Corneal Ulcers, Canine and Feline - contd.
Trauma is the most common cause of corneal ulcers. Typically, cats and dogs obtain scratches to the eyes from other animals or from tree branches. Also, a rough particle of dirt, gravel or other material stuck under an eyelid can damage the cornea. Other types of trauma include chemical burns from shampoo, medicated dips, and other substances. Surrounding hair that continually rubs the cornea, as occurs with entropion, or inverted eyelid, or an eyelash that continually rubs the cornea, may cause ulceration.
Keratoconjunctivitis, or "dry eye," can cause corneal ulceration. In this condition, tear production is inadequate. As a result, the eye can dry out and the surface layers of the cornea can break down.
Viral infectious diseases like feline herpesvirus or various bacterial infections can cause corneal ulcers in cats. Identification of the underlying cause of the ulcer, whenever possible, will facilitate treatment and the prevention of recurrent ulceration.
A structural problem at the cellular level may underlie superficial corneal ulcers that recur or fail to heal. In these cases the corneal epithelium is abnormal and the cornea is predisposed to spontaneous ulceration. Both eyes of an affected animal may ulcerate when defective corneal epithelium is present. These structural problems are more likely to occur in middle-aged to older breed dogs. This is especially true in the Boxer breed, which appears to have a genetic predisposition to spontaneous corneal ulceration.
