A form of skin cancer affecting the tips of the ears, eyelids or nostrils of cats is common. Cats with white or light-colored fur in these parts of the head are affected; the condition is rarely found with dark pigmentation.
The ear-tips, eyelids and nostrils are usually only lightly covered with hair, so that they are unprotected from the carcinogenic ultra-violet rays of the sun. The disease usually does not develop until the cat is middle-aged.
At first the margins of the ears become reddened and thickened and are often covered with a light-colored scab. The lesion appears to heal during the winter months only to reappear in a more extensive form the following summer.
The inflammation of the tissues causes the cat to scratch its ears until the surface bleeds. When this blood-loss occurs over a long period the animal may become quite anemic.
Eventually the thickening of the skin gives way to a red irregular shaped growth which quickly increases in size and bleeds profusely if knocked. The whole head may be spattered with dried blood.
Growths on the nostrils start with a crusty brown elevation of the skin. Unfortunately the cat often starts to lick the area with its rough spikey tongue and soon erodes the tissues.
Inflammation of the tissues within the nostrils produces a thin, watery discharge. This stimulates the cat to lick its nose even more vigorously, so that the erosion proceeds to a point where the animal must be destroyed.
Treatment of the early stages of these carcinomas is possible using radiation from implants of radium. This can only be carried out in specially equipped centers and is usually beyond the realm of practicality.
Fortunately the tumors involving the ears do not readily spread to other parts of the body. Removal of the diseased portion of the ears to a point where the new margin is protected by the longer hair at the base of the ear is the most practical solution and usually prolongs the life of the cat by many years.
Rodent ulcers are localized thickened areas occurring usually on the lips in which the surface becomes eroded to form a shallow yellowish crater. The precise cause of the condition is not known by one school of thought believes that these areas have become hypersensitive to sharp fragments of the cat’s tongue embedded in the surface of the lips.
These dense, thickened areas are composed of aggregations of one type of white blood cell, the eosinophil. Rodent or eosinophilic ulcerations can occur in other parts of the body. They are sometimes seen on the hard or soft palate in the mouth.
Areas of the cat’s body that are constantly licked, such as the backs of the legs and abdomen, sometimes develop rodent ulceration. This seems to confirm the theory that the skin in these areas develops a hypersensitivity to keratin fragments from the cat’s tongue.
Treatment is not specific and is not always successful. Injections of anti-inflammatory drugs directly into the ulcer usually give at least temporary relief. Progesterone hormones have also been used, as well as various ointments containing antibiotics and steroids.
Rodent ulcers can be the forerunner of a cancerous process, so that early treatment of the condition is essential if this sequel is to be prevented.