Lumps and Bumps

by Kevin Fitzgerald, DSVM

Text Copyright the American Kennel Club, Inc., 2006. No portion of this article may be reproduced without permission of the copyright holder. Reprinted with permission from AKC Family Dog, May/June, 2006.
To subscribe: http://www.akc.org

My dog, a 12-year-old Terrier, has a variety of lumps and bumps on his skin. They don't seem to hurt him, but how worried should I be?

Old dogs (and old people) can develop a variety of skin growths. These can range from cysts, to warts, to foreign objects, to infections, to benign tumors, to malignancy. A cyst is a usually well-defined accumulation of degenerative skin products (such as oil, hair, or discarded skin). These structures usually stay superficial and do not penetrate the skin. Warts are skin growths caused by a family of viruses in dogs and people. Infections such as granulomas and pyogranulomas are generally circumscribed areas of inflammation infiltrated by white blood cells. "Pyo" refers to granulomas that produce pus. Foreign objects (such as,wood, plant material, or metal splinters) may set up a raised local area of reaction.

Anytime a skin lump ulcerates or bleeds, it hecomes serious and should he examined. Benign tumors are usually encapsulated and well defined, and do not metastasize or migrate to other areas of the body via the lymphatic system or the blood. Malignant tumors are generally much faster growing, much less well defined, and readily spread to distant areas of the body, where they start to grow.

The diagnosis of cutaneous lumps and bumps is entirely dependent upon history and examination-including evaluation of lymph nodes and distant sites such as the lungs. Lesions must he examined to ascertain their size, shape, localization, depth, appearance, and consistency, and whether they are attached, freely moving, or ulcerated. Diagnosis is obtained through fine needle aspirates, incisional biopsy, and possibly regional lymph node aspirates and X-rays. Tissue samples are sent to labs, where veterinary pathologists confirm the diagnosis. Based upon this tissue diagnosis, your veterinarian can make an appropriate plan with regard to the treatment of the lump. Prognosis depends upon what the lump is, but early detection and concrete diagnosis are essential.

Even for very malignant growths, more and more effective therapies are being developed. It is never acceptable to take a wait-and-see attitude toward any growth without first obtaining an aspirate or biopsy read by a pathologist and obtaining a cellular diagnosis. Check your dog often. Have any lumps or humps examined by your veterinarian.