Felice nursed him through the nightmare months ahead.

“They said he would be better at home, as the trauma of a journey would potentially set him back,” she says. “I had to feed him every four hours, encouraging him to eat anything I could. We worked our way through all sorts — haynets of strimmed grass, windfall apples — everything well-soaked as he wouldn’t eat anything dry.

“He became painfully thin and looked so miserable, standing at the back of his stable with his head down,” adds Felice. “I thought he would die. When I realised he might survive, I wondered if he’d ever be strong again.”

After months of round-the-clock feeding, Jack gradually gained weight and could return to light work. He is now winning at British Dressage elementary level, with Area Festival and Scottish national championship titles to his name.

“He is now healthy looking but will never be a good-doer,” says Felice. “What he went through is always at the back of my mind. We’re based south of Aberdeen — known as an EGS hotspot — but we have good, relatively old pasture that has been grazed by young horses with no problems,” she adds. “It’s still a puzzle.”

Ref Horse & Hound; 16 January 2020

A field trial for a new equine grass sickness vaccine has proved inconclusive.

The nationwide research involved more than 1,000 horses and ponies at 120 premises over four years, but has not resulted in conclusive proof that the vaccine prevents the devastating disease.

However, it has thrown up new information to help scientists gain a better understanding of the condition.

The trial aimed to determine the effectiveness of a Clostridium botulinum [C. botulinum] type C vaccination in preventing grass sickness, by comparing the number of cases in groups of vaccinated and placebo-treated equines.

Most vaccinated horses had a significant immune response and their C. botulinum type C anti-body levels after the primary course were on average 2.5 times higher than before the vaccines.

But the overall number of grass sickness cases over the trial, which ran from 2014 to 2018, was considerably lower than anticipated. Only nine cases were confirmed among the equines on the trial and the risk of grass sickness was not significantly reduced in those that received the vaccine compared to the placebo-treated group.

This meant it did not provide evidence that the vaccine helped prevent the disease.

“Although the field trial did not demonstrate a significant protective effect of the C. botulinum type C vaccine against equine grass sickness, this truly unique research has still achieved a number of things,” said Dr Richard Newton of the Animal Health Trust.

“We now have a greater understanding of equine grass sickness and the trial provided further evidence of vaccine safety under conditions of field use.”

Article continues below…

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Dr. Jo Ireland from the University of Liverpool added: “We are so grateful to all the veterinary practices, horse owners and supporters who helped make this research possible.

“The significant amount of data that has been collated during this nationwide field trial will be a very valuable resource for subsequent research studies to benefit future generations of horses and ponies.”

The trial was carried out as scientific evidence suggests that equine grass sickness may be associated with C botulinum type C, which is found commonly within soil.

As other, similar diseases such as tetanus and botulism can be prevented through vaccination, this would suggest the same may be true of equine grass sickness.

The field trial also found both the vaccine and placebo injections were safe, with a low frequency of local injection site reactions.

While findings of the effectiveness of the vaccine were inconclusive, researchers did find that both younger animals and low C. botulinum type C antibody levels were significantly associated with an increased risk of grass sickness.

It also made the groundbreaking discovery that low anti-body levels were found in equines affected by grass sickness before the onset of the disease.

It has also led to the conclusion that further research to fully explain the nature of the association between C. botulinum type C and EGS would be warranted.

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The owner of a pony whose weight dropped to 260kg as she nursed him through grass sickness said she never thought he would return to the show ring.

Amber Smalley’s now-eight-year-old 14hh cob Joey was diagnosed with the disease in May 2018.

“Joey had a biopsy to confirm the diagnosis and I was asked if I wanted him put down but I said no. He was my first horse and I didn’t want to let him go without trying,” Amber told H&H.

“He spent a week in hospital and when I got him home he had to be fed every hour by syringe. I was going to the yard four times a day, as well as friends going to help feed him.”

Over six months Joey’s condition improved and by November his weight had increased to 345kg.

“He was doing well but after new year, he got an infection and became very poorly again; discharge was coming out of his nose and he had a high temperature. We aren’t sure what caused it but he was given a course of antibiotics and after a few weeks he improved.

“I started riding him again in February and it was the best feeling I could ever have. When he was diagnosed I’d packed all my tack away and never expected to take it out again.”

Amber spent the summer working on Joey’s fitness and on 18 August they returned to competition at a Rochdale & District Riding Club show.

“I didn’t think we would be out again,” she said. “We did ridden cob, novice show cob and in-hand cob which he was fourth in. We weren’t placed in the ridden class but the judge said in six months’ time he’ll be winning classes.

“On 20 October we did the annual North West Championships show and made it through to the evening performance of the traditional ridden cob class. I’m so proud of him, I never thought we’d be doing anything like this again.”

Article continued below…

‘Don’t give up hope’ says owner of grass sickness survivor

Joey dropped to his lowest weight of 260kg from his original weight of 420kg

Group aims to rebuild after devastating loss of three horses to grass sickness

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Amber said Joey will need six-monthly vet check-ups but she is looking forward to a full show season next year and hopes to compete in dressage in the future.

“He is still quite lean and the vet said he might always look a bit underweight after what he went through. He needs to have sloppy feeds as he still struggles with swallowing but he is back to his cheeky self,” she said.

“During his illness I had times where I didn’t think he would make it but it feels like we’ve been given a fresh start. Nursing wasn’t an easy route and you’ve got to make sure it’s the right decision for the horse but I’m so glad we got through it. I hadn’t heard of grass sickness before he was diagnosed so I’m hoping to raise some more awareness of the disease and do some charity rides in the future for the Equine Grass Sickness fund.”

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By Emma Stenhouse

A Riding for the Disabled Association (RDA) branch that suffered the “devastating” loss of three horses to grass sickness is hoping to expand its herd and get back on track.

The West Lothian branch, which had catered for some 60 adults and children, lost eight-year-old Jack, seven-year-old Rosie and three-year-old mule Daisy from its herd within three days in May.

“The loss was devastating to everyone in our group, and just so unexpected,” group chairman Neil McIntosh told H&H.

“Daisy had been born onsite and while not used for lessons yet? was much loved by all, and always protective of our young participants.

“Jack and Rosie had lovely natures and so many of our volunteers felt a special bond with them. Jack in particular was very chilled out and enjoyed cuddles from our volunteers and participants.”

The loss means the group cannot now provide as much riding as it would like.

Trustee Don Whyte said: “Two of the horses were our bigger ones, and this has meant a lot of our older riders have not been able to get out much this season.”

The charity usually manages to raise funds to cover its costs by running an annual fun day, but it is now considering a different approach.

“We are going to create a sub-committee whose job it will be to look at routes for us to bring in the money we need to get things up and running again,” added Don.

Ideas have so far involved a sponsored walk, a 50^th anniversary celebration for the RDA, and a Just Giving page.

The fundraising target is £8,000 which will cover buying new horses, loss of income and settling vet bills.

Because the group, run by an 80-strong volunteer team, only has access to an outdoor school, lessons tend to run from May to October. Over the winter, focus shifts to fundraising.

After the money is raised, comes the challenge of finding suitable horses. Don said: “We can’t just go out and get any old horse, it must be a specialist type with the right temperament.”

Neil said the aim is to be “fully back up and running for the 2020 season.”

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This is the first time the grazing used by the West Lothian RDA has been affected by grass sickness. The group is working with its vets to decide on the best management plan for the herd.

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A charity calendar starring some of The Queen’s Highland ponies will go on sale to raise funds for grass sickness.

Heald Town Highland Pony Stud, owned by Carolyn and Melody Ashcroft, is creating its annual charity calendar to raise funds for the Moredun Foundation Equine Grass Sickness Fund, for which it raised £1,500 last year.

Melody, who took the photographs for the calendar, told H&H: “We started the calendar five years ago and have previously supported other animal charities. I work with the Highland Pony Enthusiasts Club and grass sickness is something we are very passionate about so we decided to support it last year.”

Two months of the calendar will feature photographs of the Queen’s Highland ponies from Balmoral Estate, managed by Sylvia Ormiston. The estate lost two stallions in May 2018 to grass sickness; four-year-old Balmoral Lord and five-year-old Balmoral Hercules.

“One of our former ponies, Heald Town Bonny owned by Mr and Mrs McMillan, went to Balmoral to be covered by Balmoral Lord but he came down with grass sickness before covering her. She was instead covered by Balmoral Hercules only for him to sadly come down with grass sickness days later,” said Melody.

“Sylvia is very passionate about the breed and to be able to photograph the ponies at Balmoral was really lovely. The temperaments of the Balmoral ponies were absolutely impeccable.”

Sylvia told H&H the Queen’s ponies featuring in the calendar was a “fitting tribute” to Lord and Hercules.

“The calendar is for a tremendous cause. We lost Lord and Hercules within a fortnight of each other; they were our working breeding stallions – in one swoop we lost our 10-year breeding plan. It doesn’t matter who you are, the disease can affect you,” she said.

“Lord and Hercules’ legacy will continue through their youngstock. They were in the process of breeding last year when we lost them so luckily we have a Lord filly and two Hercules colts born this year. We’re very lucky to have their children.”

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Melody added the disease is very close to her heart after the loss of one of Heald Town Highland Pony Stud’s homebred ponies, Heald Town Drumlin owned by Samantha Kay, this year.

“It is such a horrible disease, we need to do as much as we can to help raise awareness. We want to shout about it from the rooftops and encourage people to raise funds for the charity,” said Melody.

The calendars will cost £12 and will also feature ponies from the stud. Fans can vote on which pictures will be included by voting on the stud’s Facebook page. Voting runs from 1 August until mid-September and the calendars will be available to buy from 1 October.

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The owner of a horse who was put down after he collapsed from grass sickness wants others to support the “incredible” fire and rescue service who tried to save him.

Dayna Potter and her family found homebred 16hh four-year-old gelding Mouse down in the stable at their farm on Sunday evening (31 March).

Dayna told H&H: “Mouse had been losing weight which was really unlike him. He went downhill last Thursday (28 March) and the vet diagnosed grass sickness.

“On Sunday he had a good day and looked on the up. We were checking him every two hours but when we went to check him at 8pm he’d gone down. He kept trying to get up, it was like he knew he had to, but he couldn’t – it was heartbreaking.

“He got himself stuck in the stable but we managed to get him turned round with ratchet straps round his legs, then he got himself out of the stable.”

Dayna contacted her vet and Surrey Fire and Rescue Service.

“We knew we weren’t going to get him up on our own and would need the fire brigade,” said Dayna. “We hoped his legs had just gone numb from being down for so long and he would be ok once he was up.

“The local team from Farnham fire station arrived first at 11.30pm and then crew from Painhill arrived with the crane to pick him up. The vet sedated him and the fire brigade got him back up on his feet.”

Dayna said the fire crew waited with Mouse to make sure he was ok.

“Everyone was cheering that we had got him up and he seemed fine. They left him in the straps for a while to regain himself and once he seemed to be holding himself up ok one of the crew walked him round,” she said.

“The vet had checked him over and he had an appetite and was eating carrots. I went home but my mum phoned to say he had gone down again so I rushed back to the farm and we decided we had to call it a day and he was put to sleep.”

Dayna wants others to support Surrey Fire and Rescue Service, which is going through a consultation period, and may have to introduce charges for large animal rescue in the future as part of the Making Surrey Safer Plan 2020-2023.

“I could tell from the minute the crew arrived they were going to put their heart and soul into saving Mouse – they were so invested. They were the only ones who could keep us calm and told us not to worry, they were so positive and you could really see the crew cared about Mouse,” said Dayna.

“I saw the H&H story a few weeks ago about the Surrey Fire and Rescue Service consultation and that we might have to pay for animal rescue and I want to show my thanks and appreciation to the fire service by raising awareness of the incredible job they do.”

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Owners have until 26 May to share their views on the consultation by completing an online survey.

“I don’t want sympathy, but if any positive can come out of this horrendous situation I want the fire service animal rescue unit to be supported,” said Dayna.

“If the service becomes chargeable it could put people off calling them out. I don’t want anyone to be in the situation I was in and not call the fire brigade because they either can’t afford it or one day it’s not there.”

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An owner whose pony survived a severe bout of grass sickness wants to inspire others in a similar situation not to give up hope.

Amber Smalley’s seven-year-old 14hh cob Joey, who she has owned since he was three, was diagnosed with grass sickness on 11 May.

Grass sickness is an often fatal condition that typically occurs in grazing horses. It was first recognised in eastern Scotland in 1907, yet relatively little is known about the condition.

Amber told H&H: “It came on suddenly. Joey had came in from field and we thought he had colic, there was nothing to say running up to that day anything was going to happen.

“My vet came out and made the grass sickness diagnosis because his heart rate was so high.”

Joey was taken to Leahurst Equine Practice in Liverpool where he had a biopsy to confirm the diagnosis.

“The vet said he probably wouldn’t survive, the results of the biopsy were quite severe. I was given the option to put him down then or see how he got on – every day I thought he was going to go,” said Amber.

“After a week the vet said I could take him home and try to nurse him. He had to be fed every hour by syringe, it took all of my time but I had a lot of help from friends going to the yard to feed him for me.”

In mid-July Joey dropped to his lowest weight of 260kg from his original weight of 420kg.

“I had a little bit of doubt about his future but you could see he still wanted to live and he was still managing to eat. He wasn’t having any organ failure so we carried on,” said Amber. “He’s quite a cheeky pony, he stayed bright through most of it but did have some days he didn’t want to walk out.”

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Amber said she was “very grateful” for the quick diagnosis by the vets and that Joey has since made a full recovery.

“He has just had another check-up and he now weighs 345kg. He still has weight to put back on but I’ve been told we can start riding again. I hope one day we can get back out showing,” said Amber.

“You hear so many sad cases of grass sickness but I want people to hear a positive story. Don’t give up hope, even if they eat anything, that’s a good result.”

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An owner whose pony recently recovered from equine grass sickness (EGS) is warning others to watch out for signs of the often-fatal condition.

Caroline Casey of north Scotland bought Summer for her then three-year-old daughter, Jorgi, in August 2014.

Summer temporarily moved yards for two weeks in May last year.

Upon returning to the original yard, the palomino was taken to a Pony Club rally where Caroline noticed she was shaking intermittently and foaming at the mouth.

When Summer returned from the rally her shaking became worse.

Caroline called out her vet who diagnosed grass sickness.

“My heart sank, I was heartbroken thinking this was the end,” she said.

Caroline brought Summer in at night to monitor what she was eating and she gradually improved with careful management.

Seven-and-a-half weeks later, she stopped displaying the signs of the condition.

She was brought back into work in September and since then she has enjoyed local shows and Pony Club rallies with Jorgi, who is now five.

“We are extremely lucky to still have her, she is worth her weight in gold,” added Caroline.

EGS is an often-fatal condition that is most prevalent between April and September.

The condition causes damage to parts of the nervous system that control involuntary functions, producing the main symptom of gut paralysis.

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It is most frequently seen in horses aged between two and seven, and signs include patchy sweating, shivering, constipation, reflux of fluid from the nose and rapid weight loss.

The condition is thought to be caused by a toxin produced by clostridia bacteria.

For more information visit www.grasssickness.org.uk

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Similarities between the signs of equine grass sickness (EGS) in horses and Alzheimer’s in humans have been found in a ground-breaking study.

Researchers from the University of Edinburgh’s Roslin Institute and Royal (Dick) School of Veterinary Studies were hoping to find out more about the causes of EGS when they made the discovery.

They looked at nerve tissue from six horses that had died from the condition and found that it contained proteins commonly seen in the brains of Alzheimer’s patients.

“This is the first study to show similarities between an apparently unrelated neurodegenerative disease of large animals and human neurological conditions,” said Dr Tom Wishart from the Roslin Institute, co-leader of the study.

“Although the causes of these conditions are unlikely to be shared, the findings suggest that similar mechanisms could be involved in the later stages of disease.”

In total, 506 different proteins were found to be altered in nerve tissue from horses with EGS compared to those that had died from other causes.

Prof Bruce McGorum, who led the study, told H&H that they are still trying to find the cause of EGS.

He added that he is hopeful that data from the study can be used to develop a non-invasive test to accurately diagnose EGS before death, as this is often challenging.

Earlier this year, H&H reported on a rise in the number of EGS cases (news, 14 May).

The often fatal condition attacks nerve cells in horses and relatively little is known about it.

There are three types of the disease: acute (sudden on-set with colic-like signs), sub-acute (similar but less severe) and chronic.

Signs include abdominal pain, poor appetite, patchy sweating, increased heart rate and saliva, dribbling and depression.

It is most prevalent from April to September

A spokesman for The Equine Grass Sickness Fund, who funded the study, said that this is an exciting project as it ventures into “uncharted territory”.

“Although it does not help identify the cause of the disease, it furthers our understanding of the changes that take place within the horse,” he told H&H.

“If it helps lead to a non-invasive method of diagnosis in the live horse, that would be a major step forward.”

The results of the study were published in the journal Molecular and Cellular Proteomics on 13 September.

Ref: H&H 15 October, 2015

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A rescue pony who survived grass sickness has been crowned supreme champion in World Horse Welfare’s rehomed horse of the year awards.

Piebald gelding Hercules arrived at the charity’s Glenda Spooner Farm in Somerset in 2011 with chronic grass sickness.

Vets gave him just a 2% chance of survival but following care from World Horse Welfare staff he made a full recovery.

He was rehomed as a three-year-old to Alison Ironside, who continued his education before backing him to ride.

“In March 2014 I was diagnosed with breast cancer and after various surgeries, treatments, drugs, plus many months sat in a chair I decided that it was time I started riding again,” said Ms Ironside.

“Out of all my ponies I knew that Hercules was the one I could trust to look after me in my very weak state. In true caring fashion, even at his young age, Hercules seemed to understand the situation — patiently and carefully carrying me around the lanes never putting a foot wrong.

“He is a pony that took a lot to save but he is a pony that has given everything he can back.”

Olympic gold-medallist Jane Holderness-Roddam

awarded Hercules the top spot in the awards’ faithful friend category.

“Hercules appeared to recognise and respond to his owner’s needs when she was ill and curtailed his natural exuberance throughout her rehabilitation,” said Jane. “This inbuilt sensitivity shows true friendship.”

Hercules was also chosen to receive the supreme champion accolade by World Horse Welfare’s chief executive, Roly Owers.

“Their bond of trust epitomises the close relationship between horse and owner. While we had so many fantastic entries, I feel that Hercules has well and truly earned his supreme champion award,” said Roly.

Celebrating rescue horses and ponies

World Horse Welfare invited nominations from its 1,700 horses and ponies currently out in homes. Three categories were open for entries, including funniest anecdote and biggest achievement, as well as faithful friend.

The winner of the funniest anecdote category was Wally, thanks to his tendencies of stealing his rehomer’s walking stick, grinning for a peppermint and peeing on command.

“I just loved the images of Wally peeing on command, and removing dad’s walking stick,” said Olympic dressage rider Richard Davison, who crowned Wally the winner.

“It must be chaotic ensuring Wally pees precisely on cue, while Dad is sending Maydays from halfway down the field because his walking stick has been removed. What must the neighbours think?”

The winner of the biggest achievement category was family pony Su, who has given 16 years of service to the Riding for the Disabled Association (RDA).

“In the end, Su pipped it for me because she has clearly helped so many people through her long experience at the RDA, and that kind of life-changing achievement may not be recognised elsewhere,” said Olympic eventer and World Horse Welfare patron Pippa Funnell, who chose Su as the winner.

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An owner whose horse survived equine grass sickness is raising awareness of the often-fatal condition.

Yvonne Maclean’s 17hh Hanoverian gelding, Malbec, was diagnosed with grass sickness last August.

His weight dropped from 750kg to 596kg in just six weeks.

“It was horrendous,” Ms Maclean told H&H.

“He wouldn’t eat at all — we were syringe feeding him every hour for the first two-and-a-half weeks.

“He was very unwell for 14 weeks and we were unsure if he would survive.”

The then five-year-old gelding’s condition gradually improved and he has made a full recovery.

Ms Maclean, who is based in the Scottish Highlands, wanted to raise money for the Equine Grass Sickness Fund (EGSF) and organised a show, which took place last month (22 August).

The show included showjumping, showing, mounted games and fancy dress classes.

Local people and businesses donated trophies and raffle prizes for the show and talks on equine grass sickness and laminitis were given by Ross-shire vet Douglas Swaffield.

More than 100 combinations took part and over £5,200 was raised for the charity.

Ms Maclean also aims to raise awareness of the equine grass sickness vaccine trial.

A rider at the show, who is currently nursing a two-year-old filly through grass sickness, signed up 10 horses for the trial, which is being conducted by the Animal Health Trust.

“I have been overwhelmed by the support we have had,” added Ms Maclean.

“We have decided to make this an annual event due to so many people wanting to get involved.”

A rise in cases of grass sickness

Earlier this year H&H reported on a rise in the number of cases of grass sickness.

There is relatively little known about the condition, however, it is most prevalent from April until September.

Vets believe grass sickness is caused by a toxin produced by clostridia bacteria, the same bacteria that, in different circumstances, can cause botulism. They affect the nervous system.

Signs of the condition include abdominal pain, poor appetite, patchy sweating, increased heart rate, increased saliva and depression.

For more information visit: https://www.justgiving.com/Yvonne-Maclea

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A rider is urging other horse owners to be aware of the signs of equine grass sickness after her horse survived the often-fatal condition.

Mandy Halliday from Beccles, Suffolk, told H&H that her horse Thor, a seven-year-old Appaloosa, is still recovering 12 weeks later (not pictured).

“He’s a bit brighter and he’s gaining weight,” she added.

However, Ms Halliday wants more people to know about EGS.

“Like many people I’d heard of it, but I didn’t really know much about it,” she said.

“I’d like other owners to be more aware of the signs so they can catch it and hopefully their horses will survive too.”

She told H&H that she had come home from work earlier this year to find Thor “a bit off colour”.

“He wasn’t himself,” she said. “The next day he was more sombre and laying down. The vet came and diagnosed him with EGS”.

Thor then spent nine days in intensive care at Rossdales in Newmarket.

“It was so hard to see, and he was very depressed,” she added.

Ms Halliday has owned Thor since last August. The other animal on the land, a miniature pony, was unaffected.

There is relatively little known about the condition, however, it is most prevalent in April until September.

Earlier this year H&H reported a rise in the number of cases of EGS.

Vets believe EGS is caused by a toxin produced by clostridia bacteria, the same bacteria that, in different circumstances, can cause botulism. They affect the nervous system.

To try to avoid the condition owners are warned not to change field management or diet during the high-risk time.

Feeding haylage or hay at pasture, or bringing horses into a stable at night may reduce its occurrence as it cuts down on grazing exposure.

There are three types of the condition: acute (sudden on-set with colic-like signs), sub-acute (similar but less severe), and chronic (which accounts for around one-third of cases).

Signs include:

• Abdominal pain
• Poor appetite
• Patchy sweating
• Increased heart rate
• Increased saliva, dribbling
• Depression

The Animal Health Trust is currently putting out a final plea for owners whose horses have suffered EGS to come forward for a vaccine trial.

Owners who keep horses or ponies on premises that has had a case of EGS in the previous three years should register to take part in the trial by the end of August.

For more information visit: www.grasssickness.org.uk

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A pony who survived acute equine grass sickness (EGS) has completed a 300-mile trek across Scotland.

Candyfloss, her owner Leanne McDonald, terrier Foxy and stablemate miniature Shetland Tinkerbelle, completed their mammoth journey at the Royal (Dick) School of Veterinary Studies in Edinburgh on 22 June.

There they met vet Dr Scott Pirie, who had liaised with Leanne about Candyfloss’ condition when the 13hh coloured fell cross cob mare was taken ill with EGS in 2013.

Also joining the team for the final day of the trek was another EGS survivor, Eva, who had been treated at the veterinary centre.

On the penultimate day of their journey, the walkers led a parade of equine survivors and owners whose horses had died from the condition at the Royal Highland Show (21 June).

Candyfloss also wore a remembrance ribbon and rosette bearing names of horses and ponies that had died.

Leanne told H&H she wanted to do something that was going to spread awareness about EGS and the money they raised was an “additional bonus”.

So far, their JustGiving page has more than £3,250 in donations for the Equine Grass Sickness Fund.

“I can’t tell you how proud I am of the ponies. They have both completed it amazingly well,” said Leanne.

“I am just in awe of the pair of them to be honest.”

EGS is fatal in 95% of cases and is most prevalent between April and September, especially in Scotland.

Candyfloss was diagnosed with acute equine grass sickness in June 2013 and made a full recovery.

Leanne consulted vets before setting out on the trip and kept the distances to between 10-15 miles a day on the month-long adventure.

“It was important to me that Candyfloss enjoyed it as much as I did,” she said.

“Every day was different, every day was a new adventure.

“We shared the whole experience together – the sunsets, the sunrises and the horrible weather and the sunshine.

“We saw some amazing parts of Scotland while we were walking and met some amazing people.

“Everybody has just been so nice and so kind.”

She added the whole thing was incredible and she “cannot thank everybody enough”.

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A pony that defied the odds and survived a life-threatening condition is taking part in a 300-mile trek.

Candyfloss was diagnosed with acute equine grass sickness (EGS) in June 2013 and has since made a full recovery.

Grass sickness is fatal in 95% and is most prevalent between April and September, especially in Scotland.

The six-year-old mare accompanied by her owner, Leanne MacDonald, set off from her home in Spey Bay, Moray, on 23 May.

The 13hh fell cross cob is also joined by her stable companion Tinkerbelle, a miniature Shetland, and terrier Foxy.

The team is hoping to raise awareness of the condition and money for the Equine Grass Sickness Fund.

Their route is set to take them to the Royal Highland Show on 21 June, where Candyfloss will lead a parade of survivors.

It is set to finish the following day at the Royal (Dick) School of Veterinary Studies in Edinburgh.

Candyfloss’ adventure has not been without drama.

As they crossed the Cairngorms, the path became increasingly steep and narrow.

The weather closed in and, being unsafe to continue, the trekkers climbed to 700ft and were rescued by Braemar Mountain Rescue.

Leanne spoke about why she decided to take on the walk.

“When EGS paralysis the gut you can see that they want to eat but they simply can’t,” she said.

“It is just such a horrendous thing to go through.”

Candyfloss suffered from weightloss, tremors, difficulty swallowing, sweating, loss of coordination and dropped six inches from her girth.

The trek is part of a series of fundraisers organized by Leanne and four other owners whose horses were affected by the disease – known as the Fabulous Five.

Last month H&H reported that vets were urging owners to be vigilant after a rise in cases of equine grass sickness (EGS) in the past year.

EGS is now thought to be caused by a toxin produced by clostridia bacteria, the same bacteria that, in different circumstances, can cause botulism. They affect the nervous system.

The Animal Health Trust is currently undertaking a trial of a vaccine for the condition.

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Vets are urging owners to be vigilant after a rise in cases of equine grass sickness (EGS) in the past year.

The condition — which is fatal in many cases — is most prevalent between April and September.

Last year insurers Petplan Equine paid out almost £37,000 in claims relating to the condition. The highest number of claims came in June and July — likely to have resulted from cases from May, which is recognised as a high-risk month.

EGS is now thought to be caused by a toxin produced by clostridia bacteria, the same bacteria that, in different circumstances, can cause botulism. They affect the nervous system.

“The bacterium lives in the soil and when it spreads onto the grass itself it can be ingested by horses,” said vet Gil Riley.

“The toxin that is produced by the bacterium after it has been consumed interferes with the nerves in the horse’s intestine, causing severe dysfunction and colic — which is almost always fatal.”

There are three types of the condition: acute (sudden on-set with colic-like signs), sub-acute (similar but less severe), and chronic (which accounts for around one-third of cases).

“Some cases of chronic EGS respond to intensive nursing and can survive. It is challenging to care for them properly. Often the biggest obstacle is their reluctance to eat, but it is very rewarding when treatment is successful,” said Dr Tim Mair from Bell Equine Veterinary Clinic in Kent.

He added that “this sort of intensive care is only appropriate for certain cases, which retain some ability to drink and swallow feed.”

To try to avoid the condition owners are warned not to change field management or diet during the high-risk time.

Feeding haylage or hay at pasture, or bringing horses into a stable at night may reduce its occurrence as it cuts down on grazing exposure.

A new vaccine trial for EGS is currently being conducted by the Animal Health Trust with the Universities of Edinburgh, Liverpool and Surrey, following around 1,000 horses and ponies for two years.

“We will record, review and compare incidence of EGS between the two groups [one given a vaccine, the other a placebo] to determine the efficacy of the vaccine,” said Dr Jo Ireland of the Animal Health Trust.

“If we see reduced disease incidence in vaccinated horses, this would provide a major breakthrough in the prevention of EGS.”

But many owners remain unaware of the condition.

Kate Thompson from the Equine Grass Sickness Fund said: “In the UK around 140 deaths from grass sickness are reported each year, but we believe the true number is much higher.”

“The statistics speak for themselves,” said Petplan Equine’s Charlotte Collyer.

“We understand an equine grass sickness vaccine is currently being trialled. Until then we want to remind horse owners that prevention is of paramount importance as this is a condition for which there is often no cure.”

For more information visit: www.horseandhound.co.uk/grass-sickness

Ref: H&H 13 May, 2015

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Equine Grass Sickness (EGS) is characterised by extensive nerve damage, which affects the gastrointestinal tract most severely. The disease remains a deadly enigma.

With no known cause, little by way of treatment available and an alarmingly high fatality rate (85%), the condition remains a major threat to the UK’s equine population.

In 2013, H&H first reported news of a nationwide EGS vaccine trial. One year on, how close are we to being able to protect our horses from this devastating disease?

Blaming bacteria

The idea of a vaccine came about following research carried out almost a century ago.

In the early 1900s, it was suggested there was a connection between EGS and Clostridium botulinum (C. botulinum) bacteria. These are commonly found in soil and are capable of producing a range of toxins, including those that damage the nervous system (neurotoxins).

The current theory is that type C of this bacterium causes EGS. It is thought the disease occurs when a combination of risk factors trigger bacteria already present within the horse’s intestinal tract to produce neurotoxins.

Horses with EGS have lower antibody levels to this type of bacteria, while those with higher levels have a reduced risk of the disease.

Additionally, horses that have been in contact with an EGS case appear less likely to develop the disease, suggesting they may have acquired some degree of immunity.

Pushing for a cure

Vaccines are used successfully to prevent other equine clostridial diseases, such as tetanus and botulism, and it is hoped vaccination may also help reduce the risk of EGS.

Vaccination field trials conducted in the 1920s found a significant reduction in the incidence of EGS in vaccinated animals, but unfortunately research was then directed away from the association between C. botulinum and EGS.

Ninety years later, the Animal Health Trust (AHT) has launched a groundbreaking trial for a potential vaccine, in collaboration with the EGS Fund and the universities of Edinburgh, Liverpool and Surrey.

The trial will determine whether vaccinating against C. botulinum type C can help to prevent EGS.

A field trial of this magnitude has never been undertaken in equine medicine. Consequently, several preliminary studies were completed to determine whether it would be feasible to conduct the study on a nationwide scale.

Pilot trial success

Initially, a small study was carried out to confirm the vaccine was safe for use in horses.

A feasibility study then surveyed horse owners and veterinary practices that had participated in the EGS surveillance scheme, identifying eligible premises and exploring opinions on participating in the trial. Three-quarters of owners responding to the survey said they would be willing to participate, while 99% of vets agreed to take part in the vaccine trial if one of their clients wished to enrol.

Finally, we undertook a successful pilot trial. This was designed to test the methods used in the vaccine trial, rather than to test the vaccine.

Ninety-five horses and ponies from EGS-affected premises were enrolled and assigned at random to receive a full course of either the C. botulinum type C vaccine or the inactive placebo injection. Both the vaccine and placebo were shown to be safe, with a low number of mild injection site reactions reported — none of which required veterinary attention or treatment.

Scientists in the AHT’s immunology group developed a blood test to measure equines’ antibody levels to C. botulinum type C, which was used to measure the immune response to the vaccination.

Animals in the vaccine treatment group were found to have substantial increases in their antibody levels, demonstrating that the majority receiving the vaccine had a significant immune response following their primary vaccination course.

The pilot trial provided a huge amount of valuable information and feedback, but the number of horses enrolled and the time for which they were followed was too small to determine whether the vaccine can prevent EGS. A nationwide trial was the vital next step.

Gathering evidence

The EGS vaccine trial began in March 2014. Recruitment is ongoing, the aim being to enrol 1,100 horses and ponies that will be followed for two years.

The trial design is based on protocols used for clinical trials in human medicine, ensuring the highest standards and attaining the best-quality evidence for the preventive effect of vaccination.

Once eligible horses and ponies are enrolled, they are randomly selected to join one of two groups of equal size — receiving either the C. botulinum type C vaccine or an inactive placebo injection. This “randomisation” ensures the only difference between the two groups is whether they receive the vaccine or the placebo.

To guarantee scientific validity, owners, vets and researchers will not be informed of the random group assignments until the end of the trial. This is commonly referred to as “blinding” or “masking”, and is vital to ensure the findings are not influenced in any way by the expectations of people taking part.

The number of EGS cases in the vaccinated and the placebo-treated groups will then be compared statistically to determine if vaccination against C. botulinum type C significantly reduces the risk of EGS.

It is rare for any vaccination to offer complete protection against a disease. Some animals’ immune systems respond less well to vaccination than others, meaning they may be less well protected.

It would therefore be expected that cases of EGS could occur in both groups throughout the trial. If the vaccine were effective in preventing the condition, however, the number of EGS cases in the vaccinated group would be significantly lower.

If shown to be effective, the vaccine would represent the first preventive healthcare measure to reduce the impact of this devastating disease.

This article was first published in Horse & Hound magazine (7 August 2014)

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Vets are warning that this winter’s extreme weather may be causing a rise in cases of equine grass sickness (EGS) after 2 horses died on Guernsey.

This is believed to be the first instance of the disease on the island, which has only around 750 horses.

The outbreak occurred at a single yard in February. A pony was also affected, but is recovering.

Guernsey vet David Chamberlain said the cases could be the result of excessive rain, which may have “triggered rapid grass growth, increasing the levels of causative bacteria in the horses’ gut”.

“This has been the wettest February in 35 years [and] the wettest winter in 101 years,” said Steve Byrne of the Guernsey Society for the Prevention of Cruelty to Animals, which is working with vets to advise owners.

The Animal Health Trust — which confirmed the Guernsey cases by laboratory analysis — told H&H that, while it has no records for Guernsey, numbers of cases across Britain are “a huge underestimate”. This is because EGS is not a notifiable disease and can only be confirmed by a post-mortem.

EGS is a neurological disease of unknown cause that paralyses the digestive system. More than 95% of cases are fatal.

It can occur in any breed of horse, usually 4- to 5-year-olds, and is almost exclusively found in grazing horses, but many owners are not aware of it (news, 25 July 2013).

“Surveillance shows there are around 140 cases per year, but as owners aren’t obliged to tell us, there are probably many more,” said the trust’s EGS research co-ordinator Jo Ireland.

“Anecdotally from vets, we understand there has been a rise in the UK this winter, but due to few people reporting it, we have no figures to back this up.”

The Equine Grass Sickness Fund’s Kate Thomson said that cases this year “have been as random as the weather, trickling on throughout the winter, rather than the usual May and September peaks”, although “hard evidence” is lacking.

Signs of grass sickness

• Abdominal pain
• Poor appetite
• Patchy sweating
• Increased heart rate
• Increased saliva, dribbling
• Depression

New trial of EGS vaccine

Horse owners are being encouraged to take part in a new vaccine trial for Equine Grass Sickness (EGS).

The trial will be conducted by the Animal Health Trust with the Universities of Edinburgh, Liverpool and Surrey and will follow 1,100 horses and ponies for 2 years.

There is growing scientific evidence to suggest that EGS may be caused by the bacterium Clostridium botulinum type C, which is found commonly within soil and is capable of producing a range of toxins.

Dr Jo Ireland said: “Half of the horses and ponies on the trial will be vaccinated with a C. botulinum type C toxoid vaccine; the other half of the horses and ponies will receive an inactive placebo injection. We will record, review and compare incidence of EGS between the 2 groups to determine the efficacy of the vaccine.

“If we see reduced disease incidence in vaccinated horses, this would provide a major breakthrough in the prevention of EGS.”

Only healthy horses and ponies with a valid passport kept on premises with a history of EGS cases in the past 2 years will be eligible.

To find out more about the vaccine trial visit: www.equinegrasssickness.co.uk or email equinegrasssickness@aht.org.uk.

This article was first published in Horse & Hound magazine (20 March 2014)

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For reasons no one really understands, Scotland has the highest prevalence of grass sickness in the world — especially in the east between Dumfries and Inverness.

It looks increasingly likely that the disease is caused by the same bacterium that causes botulism in other animals, although the mechanism by which the bacterial toxin affects the gut and nervous system is far from clear.

For years, vets have realised there must be certain factors associated with the disease, but trying to tie these down has been very difficult.

The biggest retrospective study of grass sickness cases in Scotland has just been published in the Equine Veterinary Journal (EVJ). It comprises a review of 455 cases of the disease, matched with 910 unaffected horses used as controls. All the horses were kept at grass in Scotland.

The details of the horses were recorded, together with their location and weather details at the time they became sick.

Statistical analysis showed some interesting risk factors. Scottish native breeds — the Clydesdale, Highland, Eriskay and Shetland — were more likely to suffer grass sickness than cross-breds or non-Scottish pure-breds. Disease prevalence increased towards the north.

Horses under two or more than 11 years old had a higher chance of contracting the disease, but there were no gender differences.

There appeared to be a firm link with some aspects of the weather, notably an increased incidence in areas where both minimum and maximum daily temperatures were lower and where there were more days of frost. There was a weaker association with increased hours of sunlight, but no link to rainfall.

The scientists speculate that there may be something in the way the grass grows during colder, brighter periods that increases the risk. There is, however, much work still to be done.

Horse owners are being warned to be extra vigilant about grass sickness this summer after reports of increased cases for this time of year.

The Equine Grass Sickness Fund (EGSF) told H&H it is receiving calls later than usual, due to the late spring.

“Usually we see a peak in May,” said Kate Thomson from the EGSF. “But this year we’ve had a boom in late June, early July. We’ve had about 10 calls in the past couple of weeks.”

Equine grass sickness is a neurological disease of unknown cause that paralyses the digestive system. More than 95% of cases are fatal.

It can occur in any breed of horse, usually 4-to 5-year-olds and is almost exclusively found in grazing horses.

“We are concerned that many people seem unaware,” added Ms Thomson. “In the UK around 140 deaths from grass sickness are reported each year, but we believe the true number is much higher.”

Alex Ferris-Drake, from West Yorkshire, lost her five-year-old Welsh Section D mare, Maggie, to the disease on 13 July.

“We had never heard of it until she got it, then 48hr later she was dead,” she said. “We need to spread the word.”

Signs are similar to colic and include sweating, a distended stomach and constipation.

“Preventative measures can be taken — ensure the horse has access to hay constantly, plus poo pick manually to make sure nothing disturbs the soil,” said Ms Thomson.

EGSF is appealing for funds to launch a nationwide vaccine trial. Visit: www.grasssickness.org.uk

This news story was first published in Horse & Hound magazine (25 July 2013)

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A hundred horses and ponies in the UK’s equine grass sickness hotspots will be vaccinated against the deadly disease this winter.

And a full trial of at least 1,000 horses and ponies is planned for 2013-14.

Equine grass sickness is a neurological disease of unknown cause that paralyses the digestive system.

Signs of acute grass sickness are similar to colic and include patchy sweating, a distended stomach and constipation or passing small, hard pellets.

The treatable, chronic version of the illness causes severe weight loss.

Dr Jo Ireland of the Animal Health Trust (AHT), which is running the trial with the Edinburgh and Liverpool veterinary schools, said: “This initial study will help us to ensure that the trial is practical to perform on a larger scale.”

In the first trial, 100 horses and ponies will receive four placebo or vaccine injections over a nine-month period.

The Equine Grass Sickness Fund then needs to raise £500,000 for the full trial.

The highest incidences of grass sickness occur on the east coast of the UK.

Kate Thomson from the fund said: “Around 140 deaths from grass sickness are reported each year, but we believe the true number is much higher.”

She said the vaccine trial is a chance to establish the believed link between the disease and the bacterium clostridium botulinum.

A vaccine for grass sickness was used in the 1920s, but fell out of favour.

For more information, go to www.grasssickness.org.uk.

This news story was first published in the current issue of H&H (8 November 2012)

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A fundraising campaign has been set up to pay the vet fees of one of the most popular horses at The Horse Rangers Association (Hampton Court).

Retired policehorse Aries (pictured) is in intensive care at Liphook Equine Hospital in Hampshire where he’s being treated for chronic grass sickness.

Grass sickness is a debilitating disease that was first seen in horses in Angus, Scotland around 1907 and remains one of equine science’s great unsolved mysteries.

It causes damage to parts of the nervous system which control involuntary functions, producing its main sign – gut paralysis.

Despite decades of research, the cause is still unknown. Although the way it attacks the nervous system, and the fact that it is not contagious, suggests some kind of toxin is involved.

Aries, a 19-year-old grey gelding has been with the Horse Rangers since September 2004 when he retired from The Metropolitan Police Authority.

Stable manager, Theresa Barratt, said: “Aries is one of our stars – as well as giving lessons, as part of our horse management, he leads our musical ride display team”.



The members and volunteers at the charity are raising funds to pay for his hospital fees.

To donate, click here.

The Horse Rangers Association (Hampton Court) is a charity that teaches young children to ride and look after horses.

More than 400 members attend each week, including those with special needs.

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Equine grass sickness (EGS) could be linked to levels of heavy metals in the soil, research by the School of Pharmacy at the University of London has shown.

And this breakthrough could lead to new ways of treating and avoiding the condition.

The study, led by Dr Sarah Edwards, looked at metal and non-metal elements in the soil at 23 sites of EGS cases and found that these grazing areas had higher levels of soil nitrogen and significantly higher levels of iron, lead, arsenic and chromium.

Dr Edwards said: “The results show a link between toxic compounds in the soil and EGS.

“Iron uptake is linked with acid soils, while three of the EGS sites were next to motorways, which would account for the high levels of lead in the soil.”

Buttercups were also found in abundance on EGS sites.

“It’s early to suggest specific strategies, but applying lime to fields that have high levels of iron, keeping the soil pH level balanced and avoiding blankets of buttercups are all sensible precautions,” Dr Edwards said.

Vet Claire Wylie of the Animal Health Trust warned that more research is needed before specific management strategies can be suggested.

She said: “There are potential issues with the study that make it difficult to say with certainty how it might affect the wider horse population.

“It would be premature to recommend novel approaches based on these findings alone.”

But owner Nicky King, who lost her mare to EGS two years ago, welcomed the research saying: “We are never going to find a cure until we understand what causes it. Any research has to be a positive step.”

This article was first published in the current issue of Horse & Hound, 11 November ’10

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Need an equine vet?

Read more about grass sickness

The bacteria Clostridium botulinum has been linked to equine grass sickness (EGS), but exactly what triggers the severe infestations has remained unclear — until now.

Researchers at the School of Pharmacy, University of London, have recently completed a study on EGS and its results make for interesting reading.

Between March 2007 and September 2008, soil, plant, and water samples from a total of 23 EGS sites and 11 control sites were studied and metal and non-metal element levels in the soil and herbage samples were assessed.

The results showed that EGS sites had higher levels of soil nitrogen, and higher levels of iron, lead, arsenic and chromium in the herbage.

Buttercups were found in this study at every EGS site.

The significantly higher levels of these elements growing in EGS sites suggest that previously unknown triggers are involved in causing the disease.

At the beginning of October this year, the Animal Health Trust announced that it had appointed Jo Ireland MRCVS as grass sickness research co-ordinator.

Jo will be responsible for co-ordinating an EGS botulinium vaccine field trial alongside the universities of Edinburgh and Liverpool.

She will also work with the Veterinary Medicines Directive and the manufacturer of a botulinum vaccine in preparing a licence for the product and a protocol for a proposed field trial.

For the full article on diseases in the ground, see the current issue of Horse & Hound, 11 November ’10

Search for an equine vet

Find out more about grass sickness

A team at the University of London is appealing to owners of property where outbreaks of Equine Grass Sickness (EGS) have occurred to get in touch as part of ongoing research into the disease.

EGS is a disease affecting pasture-grazed animals between aged between two and seven years.

Its causes are largely unknown but it is clearly linked to diet. Signs include impaired intestinal activity, and in some cases, death.

Over the past year scientists at the Centre for Pharmacognosy and Phytotherapy have been assessing the soil conditions and vegetation at sites where EGS has occurred but they wish to increase their sample size for this year.

They would also like to hear of any new cases.

To take part in the research, tel: Dr Russhawn Aldridge on 07722 376740.

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An Riding for the Disabled Association (RDA) equestrian centre near Stirling in Scotland has temporarily shut after four horses died of acute grass sickness.

The horses came down with the mystery illness last Thursday and died within four days.

Manager of the Sauchieburn Centre at Bannochburn, Sara Smith, said: “We’ve closed our doors for a week until Monday when we’ll review the situation.

“We’re feeding the remaining 18 horses probiotics and cutting down on their grazing. At the moment they look fine but this disease can strike so quickly.

“We’ve lost 50 per cent of our driving force.”

The 15-year old centre hosts more than 150 disabled clients a week.

Ms Smith, who’s been manager at the centre for 10 years, said: “I seriously hope this is the end of it but we’ll have to do some serious fundraising to recover. I must thank our vet Tina Vernon from Crieff, who’s been magnificent.”

If anyone wants to offer help to the centre please call Sara Smith, tel:07736731743.

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Horse owners and equine vets are being asked to take part in a nationwide scheme to carry out surveillance on equine grass sickness (EGS).

The scheme is the first of its kind and is being launched by scientists at the Animal Health Trust (AHT), the Universities of Edinburgh and Liverpool and the Equine Grass Sickness Fund.

The Horse Trust is funding the surveillance scheme that will analyse trends related to the disease, such as where and when cases occur across the UK

Researchers hope to collage enough information to build an accurate picture of the true welfare impact of EGS, as well as assist in the future EGS vaccine development.

“We’re appealing to owners whose horses have suffered with the illness, or vets who have treated horses with the illness at any time throughout the year, to let us know.

“It is never too late to submit a case — your information is vital,” said Georgette Kluiters, a grass sickness research assistant at the AHT.

Equine grass sickness was first seen in horses in 1907, following an outbreak in army remount horses near Dundee, Scotland. The cause of the disease is largely unknown although the nature of the damage to the nervous system would suggest that a type of toxin is involved. The disease occurs almost exclusively in horses that have access to grass.

“April to June is predominantly the time when the number of EGS cases peak in the UK. We had notification of just five cases in the first quarter of 2009, but the number of cases in the second quarter has shown a sharp 10-fold increase, with more that 50 reports so far,” added Georgette.

If you have owned or treated a horse with EGS you can help with this research by completing a short questionnaire at www.equinegrasssickness.co.uk.

All submitted information remains confidential.

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Cases of equine grass sickness (EGS) peak between April and July, and researchers are looking for horse owners to help them investigate the potentially fatal disease.

Scientists at the University of London are looking for owners whose horses have suffered from EGS or who live in an area where there have been outbreaks in the past.

The research project — run by the university’s centre for pharmacognosy and phytotherapy — is looking at the potential causes of equine grass sickness.

Little is known about the disease, though clear links have been made to some elements of the horse’s diet — either in the food or water.

Signs include intestinal problems and can be fatal.

EGS — also known as dysautonomia — most commonly affects horses aged between two and seven.

For more information or to take part, email: equinegrass@googlemail.com or tel: 020 77535846

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World Horse Welfare and the Royal (Dick) School of Veterinary Studies have launched an e-booklet on the management of chronic grass sickness.

Written by the vet team based at the University of Edinburgh, Management of Chronic Grass Sickness Horses offers advice on the diagnosis, treatment and risk factors associated with the disease.

Professor Bruce McGorum, head of the school’s equine hospital, said: “In the past 20 years, 61 per cent of horses with chronic grass sickness admitted to the hospital have been nursed to recovery and the majority of these have even returned to work.

“Sadly, horses with the acute and sub-acute forms of the disease do not recover but the research continues.”

Grass sickness damages the part of the nervous system that controls involuntary functions, leading to paralysis of the gut.

Clinical signs include difficulty eating and swallowing, depression and weight loss.

Professor Elaine Watson, head of the school of veterinary studies, said: “Great Britain has the highest incidence of grass sickness in the world, although the exact cause of the disease is still unknown.”

Treatment of cases at the Royal Dick is partially funded by the charity the Equine Grass Sickness Fund.

World Horse Welfare chief executive, Roly Owers, said: “We are delighted to have worked so closely with the Equine Grass Sickness Fund and the pioneering and dedicated team at the vet hospital to produce this invaluable e-booklet that will be indispensible to anyone who is faced with the challenges of this appalling disease.”

The e-booklet is available free online from World Horse Welfare www.worldhorsewelfare.org, the Equine Grass Sickness Fund www.grasssickness.org.uk and the Royal (Dick) School of Veterinary Studies www.vet.ed.ac.uk.

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An ongoing research project into Equine Grass Sickness is seeking public input to help develop a cure or prevent the disease.

Grass sickness in horses attacks the nervous system and can be fatal. Although there have been several scientific studies, the causes of the disease remain speculative. The UK has the highest incidence of grass sickness in the world.

The Centre for Pharmacognosy and Phytotherapy at the University of London would like to hear from any owners of animals who have suffered the disease, or premises where there have previously been outbreaks.

“We have asked for public input before and had a good response, but we still need to increase the sample size to keep track and detect which factors contribute to the disease,” said the centre’s Sabine Heinrich.

“We would like to hear about any horses or premises with any connection at all.”

Contact: sabine.heinrich@pharmacy.ac.uk or equinegrass@googlemail.com, or tel: 020 7753 5846

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Horse owners are being asked help out with a study of the often fatal equine grass sickness.

Researchers at the University of London are investigating possible causes of the usually fatal, but non-contagious, disease.

Samples from plants and soils from pastures where there have been recent grass sickness outbreaks are being analysed by the Centre for Pharmacognosy and Phytotherapy at the School of Pharmacy (University of London).

But researchers would like to hear from owners of pastures where there have not been any known cases of the disease to act as control sites.

Now is currently peak time for this research as most cases of equine grass sickness occur between April and July.

Equine grass sickness is characterised by dysautonomia, or a malfunction of the autonomic nervous system, which leads to paralysis of the intestinal tract, and is thought to be triggered by the horses’ diet.

For further information tel: 020 7753 5884

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now