perlino horse

book-fanatic  asked:

In my story, I was thinking about having a blind or semi-blind pony. I read somewhere that perlino or albino horses with pale eyes are more prone to blindness, so would that be logical? Would age be a factor in this pony's blindness?

Blue eyed horses are no more likely to develop vision problems than brown eyes horses, as found by a study our of Illinois in 2014. However, the Appaloosa breed is more prone to developing Equine Recurrent Uveitis (ERU) which is the most common cause of blindness in horses.

Perlino, American Albino and blue eyed, white faced horses are more prone to Squamous Cell Carcinoma, an aggressive cancer. This is the only eye problem that they’re more prone to.

There are lots of different ways a horse can have vision impairment. These include but are not limited to: Cataracts, severe corneal ulceration, Equine Recurrent Uveitis (ERU) and head trauma. Any of these might be useful in creating your equine character.

Cataracts can occur at any age, including from birth. While most foals with congenital cataracts are treatable with surgery there are costs involved which means not every foal will have that done.

Corneal ulceration, either due to trauma, bacterial or fungal infection can cause permanent scarring or even blindness. If the ulcer becomes severe enough to rupture the eye, the horse may even need to have its eye surgically removed.

Head Trauma is a dramatic way to give any horse blindness. The occipital lobe of the brain (which processes visual input from the eyes) is located at the back of the skull. Any trauma to this area can result in an injury to the brain and partial or complete loss of vision. Usually this happens either by a horse rearing and striking its head against a beam/branch, or my rearing and falling over backwards to slam its head against the ground. A well-placed kick from another horse could potentially do this too, but it would be an unusual spot for one horse to manage to kick another.

Equine Recurrent Uveitis can occur in any breed but is known to have a genetic predisposition in the Appaloosa. It’s not totally clear what causes this condition, whether it’s a hypersensitivity to a nutritional or infectious cause, but once a horse has it they’re not really ‘cured’ just ‘managed’. These horses typically have multiple episodes of the acute flare up (hence recurrent) and the whole eye can be inflamed. Over time this will cause damage to the retina at the back of the eye. Blindness may be partial or patchy at first, but will progress over time. Therefore a horse that has had this condition for a longer time, or with more acute flareups, will have less vision. This is the most common cause of blindness in the horse.

( ERU photo from NC State College of Veterinary Medicine)