We may be relatively safe from hazardous insects, reptiles and other attackers here in the UK, but there are still creatures that can deliver a nasty nip or sting.

When H&H reader Nina Boex brought her 14-year-old gelding, Venture, in from the field last summer, she was alarmed to spot an area of raised swellings on his left shoulder.

“Venture is good-natured and doesn’t complain, but he seemed very uncomfortable,” said Nina. “The swellings spread into his armpit and almost to his knee, like a large area of fly bites, and the skin was hot to the touch.”

As the swellings grew, Nina cold-hosed the area and applied cooling aloe vera gel. Venture was prescribed further treatment by the vet, but the exact cause of the swellings remained a mystery.

“It wasn’t until the lumps started to go down that we noticed a small scab on each one, like a pinhead,” explained Nina.

“The vet said they were probably the stingers from bees and that a swarm had possibly passed through Venture’s field and stung him. For two weeks Venture stood with his head on the floor, looking very sorry for himself.

“We suspected that he had a large amount of poison in his system, so we rested him for some time. It wasn’t until autumn that he was back to his usual perky self and I could start riding him again.”

A sting in the tail
Humans can develop a life-threatening anaphylactic allergic reaction from an insect sting, but this is less likely to happen with horses. Even so, horses and bees do not mix well.

While the odd bee or wasp sting is unlikely to be an issue, an encounter with a swarm is different. Horses can panic and injure themselves as they try to escape. They may also be stung — their hair coat provides surprisingly little protection.

Always ask your vet to check a horse that suffers multiple stings, particularly on the muzzle or nostril area, because this could affect his ability to breathe.

But this is a rare occurrence. I keep bees and they are bred to be gentle. The same can be said with most commercial hives, so the stories of “killer bees” are more horror film than truth.

Most bees only swarm once a year when looking for a new home. They can be irritated by loud noises such as machinery, however, and are attracted by some scents, including citronella, which is often used as an equine fly repellent.

Know your snakes
Adders are the only poisonous snakes present in the UK, but confirmed snakebites in horses are rare. I have never encountered an equine fatality in Britain as a result of an encounter with a snake, though suspected bites can cause nasty swelling.

Horses are most commonly bitten on the nose, face or neck. They are thought to have poor close-up vision, so if they spot a snake on the ground they may be attacked when they lower their head to sniff the reptile.

In parts of the world where there are more poisonous snakes, the severe facial swelling and respiratory distress from snakebite can be very serious.

Snakebite first aid can involve inserting short lengths of tubing up the nostrils to allow the affected animal to breathe. I recall being a little surprised to see trail riders in the USA having such tubing in their first-aid kit, but I doubt it is necessary here.

A snakebite will show as two tiny wounds often surrounded by a little blood and swelling. It makes sense to know what an adder looks like as opposed to a harmless grass snake, so you know what to avoid.

Flying enemies
Smaller insect attackers are much more common pests. Most horses are irritated by flies, compared to the very few that are bitten by snakes or stung by bees.

Horses bothered by flies become irritable and are often unwilling to concentrate when working. Injuries can happen because they kick out to flick off a fly and collide with another horse or person instead. Flying pests are also potential disease carriers.

Insect bites cause an array of common problems such as sweet itch — an allergic reaction or hypersensitivity to various breeds of midge or black fly.

Sweet itch affects around 5% of the UK horse population, with more cases seen in ponies and heavy horses.

It causes a debilitating itchy skin condition due to an allergic reaction to the saliva, which is injected when these tiny insects bite. Sufferers will rub relentlessly on anything they can, damaging fences, gates and themselves in the process.

Different breeds of midge attack different areas of the body, some affecting the mane or tail areas and others targeting the undercarriage. They seem particularly bad at the moment with the warm and wet weather.

Larger flies are nearly as troublesome, because they spread infection by landing on wounds, which they are attracted to, and contaminating them. This is why vets are reluctant to geld colts when flies are plentiful.

Ticks are another danger. These blood-sucking pests, which attach themselves to the skin with barbed mouthparts and sticky secretions, can transmit infections including Lyme disease. In large numbers, they can cause skin irritations and even anaemia.

Repellents and insecticides containing permethrin or cypermethrin will provide several hours of protection. Some over-the-counter products based on natural ingredients, such as botanical oils, may give limited protection for short periods but are generally less effective.

If you live in an area where ticks are present, check your horse regularly — especially the lower legs, head and mane. Your vet can advise you of the most effective way to remove a tick without leaving the mouthparts behind.

The full article about bugs was first published in the 10 July issue of Horse & Hound magazine

Read more about fly protection