Eye Diseases

Eye diseases can be a major problem for any horse owner. They are also the most dangerous horse diseases for humans. A horse with bad eyes can get spooked easily and lash out at people they know. Horses with eye diseases are also dangerous to ride.

Knowing about the diseases that affect horse eyes and how to spot them is a great way to protect your horse and yourself.

All About Horse Eye Diseases

Well-maintained eyes are a big part of maintaining horse health. There are many eye diseases that affect them. Some are hereditary or congenital. Others are brought on by sickness, environment and other factors. Some of the congenital diseases include the eyelid dividing into two, the eye not developing fully or the eyelids being stuck shut. The last two are a little more serious and sometimes can”t be fixed.

Other horse eye diseases have to do with the nerves. Spasms of the eyelids are just one of these. Drooping eyelids (also called ptosis) are another problem linked to the nervous system. It”s usually seen in the upper lid and is usually a side effect of paralysis in the face. It can also sometimes be caused by a spasm of the sphincter muscle, which closes the lid or an inflammation of their upper lid.

Inflammation of horse eyes is caused several different things. One cause can be a defect in the horse”s eye. Another cause can be an eye injury caused by objects or chemicals the horse came across. Once it”s diagnosed, you can tell what caused it by checking for any wounds near the eye and checking their food supply and environment for anything that might have bothered them. If there is nothing to suggest these are the causes, it”s most likely a genetic defect. Knowing what caused the problem will help to treat it.

Another problem that affects horse eyes is sty. Sty is also known as a boil in the eyelid and is also classified as an inflammation. The inflammation ends up forming into a firm, round object near the margin of the horse”s lid. It will usually burst in about four or five days. There are different ways of making it heal more quickly, which your vet can tell you about.

Entropion, also called inversion/eversion of the eyelid, is another disease your horse can come down with. Usually, this happens when a horse”s eyes have been wounded. Entropion can also be caused by ulcers, tumors, skin diseases and other factors. This can be one of the more serious eye diseases, because it usually means surgery.

Growths are also common eye diseases. The eyelids are a favorite spot for tumors and warts to form, so the eyelids need to be checked for any unusual growths pretty often. This is especially important when there are tumors, because they can end up spreading elsewhere. Removing these growths is usually pretty quick and is sometimes followed by applying different medications to the area. Other diseases include torn eyelids, conjunctivitis (an inflammation of the outer part of the eye), cloudiness of the cornea and moon-blindness.

Signs of Eye Diseases

Finding problems early can help save your horse”s vision and make treatment easier. If horse eyes are cloudy, have no transparency or are opaque, there is likely a problem. Redness of the eyes, swelling and stiff lids are also a sign of different eye diseases. It”s a good idea to check a horse”s eyelashes to make sure they”re all facing outward. Sometimes, the lash is turned toward the eye and is causing irritation.

Tears are another sign of eye diseases. If they run down the side of the cheek, there could be a problem because tears normally move toward the nose. Also look out for dilated pupils, any changes in your horse”s step and reaction to things. A horse with eye problems will take higher steps to try and avoid stumbling over things. It”s usually best to have a vet look over the horse to figure out exactly where the problem liew.


Law, J., F.R.C.V.S; et al (2007). Diseases of the Eye. Retrieved March 8, 2008, from from the Project Gutenberg Web site: http://www.gutenberg.org/files/23403/23403-h/23403-h.htm#Page_274.