Ulcerative Keratitis, Corneal Ulcer
Keratits is an inflammation of the cornea of the eye, the tissue covering the pupil and the iris. Inflammation and swelling of the cornea with slow-healing sores is called corneal ulcer. It results from loss of epithelial tissue from the surface of the cornea due to progressive erosion and necrosis of the tissue and is usually caused by bacterial, fungal, or viral infection. When deep ulcers occur, the membrane that covers the inner surface of the cornea, may protrude through the cornea, or the ulcer can create a full-thickness hole in the cornea.
CAUSES
Corneal ulcers may result from:
- Mechanical trauma caused by clippers, whips; eyelash abnormalities; foreign bodies; exposure of cornea; eyelid diseases such as entropion.
- Infections
- Bacterial - Pseudomonas especially is serious; Moraxella in cattle.
- Viral - canine distemper, herpesvirus (Nasisse), infectious bovine rhinotracheitis.
- Fungal - numerous species, horse most commonly affected.
- Chlamydophila (gram-negative, coccoid microorganisms)
Possible complications include scarring of cornea, permanent loss of vision, and extension of infection to other ocular structures.
SIGNS
Corneal ulcers are very painful and are often accompanied by blepharospasm (spasm of the eyelids producing uncontrolled winking) and photophobia. There may be clear or pus-filled discharge from the eye(s) and swelling. Certain superficial erosions, such as in the Boxers dog, remain relatively clear.
TREATMENT
Treatment of corneal ulcers is aimed at minimizing chances for infection. Drops may be better than ointment because of less interference with healing. If the ulcers become infected, antibiotics are usually prescribed. If the ulcer is deep or is slowly healing, or there is the chance of self-trauma, it may be prudent to "bandage" the eye.
Boxer ulcers (recurrent corneal erosion)
This type of ulcers is seen mainly in Boxer dogs over 5 years of age, but is also sometimes seen in Boston Terriers, Chihuahuas, and Poodles. Boxer ulcers tend to be less painful with the cornea remaining clear. There may be excessive tear production (epiphora). Treatment consists of removing loose epithelium (mechanically or by cauterization) and then treating as a mild, superficial ulcer. Hormone therapy sometimes is recommended for spayed female and old male dogs. These ulcers are recurrent.
Go Pets America recommends seeking the advice of your local veterinarian for the most appropriate vaccination program and for the diagnosis and treatment of your pet's health problems. For vaccination requirements please contact your state and local licensing authorities.
Adapted from:
1. The Merck/Merial Manual for Pet Health
2. Comparative Ophthalmology Notes (vetmed.ucdavis.edu)
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