Q: Our 5-year-old neutered cat has had four episodes now — at about six-month intervals — consisting of a large raw area appearing in the same place on his left upper lip margin. We’ve had him treated by a vet only to have it return each time in a few months. The presence of the ulcer doesn’t appear to bother him — he eats and feels OK at the time — but it’s beginning to bother my pocketbook. Any ideas on how to keep this condition from re-occurring?

— Abby R.

A: Abby’s cat is apparently afflicted with a fairly common problem in domestic cats called rodent ulcer.

Merck’s medical manual describes it as “a well-circumscribed, erythematous, ulcerative lesion, ordinarily not painful or pruitic, usually on the upper lip of cats.”

Not a lot of money and time have been spent researching this problem, probably because it is not life-threatening — in fact, it is even self-limiting at times.

A recent article in a veterinary periodical points out that the general consensus is that feline lip ulcers — also known as lick ulcers, indolent ulcers and eosinophilic ulcers — are the result of food allergies, flea allergies or inhalant allergies — probably in conjunction with a period of resistance-compromising stress. There also appears to be an inherited, or familial, predisposition to this disorder.

The crater-like ulcers, found normally on the upper lip, usually are unilateral, but at times affect both sides, and can occasionally include the lower lip and tongue.

It also has been reported in dogs, but is considered rare.

Legend has it that years back, before any scientific studies were done on the subject, farmers believed their barn cats derived this condition from catching and eating rats and mice — hence the name “rodent” ulcers.

Today, we know there is no connection, but, as often happens, the name has persisted.

Feline rodent ulcers favorably respond to various forms of treatment including steroids (cortisone), antibiotics, laser application, cryosurgery (freezing) and surgical excision.

The best response to therapy seems to result from the oral administration of a synthetic hormone called Ovaban (megestrol acetate), but is frowned upon by some clinicians because of its suspected potential for undesirable side affects.

In short, treatment is not very specific, as the condition responds favorably to several widely divergent regimens.

Dr. Susan Little, a veterinarian with the Winn Feline Research Group, said “The most challenging aspect of treating this disorder, and preventing its recurrence, is trying to identify an underlying cause.”

As stated above, it is widely believed to be associated with an allergic reaction coupled with stress.

Defining and correcting these factors often takes a lot of patience, dedication and detective work in concert with your veterinarian.

Early intervention is important, since the longer the lesions persist, the more likelihood of permanent tissue damage.



DR. WILLIAM K. FAUKS is a retired Oklahoma City veterinarian. If you have any questions about the health of your pet, write to “Ask a Vet,” at 3142 Venice Blvd., Oklahoma City, OK 73112, or e-mail bfauks1@aol.com.

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