Horse Equine Recurrent Uveitis: Welfare and Treatment

Equine recurrent uveitis is the leading cause of blindness in horses worldwide, causing recurring painful eye inflammation with progressive vision loss that substantially affects welfare.

Key Facts

ERU affects up to 25% of horses in some populations, with Appaloosas overrepresented with up to 8x increased risk
Recurrent inflammation episodes cause progressive damage to intraocular structures leading to blindness
Leptospira infection is a recognized cause of ERU in many geographic regions
Signs include photophobia, tearing, a closed eye, cloudiness, and miosis (pupil constriction)
Intravitreal cyclosporine implants significantly reduce recurrence rates and preserve vision in many horses
Enucleation (eye removal) may be necessary in chronically painful, non-visual eyes

Welfare Considerations

ERU causes recurrent acute eye pain that is distressing for affected horses and challenging for owners to manage. Between acute episodes, low-grade inflammation may cause ongoing discomfort that is easily missed. Progressive vision loss affects a horse's safety, confidence, and ability to be ridden. Horses going blind from ERU require significant management adaptation. The availability of cyclosporine implants has transformed the prognosis for many horses, but access to this specialist treatment is not universal. Early diagnosis and appropriate specialist referral improves welfare outcomes significantly.

What You Can Do

Seek immediate veterinary assessment if your horse shows a closed, painful, or teary eye
Ask about referral for cyclosporine implant surgery if your horse has confirmed ERU with frequent recurrences
Administer topical anti-inflammatory medications promptly at the first sign of an acute episode
Adapt management for horses with vision impairment including consistent routines and predictable environments
Test horses for Leptospira antibodies to identify a treatable underlying cause of ERU