What’s Wrong With My Horse’s Eye?

If you read this article and remember only one thing about horse eye issues, be sure it’s this: They’re almost always emergencies.

Eye injuries, infections, or inflammation—even those that seem innocuous—not only cause severe pain but can also progress rapidly and affect vision permanently. As such, it’s important to contact your veterinarian as soon as you realize there’s a problem. The good news is many horse eye issues heal well if treated promptly and properly.

What to Watch For

Here are some telltale signs something’s wrong with your horse’s eyes or vision:

• A change in eyelash position. Look at your horse’s face from the front and at the eyes from the sides. If a horse’s eye is painful, its lashes will point down slightly instead of being perpendicular to the eyeball’s surface.
• Cloudiness (which sometimes looks like the eyeball is blueish in color).
• Tinges of red, white, or yellow in the eyeball.
• Squinting or not opening an eye fully.
• Swelling around an eye.
• Frequent eye-rubbing.
• Excessive tearing or discharge (often a thicker consistency than tears and yellow or blood-tinged in color) from an eye.
• New growths on or immediately around an eye.
• Anything else that appears abnormal for your horse.

If you notice any of these clinical signs, contact your veterinarian.

Watch: How To Safely Examine a Horse’s Eye

Tips to Remember

Equine eyes are delicate things. Make you approach a potential eye issue properly to give your horse the best chance of a successful outcome:

• Never begin treating an eye with an ointment left over from a previous issue or from a friend without first talking to your veterinarian. This is because some prescriptions can make certain conditions worse. For example, if you use a steroid ointment intended to treat uveitis (inflammation inside the eye) in an eye with a corneal ulcer (an ulcer on the eyeball’s surface), the ulcer will likely worsen, which could affect treatment success.
• Do not remove any foreign objects (pieces of hay, sticks, etc.) embedded in your horse’s eye. In some cases, surgery to delicately remove the object is the only way to save the eye.
• Once you’ve called your vet, let the eye be unless he or she has instructed you otherwise. Your horse is probably in pain, and he might move his head suddenly and cause further trauma (to the eye or his head) if he thinks you’re trying to touch the affected area.
• Horses could have impaired vision (temporary or permanent) in the affected eye, so they might be spookier or more reactive than normal. Approach them from their “good” side, and try not to surprise them with sudden movements or noises.
• Horses don’t typically like having drops and/or ointments placed in their eyes. Many learn quickly that doing their best giraffe impression can keep their eyes out of well-meaning handlers’ reach. Ask your veterinarian to show you the best way to medicate your horse’s eye.
• In some cases, he or she might recommend using a subpalpebral lavage—flexible tubing passed through either the upper or lower eyelid and stitched into place, which allows owners to administer medication from the other end of the tube, usually braided into the horse’s mane, with medication administered via the other end of the tube. It might cost more up front, but it can help medication administration go smoothly, especially if your horse has a serious or chronic condition that requires weeks to months of treatment.
• Your veterinarian might prescribe a medication to dilate your horse’s pupil, which helps relieve pain. In these cases, your horse might benefit from a fly mask with ultraviolet (UV) protection. Ask your veterinarian if one would help your horse as he recovers.
• If don’t think your horse’s eye is healing properly or the condition is getting worse, let your veterinarian know. He or she might need to conduct a follow-up exam or prescribe a different or additional medication or treatment plan to help maximize the chances of your horse making a full recovery.

Watch: How To Medicate a Horse’s Eye

Common Horse Eye Issues

You won’t be able to tell what’s causing your horse’s eye issues without a thorough ophthalmic exam from your veterinarian. But common causes of eye injury, infection, and inflammation include:

• Trauma, including blunt force trauma (picture a horse hitting the side of his head on a trailer wall or getting kicked in the eye), penetrating injuries (from a thorn, stick, piece of hay, or anything else sharp enough to penetrate the cornea), puncture wounds (should a horse slice his eye on a stall or gate latch, piece of fencing, or other protrusion), and other ocular injuries.
• Eyelid lacerations.
• Uveitis, which can be recurrent in some horses (also known as equine recurrent uveitis or moon blindness).
• Corneal ulcers.
• Conjunctivitis (inflammation of the conjunctiva, the mucous membrane lining the eyelids and covering the white surface, or sclera, of the eyeball).
• Stromal abscesses (abscesses in the stroma—part of the cornea).
• Tumors and cancers of the eye and surrounding structures.
• Glaucoma (diseases caused by increased pressure within the eyeball, which damages the optic nerve and can result in blindness).
• Fractures of the orbit (the bony structure in which the eyeball sits).

Take-Home Message

Eye issues that can affect a horse’s vision and comfort range from corneal disease to uveitis to cataracts. The most important thing is detecting these conditions early, so be vigilant for signs like squinting, excessive tearing or discharge, redness, swelling, cloudiness, or a loss of vision. If you notice any eye abnormalities, call your veterinarian right away.

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