Eye Emergencies in Horses

By Matt Witzel, DVM

Never underestimate the importance of a horse’s eye. As a prey animal, horses rely heavily upon their senses to know when they are safe or in danger. Yes, horses can live reasonably well without eyesight as I am sure many of you know, but I think its safe to say they would all prefer to keep their vision if they had the choice. What’s more, the equine eye is a very fragile organ and is highly susceptible to ulceration, infection, and uveitis, all of which can lead to blindness or loss of the eye. For this reason, if there is ever any concern about the vision or health of a horse’s eye, we must asses and treat the problem before it is too late.

The most common emergency that we find involving horse’s eyes are corneal ulcerations, or scratches to the surface of the eye. These are diagnosed with the application of a fluorescent stain and can be extremely painful for your horse. Treatment involves the application of topical and sometimes systemic medications. Steroids such as dexamethasone or hydrocortisone should never be applied to an ulcerated eye as they may cause “melting” of the cornea and sometimes the loss of the eye.

Another very common problem we see is conjunctivitis, or inflammation of the conjunctiva around the eye and eyelid. This is most often caused by dust, debris, or allergies. Treatment for this condition requires flushing the eye out and the application of a steroid ointment. You may now understand how eye emergencies and treatment can be tricky when l you learn that a corneal ulcer and conjunctivitis can present with almost identical symptoms but require opposite treatments. Missing the correct diagnosis or mixing the treatments can have severely detrimental effects to your horse’s vision.

Uveitis, or inflammation of the interior of the eye, is another common problem we find in horses. This, unlike the previous two ophthalmic conditions, can be associated with certain breeds such as Appaloosas, POA’s, and Paint horses. This can present as a single occurrence or chronically as Equine Recurrent Uveitis (ERU). Uveitis can be painful and requires immediate topical and system treatment. If ERU is left unchecked, it will very often cause blindness in one or both eyes. Luckily, these uveitis episodes in ERU patients can be dramatically reduced with proper management and medical strategies.

There are many other conditions that can affect the eyes of our horses and as a general rule, eye problems are best treated as emergencies. If at any point you find your horse squinting, holding an eye shut, producing excessive discharge, or see discoloration of an eye please call your equine veterinarian immediately. And only after an ophthalmic exam is performed will you know how to properly treat and minimize further damage to your horse’s eyes.