Your pet’s eyes are vital to her well-being. In my previous blog focused on pet eye health, I went over conjunctivitis, which is the most common ocular condition I see. I think the second most common problem I see in the exam room is corneal ulcers.

Scratching the surface

The cornea is the clear outer surface of the eyeball. Despite being protected by tears, upper and lower eyelids, and the third eyelid that our dogs and cats have (yes, really!), the cornea is still prone to scratches and trauma. The cornea can be injured by many things, including:

  • Rough contact with plants, thorns, and bushes
  • Scratches from other animals (especially during fights)
  • Self trauma - If your pet‚Äôs eyes are itchy or irritated from other reasons, such as conjunctivitis, he may paw at them and inadvertently scratch the cornea.
  • Chemical irritation from things such as shampoos
  • Foreign body injury, including anything from dirt and thorns to irritating eyelashes

Signs and symptoms

Symptoms of a corneal ulcer tend to have a sudden onset. Redness, pain, a blueish tint to the eye (caused by swelling in the cornea) and squinting are common signs of an injury to the cornea. If your pet shows up with a red, painful eye, it’s best to get to the vet as soon as possible. Corneal ulcers are very painful, and if left untreated, they can worsen significantly and may lead to rupture of the eye.


Your veterinarian should be able to easily diagnose a corneal ulcer. To do so, a complete eye exam will be performed. Sometimes, a corneal abrasion is apparent on a routine eye exam. But often, your veterinarian will need to perform a special test.

A special stain, called fluorescein, will be applied to the affected eye. This stain will cling to the ulcer and cause the spot to glow bright yellowish-green under a black light. This will help your veterinarian see the distinct borders of the abnormal area, which will help determine how well it is healing at your pet’s follow-up appointment.

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Most of the time, minor scratches and ulcers heal without complications. Your pet will go home with some medications, including eye drops or ointments that prevent infection and help with healing and pain. The eye drop for pain may cause the pupil of the eye to dilate, making that eye more sensitive to light.

Sometimes clients fear that the eye is not getting better because their pet is still squinting, but this may simply be due to light sensitivity.

Don’t forget to follow-up!

Your veterinarian will want to see your pet back for a recheck to make sure the ulcer is healing properly. It is important to keep this appointment, even if you think the ulcer is resolved. It is equally important to call your veterinarian if you think the eye is not improving before the recheck.

Occasionally, deep ulcers can be quite stubborn and the healing process more difficult. In these cases, extended treatment and rechecks (and possibly surgery) will be needed, and having pet insurance can be a real benefit when the vet bills start rolling in!

Oct 26, 2011
Pet Health

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