Common eye problems in horses

Did you know that horses have the biggest eyes of any land mammals? Their extraordinary eyesight helps them spot predators long distances away, so is essential to their survival. Eye issues are also a big deal to domesticated horses as they can have a significant impact on welfare and performance. As soon as you spy anything awry with your horse’s eye, seek veterinary advice as soon as possible.

Common eye issues in horses

Corneal ulcers

Eyes can become ulcerated when the surface has been damaged. They are very common and are often caused by scratching or a horse getting too close to undergrowth – the downside of such large and prominently positioned eyes. Very shallow ulcers sometimes heal quickly on their own with no scarring. However, deeper ulcers can fast become an emergency and result in the eye rupturing. Ulcers can be extremely painful and might cause a horse to try clamping shut the streaming, affected eye.

Equine Recurrent Uveitis (ERU)

ERU is an extremely serious auto-immune condition. It causes swelling inside the eye and is thought to eventually cause blindness in half of affected horses. Typically, horses will appear to be squinting and there might be discharge visible. The condition is very painful. It is thought that there might also be a hereditary element to ERU as some breeds, such as Appaloosas and Warmbloods, appear more affected than others.

Eye trauma

Lacerations to the eyelids or area very close to the eye can occur when a horse rubs its head on something or knocks itself when being alarmed by a sudden noise, for example. Significant injury to the eyelid can have serious consequences if it reduces the lid’s ability to protect the eye. Eyelid lacerations sometimes require sedation, so a vet can closely examine the eyelid and also check for ulcers on the surface of the eye. Sarcoids, which initially may appear a small, raised lump, sometimes grow so large that they obscure vision, and given their location can be harder to treat than sarcoids in other regions.

Immune-Mediated Keratitis (IMMK)

IMMK is not usually painful and the signs of it can be extremely subtle. Sometimes the only indication of this condition, where the horse’s own immune system attacks the eye’s surface, is a slightly cloudy white patch on the eye. Immunosuppressive eye drops or ointment are usually the first course of action.

Bacterial Conjunctivitis

This presents are a swollen, inflamed and red inner eye lid and is often caused by flies or the horse rubbing dirt into the eye. It is treated with antibiotic ointment.

Flies can cause a host of eye problems in horses

Fly masks can be a good idea to help protect eyes and help keep flies away but they should be appropriately fitted and the sort where one can see the eye through the mesh. Masks should also be removed regularly and checked at least twice a day.

If you have any concerns about your horse’s eye, consult a vet immediately.