While there are many reasons for a horse to have excessive tear production, it’s a classic sign of equine recurrent uveitis, also known as moon blindness.

A new website launched by the Montana-based Rolling Dog Ranch Animal Sanctuary examines research on uveitis and blindness in Appaloosa horses.

“Moon blindness” is a chronic, painful eye disease, and it’s the most common cause of blindness in horses. It was so named during the 1600s because people thought recurring attacks were related to phases of the moon. This eye disease might be one o

The horse, Lexius (Lexi), a 13-year-old Dutch Warmblood mare, had an infection in the vitreous that caused chronic inflammation and uveitis in both eyes. The most likely cause of the infection is the bacteria leptospirosis.

The lessons I learned from this experience are that if an eye infection does not resolve–or look much improved–in a week, then seek an ophthalmologist or at least ask your veterinarian to take samples of the infected area for further study.

Is there any food, treat, or climate that causes moon blindness flare-ups?