Equine Recurrent Uveitis: Welfare and Surgical Management

Equine recurrent uveitis (ERU) is the most common cause of blindness in horses, causing repeated painful inflammatory episodes that progressively destroy vision without intervention.

Key Facts

ERU affects approximately 8-25% of horses in some populations, with Appaloosas and Warmbloods predisposed
Repeated episodes of uveal inflammation cause progressive ocular damage and eventual blindness
Clinical signs include photophobia, lacrimation, corneal oedema, and miosis during acute episodes
Cyclosporin A intravitreal implant provides sustained immunosuppression and significantly reduces recurrence
Without treatment, most affected eyes become blind within 5 years of disease onset

Welfare Considerations

Equine recurrent uveitis causes acute intense ocular pain during inflammatory episodes, with horses showing photophobia, blepharospasm, and evident distress. Repeated episodes cause cumulative intraocular damage — synechia formation, cataract, and retinal degeneration — leading to progressive vision loss. Blindness in one or both eyes significantly compromises horse welfare through increased anxiety and reduced ability to interact normally with the environment. Intravitreal cyclosporin A implants represent a significant welfare advance by reducing episode frequency and severity, protecting residual vision, and reducing cumulative suffering from repeated acute uveitis.

What You Can Do

Seek prompt veterinary assessment for any horse showing signs of acute ocular inflammation
Implement topical anti-inflammatory treatment during acute episodes to reduce pain and inflammation
Discuss intravitreal cyclosporin A implant with an equine ophthalmologist for horses with frequent recurrence
Manage blind horses with consistent stable environments that minimise hazards
Monitor the fellow eye carefully in unilateral ERU cases as bilateral disease is common