Eye Infections in Horses

When treating a horse with an eye problem, be aware that the infection may affect its vision, making it jumpier than usual. Talk gently, so you don't surprise your horse if you walk up on a blind-side.

Prognosis for Horses With Eye Infections

When treated swiftly, the prognosis for horses with mild eye infections is good. However, an untreated eye infection can lead to blindness and secondary infections.

The long-term prognosis for horses with ERU isn’t as optimistic. More than half of horses with ERU won’t be able to return to their normal levels of work and may become blind. Treatment will slow progression but is not curative.5

How to Prevent Eye Infections

Keeping your horse's environment as dust-free as possible can help stave off infection. If hay is dusty or bedding is very dry, you can dampen it or use other material or bedding. Make sure that sharp edges on water troughs, metal buildings, fences, or other obstacles are covered or inaccessible to prevent your horse from wounding its eye. Pound in or pull any old nails protruding from fences or other structures. Eye and face nets may help keep flies away from your horse's eyes.

 If you outfit your horse with a fly mask or veil, ensure it isn't irritating the eye.

Check your horse's eyes daily to catch the infection early and prevent it from worsening.

Types of Eye Infections in Horses

• Conjunctivitis: Conjunctivitis is the swelling of the conjunctiva, the mucus membrane in the eye, sometimes caused by infection, allergen irritants, or foreign objects. The conjunctiva lines the inside of the eye and extends to the cornea. Conjunctivitis will cause discharge, redness, and discomfort, and if untreated, it can lead to complications like blindness.1

ERU: Equine Recurrent Uveitis, or ERU, causes recurring bouts of inflammation in the eye and is the leading cause of blindness in horses. The blindness is often caused by equine glaucoma secondary to ERU. The development of ERU is complex and involves many factors, including injury, immune system issues, and viral infection.