Two cases of equine viral arteritis (EVA) have been confirmed in stallions in Dorset.

Defra has announced that restrictions on breeding have been put in place on the two non-thoroughbreds, who are on the same yard, to limit the risk of the disease spreading. Further investigations are ongoing.

Chief veterinary officer Christine Middlemiss said: “We have taken swift action to limit the risk of the disease spreading by placing breeding restrictions on the animals and their semen.

“A full investigation is under way to determine the source and possible spread of the infection. Owners of mares and stallions are urged to have their animals tested before they are used for breeding.”

EVA is a notifiable viral disease in stallions, and in mares who have mated or been inseminated in the past 14 days. It can cause flu-like symptoms, including fever, swelling (especially of the limbs) and inflammation around the eyes. It also causes weakness in foals or abortion, especially in the second half of pregnancy.

It is usually spread by stallions with infected semen, or in the air via respiratory secretions of infected horses.

Continues below…

Understanding equine viral arteritis

All you need to know about EVA, a highly contagious venereal disease that causes abortion and severe respiratory disease

What is ‘breath energy’ and could it help your riding? Jenny Rolfe explains…

In her book 'Breathe Life Into Your Riding', an extract from which can be found below, Jenny Rolfe explains her

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

 “These findings remind us that we must all be vigilant for signs of disease and follow strict biosecurity measures,” Ms Middlemiss said.

“Owners are urged to help prevent the disease spreading, by vaccinating stallions against it and practicing good biosecurity. Owners of mares and stallions are advised to have them tested before they are used for breeding.”

Anyone who suspects the disease is present must report it immediately by calling Defra on 03000 200 301. In Wales, call 0300 303 8268, and in Scotland, contact the local field services office. Failure to do so is an offence.

For all the latest news analysis, competition reports, interviews, features and much more, don’t miss Horse & Hound magazine, on sale every Thursday.

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 industry figures are outraged at government proposals to “denotify” 2 contagious equine diseases.

Contagious equine metritis (CEM) and equine viral arteritis (EVA) — both of which are spread through breeding — are currently on the list of notifiable diseases. This means any case must be reported to Defra so co-ordinated action can be taken to stop it spreading.

EVA can cause a high rate of abortion, while CEM causes a uterine infection in mares and can lead to infertility.

But as part of the Government’s “red tape challenge” to “save businesses time and money in needless regulation”, Defra is proposing removing that status.

Roly Owers of World Horse Welfare and the Equine Sector Council for Health and Welfare told H&H this would be a “retrogade step” for managing disease.

“We understand the need to reduce the costs, but these proposals go beyond this,” he said. “Only the Government can enforce movement restrictions [bans on livestock transportation], and without them it is nigh on impossible to irradicate disease.

“This could have huge implications on the equine industry.”

The Government will be “scrapping or amending” more than 3,000 regulations, “saving businesses well over £850million every year”.

A Defra spokesman said it proposes to remove CEM and EVA from the list of UK notifiable diseases “because they are low-impact diseases which are not notifiable in the EU”.

“CEM and EVA are preventable diseases that can be controlled through good hygiene practices as well as vaccines [for EVA] and veterinary treatment [for CEM],” she added.

“Removing the notifiable status will mean government no longer having to be involved in individual disease investigations and control measures, for which effective industry led Codes of Practice are already in place.”

Richard Newton from the Animal Health Trust disagreed with this reasoning.

“The countries we deal with take the diseases very seriously and the inherent value in racing and sport horses is the knowledge that they are free from disease,” he said.

“The equestrian industry is a multi-million pound export industry and we fear Defra is being short-sighted. It needs to realise the potential trade impact if notifable status is taken away.”

Defra told H&H “no final decision will be taken on these proposals without stakeholder consultation”. Mr Owers said the sector had written to Defra.

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

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 case of Equine Viral Arteritis (EVA) has been confirmed in a stallion in West Sussex.

Few details are known about the circumstances surrounding the positive test, which came to light on Wednesday (8 December).

But Defra said in a statement: “Breeding restrictions have been put in place on the infected stallion and investigations have begun to establish the likely origin of the infection, as well as any mares that may have been affected.

“The disease is being controlled in line with the industry agreed Horse Betting Levy Board (HBLB).”

EVA is a highly contagious, viral disease that can cause a high rate of abortion in pregnant mares and can be spread by either a stallion with infected semen or in the air via the respiratory secretions of a recently infected horse.

Signs of the disease include fever, conjunctivitis and swelling of the lower legs. There is currently no treatment available for the disease.

Find out more about Equine Viral Arteritis

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 stallion that last month tested positive for Equine Viral Arteritis (EVA) in Staffordshire was imported last year, but has not been used for breeding since it arrived in the UK.

The results of a Defra enquiry found that the stallion was imported in a batch of four horses in March 2009.

“The importer is a warmblood breeder, selling showjumping and dressage horses,” said a Defra spokesman.

“The horse remains under official restrictions while its owner, vets and breeder consider the options available to them.”

EVA is a highly contagious viral infection that causes a high rate of abortion among pregnant mares.

The disease causes damage to a horse’s arteries and is transmitted through the respiratory tract — via coughing and snorting — or via semen from an infected stallion.

EVA has a wide range of signs — including fever, conjunctivitis and swelling of the lower legs — and although there is a vaccine available for it, the disease itself is not treatable.

“If a stallion with EVA has passed its acute stage of infection — when it will transmit the disease via its respiratory system — it will only infect other horses via its semen,” said British Equine Veterinary Association (BEVA) president and AI expert Dr Madeleine Campbell.

If not acutely infected, the stallion can be euthanased or castrated in isolation, or re-exported if cleared by the importing country.

Dr Campbell added: “This case illustrates that import requirements alone are not sufficient to ensure freedom from EVA and demonstrates why it is crucial that all stallions are tested free of EVA before they begin breeding duties [each time] and when they are imported into the UK.”

This article was first published in Horse & Hound (2 September, ’10)

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

Restrictions have been put in place on a stallion in Staffordshire that has tested positive for the notifiable disease Equine Viral Arteritis — or EVA.

Little has been released about the circumstances, but Defra said in a statement: “An investigation is underway to establish the likely origin of the infection, as well as any mares that may have been affected.”

EVA is a highly contagious viral infection that causes a high rate of abortion among pregnant mares.

The disease causes damage to a horse’s arteries and is transmitted through the respiratory tract — coughing and snorting — or venereally via semen from an infected stallion.

Equine Viral Arteritis has a wide range of signs — including fever, conjunctivitis, swelling of the lower legs — but is most dangerous to in-foal mares. There is no treatment yet available for the disease.

Breeding restrictions have been placed on the stallion in Staffordshire.

How to prevent the spread of disease

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 stud in Co Mayo Ireland is under quarantine restrictions after a stallion tested positive for the venereal disease equine viral arteritis (EVA).

The stallion was imported to Ireland in October 2009 but subsequently found to have no history of vaccination for EVA.

In March the stallion tested positive for EVA. Eight mares have also tested positive for the virus after contact with the horse.

The Irish Department of Agriculture is investigating the case.

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

Detailed instructions on how to further prevent the spread of Equine Viral Arteritis (EVA) are being sent to horse owners, riders, breeders, vets, farriers and competition organisers in Normandy, France.

EVA is a highly contagious disease mainly spread through mares mating with infected stallions. Flu-like symptoms are common, but EVA can also cause mares to abort. It is notifiable in the UK.

There are currently 16 outbreaks of EVA throughout Normandy, and one case in Landes. A committee of leading French equestrian organisations has been set up to monitor the spread of the disease weekly.

On top of movement restrictions in place in parts of Normandy, any horses competing in Brittany, Pays de la Loire, Ile de France, Picardy and Centre have to be certified as in good health by a vet at least a week before competition.

This news story was first published in Horse & Hound (9 August, ’07)

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

An outbreak of Equine Viral Arteritis (EVA) has been confirmed in northern France. The highly contagious disease is mainly spread through mares mating with infected stallions. Flu-like symptoms are common, but EVA is also known for causing pregnant mares to abort.

The French outbreak occurred in the Eure and Orne regions of Normandy last week. Movement restrictions have been put in place and horses in the affected area quarantined. In the UK, EVA is a notifiable disease. It is thought that four mares have been infected, but details remain sketchy.

Fritz Sluyter, head of the veterinary department at the International Equestrian Federation, said there was no need for alarm.

“A few premises have been involved after a stallion got sick and then, I believe, died. This is unusual for EVA but not a reason to panic,” he said. “We do get EVA occasionally in Europe and it is just a case of monitoring the situation.”

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