From the Archives of Cat Fancy: Enjoy this all-access pass to cat history from the pages of the oldest living cat magazine. This content remains in its original form and reflects the language and views of its time. Health and behavior information evolves and only the most current advice should be followed.
Excerpted from CAT FANCY magazine, 1966, Issue 1
Rodent ulcer of the lip in cats shows as an eroded area on the edge of the lip. At first it appears as a small pinkish area along the edge of the lip. The center of this area has a reddish, raw look to it. Only when the ulcer becomes large does it cause any apparent discomfort to the cat or cause lack of appetite. The area of the lip immediately surrounding the ulcer later becomes thickened so that the affected portion of the lip may protrude slightly.
Upon turning the lip outward, the center of the area on the edge of the lip appears to be eaten away. Most of these are seen on the upper lip opposite the points of the lower canine teeth, but may occur on other portions of the lip as well.
The cause is thought to be mechanical irritation from the tongue or form the opposite tooth, below or above. Local medication is of no value, as the cat will lick it off almost instantly.
This type of condition is not malignant. However, there is a type of cancer which appears in the same area. The practiced professional eye can usually distinguish between the two, but in cases of doubt, a biopsy might be in order to obtain a more definite diagnosis.
A few of these ulcers will heal spontaneously, but many that are not treated promptly will continue to erode the lip away. This can cause disfigurement of the lip. Even with treatment, there may be some disfiguring of the lip, depending, of course, upon how much tissue was eroded away before healing finally began.
There are several types of treatment, one or all of which may be needed to get healing started. Silver nitrate applications may be used in tractable cats without resorting to general anesthesia. Applications of silver nitrate may have to be repeated at intervals until the area is healed. Along with this, corticosteroids and antibiotics are usually administered, the injectables usually being the most satisfactory.
Tranquilizers or general anesthesia may be necessary if the cat will not submit to treatment without excessive struggling.
A second type of treatment, always used under general anesthesia, is electrocautery with the electric needle. Thorough scraping of the area may or may not be needed in conjunction with this. Corticosteroids and antibiotics are also given with this therapy.
A third type of treatment is radiation (x-ray) therapy, which is effective in many cases where the first two methods of treatment have failed to promote healing in the ulcers.
The last method is surgical removal of the affected area. This requires that a certain amount of normal tissue surrounding the area be removed. With this method there is always a certain degree of permanent disfigurement because of the amount of tissue removed.
Your veterinarian, experienced in the treatment of this rather difficult condition, should see your cat, in order to start treatment, as soon as any suspicious raw or ulcerated area appears on the edge of the lip. Small, new areas will usually respond to treatment quite rapidly. If these areas are permitted to go untreated, they become quite large. Response to therapy may be slow and difficult, besides having the possibility of a disfigured lip once the ulcer has healed.