Horses have the largest eyes among land animals. This makes it easier in spotting predators and this is very helpful as they are mainly animals of flight. But large eyes makes the more susceptible to injuries and infections. A number of common equine infections may affect them in the eyelid, retina or the whole eye.
Below are listed the eye diseases that affect horses commonly.
Diseases
Eyelid
- Entroption: Eyelashes brush against the eyeball.
- Eyelid melanoma and sarcoids: Small tumors appearing either alone or in groups and may be benign or cancerous.
- Squamus cell carcinoma: Most common infection (Horse Owner’s Home Veterinary Handbook) which is most often cancerous and seen in older horses with white eyelids.
Eye
- Three kinds of glaucoma, viz., congenital, primary and secondary (resulting from a previous infection)
- Three kinds of recurrent equine uveitis (also known as “moon blindness”), viz., classic, posterior and insidious
- Congenital stationary night blindness, which is genetic and affects the retina
- Anterior segment dysgenesis, which is also genetic and hinders normal growth of the froontal portion of the eye
These are some symptoms to identify whether a horse is suffering from any of the above mentioned diseases.
Symptoms
- Squinting in the dark
- Excessive eye discharge
- Mucus on eyeball
- Inability to close inner eyelid
- Cloudy or bluish pupils
- Blank look in the eyes
Causes
There are a number of causes for equine eye infections. They may be genetically prone to infections. But the most common cause is a previous injury that then leads to infections of the retina, inner eyelid or the entire eye. Earlier infections caused by bacteria r fungi may also make them prone to frequent infections later on. But primary glaucoma is a disease whose cause is yet unknown as it may develop in horses with no history of injuries or infections.
Breeds
There are some breeds that are more prone to infections and diseases that other breeds due to their genetic disposition. American saddlebreds, Appaloosas, Arabians, Belgians, Percherons, Tennessee walking horses, miniature horses, thoroughbreds, Morgans, Morabs, Quarabs, quarter horses, quarter ponies, Rocky Mountain horses, Pony of the Americas (POA), Paso Finos, standardbreds, warmblood or sporthorse breeds, such as the Trakehner, and mules with atleast one parent of the mentioned breeds are some such breeds of horses.
