Corneal Injuries and Problems in Dogs
An ulcer is similar to a corneal abrasion, except that an ulcer is deeper
and involves the middle and sometimes the inner layer of the cornea.
Most corneal ulcers are caused by trauma, but some are associated with
keratoconjunctivitis sicca, corneal dystrophy, diabetes mellitus, Addison’s
disease, or hypothyroidism.
Corneal ulcers are extremely painful and cause severe tearing, squinting,
and pawing at the eye. Dogs frequently avoid light. Large ulcers are visible to
the naked eye as dull spots or dished-out depressions on the surface of the
cornea. Small ulcers are best seen after the eye has been stained with
Treatment: Early veterinary consultation and treatment is vital to prevent
serious complications and even loss of the eye. Medical treatment is similar to
that described for a corneal abrasion, except that ulcers take more time to
heal. Your veterinarian may recommend injecting antibiotics directly into the eye beneath the
Surgical treatment involves suturing the third eyelid or a flap of
conjunctiva over the surface of the eye to protect the cornea during healing.
Soft contact lenses and collagen shields are other methods of protecting a
damaged cornea. The advantage of a contact lens is that it can be changed
weekly to observe and treat the ulcer. Collagen shields need to be replaced
periodically because they degrade and disappear within a few days. Your dog may
need to wear an Elizabethan or BiteNot collar while the eye is healing to
prevent rubbing or pawing at the eye.
Rupture of the eye into the anterior chamber can be anticipated if the
cloudy central portion of a deep ulcer begins to clear, or the endothelial
layer protrudes like a bulging tire. This can be recognized by your
veterinarian. It is an emergency. Immediate surgery is necessary to prevent
loss of the eye.