Corneal Ulcers in Pets

We often see patients for red and irritated eyes. Sometimes the culprit is allergies, while other times it is a case of conjunctivitis. A very common condition that must be ruled out when a patient comes in with a red eye is a corneal ulcer.

The cornea is the outermost layer of the eye and the first line of defense for protecting the eye from trauma and infection. When the cornea is damaged it exposes the eye to bacteria and causes a lot of pain. Corneal ulcers can vary in severity from a superficial scratch on the eye to a deep wound that penetrates into the inner chambers of the eye.

The list of possible causes for a corneal ulcer is a long one, and a good history from the owner helps narrow down the list. The most common causes include:

  • Trauma
  • Foreign body in the eye (plant material, dirt, etc.)
  • Cat scratches
  • Chemical irritation (shampoos, grooming products, etc.)

Signs of a corneal ulcer will be a red and painful eye. The patient will squint or hold the eye shut. It may paw at the eye or rub it on carpet or furniture in an attempt to relieve the pain. You may notice a greenish discharge from the eye.

Your dog/cat should be seen as soon as possible to evaluate the eye and determine if a corneal ulcer is present. To diagnose a corneal ulcer your veterinarian will stain the eye with fluorescein. This neon green dye will highlight any defects of the cornea.

Treatment of a corneal ulcer involves using topical antibiotic ointments or drops to prevent a bacterial infection in the eye. Your veterinarian may also prescribe something for pain. Recheck visits are usually recommended about every week until the ulcer is healed.

Depending on the type of ulcer and response to treatment, the patient may need more than just eye drops. Complicated ulcers or ulcers that do not heal properly may require referral to a veterinary ophthalmologist for surgery.

If you think your pet may have a corneal ulcer, it is important to consult with your veterinarian before putting anything in the eye. Any medication with steroids (Prednisone, Prednisolone, Dexamethasone) is contraindicated if a corneal ulcer is present, as these medications can make the ulcer worse.