By Dr. Sarah Witt, BVM&S
Finding your horse with a suddenly swollen or changed eye can be a scary sight. Acute eye disease is one of the most common emergencies we get calls about. Horses are often found with one eye so swollen they can’t open it, or it’s dripping with goopy fluid. Other times you might notice a change to the surface of the eye, such as a blue or cloudy appearance, or an obvious defect on the surface. All of these symptoms should be taken seriously, eyes truly are emergencies.
The most common eye emergency is corneal ulcers. The cornea is the clear surface of the eye, and it is susceptible to trauma or being scratched. The resulting ulcers are extremely painful, no matter the size. They can be imperceptible to the naked eye or obvious from several feet away. Horses usually present with a swollen eye, squinting, and tearing or purulent discharge. Treatment of simple corneal ulcers involves topical antibiotics, atropine to dilate the pupil, and systemic anti-inflammatories. More severe corneal ulcers may require intense medical treatment every few hours around the clock or even surgery to remove the damaged cornea and place a graft over top. The sooner treatment is started, the better the prognosis.
We also receive calls about lacerations to the eyelids which require surgical reconstruction. Suturing eyelids back together is a delicate job. If the laceration involves the eyelid margin (where the lid touches the eye surface), these must be reconstructed as accurately as possible to prevent an abnormal lid rubbing on the eye and causing a corneal ulcer.
Other times we see horses with suddenly blue or cloudy appearing eyes. Often this is an indicator of uveitis. Uveitis is a fancy word meaning inflammation of the eye. Again, this is a very painful condition even if you don’t see obvious signs of pain in your horse. The longer the inflammation is present, and more severe it becomes, we see more damage to the eye itself. Uveitis can come back in future flares, termed Equine Recurrent Uveitis which is commonly seen in Appaloosas as well as other breeds. In these cases, if not controlled with medication, the uveitis results in severe damage to the eye and ultimately causes blindness.
There are many other diseases of the eye that we diagnose and treat, this is just a taste of some common ones. My main takeaways for horse owners is that any eye disease is painful and should be seen for veterinary care as soon as possible. What initially appears to be mild disease can quickly progress to severe disease, making treatment more difficult and often more expensive. I will also warn you against putting any medication in your horse’s eye without veterinary guidance, as many medications can worsen certain eye conditions when used improperly.
When eye disease in horses is found and treated early, we have the best response to therapy. Finding your horse with a sore eye is alarming. Reach out to your vet as soon as you are able and keep the horse calm while you wait.