Skin Biopsy in Dogs

By Krista Williams, BSc, DVM, CCRP; Tammy Hunter, DVM; Ernest Ward, DVM

A biopsy is one of the more common diagnostic procedures performed in dogs. Skin biopsies provide valuable insight into the type of cells in an abnormal area of skin or a skin growth and whether the growth poses a more serious health threat to your pet.

What is involved in a skin biopsy?

Most skin biopsies are performed on a suspicious skin growth or on an area of skin that has failed to respond to treatment.

In many cases, the area to be biopsied is numbed with a local anesthetic. In some cases, depending on the area involved or the nature of the patient, it may be necessary to give the patient a sedative or general anesthetic. Either the entire mass or a small section of skin is removed and submitted to a veterinary pathologist, who will perform a histopathology analysis (examine the tissues under a microscope).

The pathologist will attempt to determine the nature of the lesion, identify the type of cells and their relationship to each other, as well as any evidence of malignancy (presence of cancer cells). Most skin biopsies are very small and require few sutures (stitches). If you need to provide any home care to the biopsy site after your dog returns home, your veterinarian will explain this in detail.

"Veterinarians are particularly concerned about lumps or masses that appear suddenly or grow rapidly..."

When should my dog have a skin biopsy?

Any suspicious skin lesion or any area of poorly healing or abnormal skin should be biopsied. Veterinarians are particularly concerned about lumps or masses that appear suddenly or grow rapidly, as these are characteristics associated with malignant skin tumors. Additionally, skin that is chronically inflamed or irritated, or has an unusual color or texture should be biopsied.

What does a biopsy tell us about my dog's skin?

Skin biopsies are beneficial in large part because they tell us whether we should be concerned about a lesion. A biopsy provides information about the nature of the abnormality, and will differentiate between infections, allergic skin disease, autoimmune skin disease, and tumors - benign or malignant. By determining the nature of the abnormality, your veterinarian will be able to determine the most appropriate treatment of the condition. Finally, a skin biopsy will allow your veterinarian to determine the prognosis for the condition so that you will know what to expect during the course of the disease.

How long does it take to get the biopsy results?


In most cases, your veterinarian submits the biopsy samples to a veterinary laboratory, where a board-certified veterinary pathologist will evaluate them. It usually will take one to two weeks for the samples to be properly processed and examined, although results can sometimes be obtained faster. During the time you are waiting on the results, be sure to monitor your dog carefully for any new skin lesions or changes in existing lesions. If you observe any changes, report them to your veterinarian as soon as possible. Certain skin diseases such as immune-mediated skin disease can change rapidly or certain types of tumors such as mast cell tumors can worsen or even spread after skin biopsy.

Skin biopsy is a relatively simple, painless procedure that can speed recovery and improve quality of life for many patients. If you observe any abnormal skin on your dog, be sure to notify your veterinarian, who will help you determine the most appropriate treatment for your pet.

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