Equine Eye Diseases

Equine eye diseases

Horses’ large, prominent eyes are positioned so that they can see almost 360ᵒ around themselves. This is great at helping them spot predators, but it can have its flaws. Their eyes are fragile and prone to injuries and diseases which can, if left unattended, have a devastating impact on their vision.

Signs of eye pain

  • A watery eye
  • A fully/partially closed eye
  • Discharge
  • Redness, inflammation or swelling of the eye
  • Sensitivity to light
  • Excessive blinking or squinting
  • A change to the colour of the cornea
  • Rubbing the eye against the inside of the knee or other objects

Common equine eye problems

  • Conjunctivitis
  • Corneal ulcer
  • Uveitis
  • Foreign body
  • Eyelid wounds


This is the inflammation of the conjunctiva (the soft pink tissue inside the eyelid). It can be sore looking and swollen accompanied by a watery or pus-like discharge. Causes include:

  • Trauma
  • Allergens, such as pollen
  • Irritants such as wind, dust, flies, and chemicals
  • Virus
  • Bacterial infections
  • Parasites

Most cases of conjunctivitis resolve within a few days of treatment with an antibiotic ointment, sometimes with the addition of a steroid.

Corneal ulcer

Corneal ulcers can appear and progress very rapidly and are usually very painful. Often it is accompanied by a condition called Uveitis which is inflammation within the eye itself which makes the horse very sore. Initial presentation is a closed, swollen eye, often running with tears. Our vets will diagnose corneal ulceration by putting a fluorescent dye into the horse’s eye. Affected areas will take up the dye and appear green.

Treatment of ulcers of the eye is directed at identifying and rectifying any underlying cause of the ulceration, controlling infection and inflammation with the use of antibiotics, anti-inflammatories, and pain relief.


Uveitis is the inflammation of the inside of the eye. There are many possible causes including trauma, infection and are is often associated with a corneal ulcer.

It is important for your horse with this condition to stay out of bright sunlight and this can be achieved by wearing a fly mask which will filter out various amounts of UV light.

Uveitis is treated with antibiotics, anti-inflammatories and pain relief but can take a couple of months to resolve. Uveitis can be re-occurring.

Foreign body

Even though a horse has a brisk blink response, occasionally a foreign body will go into the eye. This might be a grass seed sat in the conjunctival sac or a thorn or twig that has penetrated the cornea. The latter is extremely serious, and the horse will most probably have to be referred to an equine hospital to have it removed.

Eyelid wounds

It is very important that they are stitched up and allowed to heal correctly as an upper eyelid defect as a result of a poorly healed wound can result in horrible consequences for the actual eye itself due to a dry eye.

Tips in the event of an eye injury

  • If the horse’s eyelids are shut, never try to force them open. This may further damage the eye.
  • Horses with eye injuries are often sensitive to light. By placing them in a darkened, clean stable we can instantly make them more comfortable. Alternatively applying a fly mask will help to increase their level of comfort.
  • If an “object” appears to be protruding from the eye do not try to remove it. This may be a foreign body and attempted removal may further damage the eye. However, it may be part of the inside of the eye itself that is “helping” to plug the wound.
  • Do not be tempted to use any old or previously used eye medication.
  • Do not wipe away any discharge coming from the eye prior to any veterinary examination. Once the vet has examined the eye any further discharge should be removed. The application of petroleum jelly may reduce scalding of the adjacent skin.
  • Fly control is important in any case of eye injury to prevent further irritation and discomfort being experienced by your horse. This may take the form of a fly mask, fly repellent sprays or barrier creams.
  • Feeding from the floor may aid in reducing dust in the environment which may irritate the eye. Soaking hay is advisable where possible.

Horses are often inclined to rub at a painful eye. Until veterinary attention is sought ideally stay with the horse to prevent them from rubbing.

In all cases any injury or disease affecting your horses’ eyes is always an emergency and you should call us immediately.

If you have further concerns or queries about your horses’ eyes, then please give us a call.