Eye Infections and Injuries in Horses

Eye injuries and infections are common in horses due to the size and protuberance of their eyes. This is just one of the reasons why you s...

Eye injuries and infections are common in horses due to the size and protuberance of their eyes. This is just one of the reasons why you should examine your horses - and not just from the other side of the fence - at least twice a day.

With timely treatment, many eye problems can be brought under control within a few days. In most cases, a veterinarian should examine the eye, but most measures can be performed by you at home.
What are eye infections in horses?

The most common eye problems in horses include bacterial infections and traumatic wounds.

Untreated eye problems can become malignant very quickly. Smaller problems can even lead to blindness if left untreated. If the eye becomes severely infected, the structures of the eye can be eroded until the entire eye collapses. Eye problems are also extremely painful and should be treated as soon as possible for animal welfare reasons.
Symptoms of eye infections in horses

The eyes of your horse should be clear, bright and the eyelids tight, with the inside of the eyelid being pale pink and moist. The flow of tears should be minimal and perhaps only have a drop in the corner of the eye. Sometimes, when a dusty, dry wind blows, a horse's eyes can run a bit, just like yours.

Symptoms that require treatment include:

•     Cut or ripped eyelids
•     Swollen eyelids1
•     Obvious damage to the eye itself
•     White film either all over the eye or in spots
•     Red or inflamed eye or surrounding tissue, including white sclera and eyelid1
•     Tears on the horse's face that may indicate a blocked tear canal
•     Extensive discharge except a thin tear-like stream
•     Tumors that grow on or around the lid
•     Turned under the eyelids in foals, which causes the eyelashes to rub on the eye

 Causes of eye infections

Horses can develop an eye infection after a foreign body has been stored. When the surface of the eye has been scratched, bacteria from the environment can quickly cause infection. This makes the eye of the horse appear cloudy and red. The horse is probably snarling and threshering and may be reluctant to let you look closely. These types of infections should be seen by a veterinarian who prescribes antibiotic ointment and perhaps other therapies to help treat the infection and cure the eye.

Recurring uveitis is another, much more serious eye infection in horses that, if left untreated, can lead to blindness.2 This disease, also known as moon blindness, can have several causes. Research has shown that a bacterial disease called leptospirosis may be the cause, although it is thought that there are other causes as well.

Signs of uveitis include squinting and hypersensitivity to light, a cloudy eye and eye pain. The symptoms can flare up and then decrease again, only to flare up again.

Infection with the parasite Thelazia, also known as eyeworm, is also a cause of eye diseases in horses.3 Horses are infected with this parasite via flies. Thin worms can be made visible inside the eye. A veterinarian must remove the worms from the horse's eye using surgical instruments (usually with pliers) while the animal is under sedatives. Fortunately, these parasitic infections are rare in horses in the United States.

Treatment

If your horse has an eye injury or infection, call your veterinarian as soon as possible. Rapid treatment is the key to a successful outcome for any eye problem. While you're waiting for your veterinarian, here are some things you can do to help your horse:1

• Eye and facial nets can help keep flies away; Fly masks or veils should be avoided as they can rub or hit the eye.

•     If possible, keep your horse in muted light, e.g. in the stable, until the veterinarian arrives.

Your veterinarian will probably sedate your horse for a thorough eye examination. Do not try to open the eye of a horse by force, because a horse can be extremely head-shy when the eye is aching. Cracks and tears in the horse's eyelids should be treated by a veterinarian so that the eyelid can be sewn if necessary. The veterinarian also checks for damage to the cornea and for anything that can get stuck in the eye (sliver, blade of grass or split). The veterinarian can assess the general state of health of the eye and possibly detect problems that are not recognizable to the untrained eye.

If an infection is diagnosed, your veterinarian is likely to give you an ointment or gel that is applied to the eye several times a day.4 In some cases, he can remove a vial of the horse's blood and make a solution to rinse the eye; the serum in the horse's own blood acts as a remedy for the eye tissue. For all medications, make sure that you follow the instructions of the veterinarian carefully and are embarrassingly clean when applying dressings or ointments.

Care at home

Just because you see a significant improvement within a few days, you should not discontinue the drug until the entire course is complete. Discontinuation of treatment before the infection or injury is fully healed can cause the infection to re-ignite and possibly cause further damage.

If you are working with a horse with an eye problem, you should be aware that it may have a veiled view and is a bit more erratic than usual. Speak softly so that you don't surprise your horse when you climb on a "blind side".

How to prevent eye infections and injuries

The environment of your horse should be as dust-free as possible. If the hay is dusty or the litter is very dry and dusty, moisturize it or use other food or litter. Make sure that sharp edges on water troughs, metal buildings, fences, or other obstacles are covered or inaccessible.4 Smash or pull out old nails that could protrude from fences or other structures.

By making your horse's home as safe as possible, you can avoid unintentional eye injuries.