What you see. The starting point for addressing any equine health related issue is your observation.


Eye looks Blood Shot, White of Eye is Red


In a healthy horse, the white of the eye (sclera) should have only a few small blood vessels visible on the surface. The sclera is a good indicator of the circulatory health of the horse, and also of the health of the eye. To see the sclera, use your index finger to push the upper eyelid upward.

A bloodshot eye is an important finding that can mean a variety of things. It can result from traumatic injury, infection, inflammation, a foreign body, or be an indication of a body-wide (systemic) disease. An example of this is a bloodshot appearance to the white of the eye in horses with endotoxemia (endotoxin in the blood).

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your role


What To Do

Assess your horse's eye. Always compare the appearance to that of the other eye. Look for other signs of eye injury, particularly watering and grayness to the clear corneal surface. If you notice other eye signs, the problem is probably related to the eye itself.

Assess your horse's general health using the Whole Horse Exam (WHE), paying particular attention to the opposite eye, attitude, appetite, rectal temperature, heart rate and gum color. Contact your vet to discuss your findings and concerns.

your vet's role

Your vet will perform a physical exam and other diagnostics to determine whether this is a local problem or whether it relates to body-wide health. In cases where the eye is reflecting body-wide health, we would expect to see similar changes in each eye.
Questions Your Vet Might Ask:
  • Do you notice the problem in one eye or both?
  • Do you notice the horse squinting or holding the eye closed?
  • Do you notice the eye watering or any discharge?
  • Does the horse's appetite and attitude seem normal?
  • Do you notice an injury near the eye?
  • What are the results of the Whole Horse Exam (WHE)?

Diagnoses Your Vet May Consider

The cause of the problem. These are conditions or ailments that are the cause of the observations you make.

Very Common
Less Common
more diagnoses

Author: Doug Thal DVM Dipl. ABVP