TUMORS OF THE SKIN

Tumors are abnormal growths of cells. Tumors affecting the skin or the tissue just under the skin are the most commonly seen tumors in dogs. Skin tumors are diagnosed more frequently than other tumors in animals in part because they are the most easily seen tumors and in part because the skin is constantly exposed to many tumor-causing factors in the environment. Chemicals, solar radiation, and viruses are just some of the things that can cause skin tumors. Hormonal abnormalities and genetic factors may also play a role in the development of skin tumors.

All of the various layers and components of skin have the potential for developing distinctive tumors. Distinguishing a tumor from an inflammatory disease can sometimes be difficult. Tumors are usually small lumps or bumps, but they also can occur as hairless, discolored patches, rashes, or nonhealing ulcers. Because skin tumors are so diverse, identifying them should be left to a veterinarian.

Tumors may be benign or malignant (cancerous). Malignant tumors can spread and cause harm to the animal. Distinguishing a benign tumor from a cancerous tumor requires specialized knowledge and laboratory equipment. A veterinarian can perform a fine needle aspiration of cells or a biopsy (which removes a small amount of tissue from a tumor) for evaluation.

Treatment for a particular tumor depends largely on the type of tumor, its location and size, and the overall physical condition of the dog. For benign tumors that are not ulcerated and do not impair the dog’s normal routine, treatment may not be necessary. This may be the most prudent option, especially in aged dogs.

The Merck/Merial Manual for Pet Health. Copyright© 2007 by Merck & Co., Inc.,
Whitehouse Station, NJ, USA. All rights reserved.