Cryosurgery for cancer in cats and dogs.

Cryosurgery for Cats and Dogs with Cancer

Introduction
Cryosurgery (also called cryotherapy) refers to a technique that uses extremely cold temperature produced by substances
such as liquid nitrogen to kill abnormal or cancer cells. It is usually used to treat relatively small external tumors such as
those on the skin. For treatment of easily accessible tumors such as those in the anus, the pet will typically require only a
local anesthesia. Other sites such as the eyelid may require sedation and sites such as oral cavity might require general
anesthesia.

How does cryosurgery work?
The pet's hair will be first shaved near the area of the tumor to be treated, followed by taking a sample for biopsy and
removal of a majority of the tumor to minimize the tumor volume for freezing and to shorten the procedure time. The
freezing of the tumor will be performed either by spray or by a cryoprobe. The procedure duration can vary from 30
seconds to a few minutes, depending on the site and the tumor type/size. The veterinarian will typically also freeze a layer
of normal cells surrounding the tumor to make sure that no cancer cells are left behind.

The pet may experience mild discomfort immediately after the procedure which usually resolves within 12 hours. The frozen
tissue may swell and change color, occasionally oozing a small amount of blood or serum. It will form a scab withing a few
days and although the site may look infected, antibiotics are not always necessary. The scab typically falls off withing 3
weeks, leaving a small hairless spot.

What tumors are typically treated with cryosurgery in cats and dogs?
While a variety of different tumor types have been treated with cryosurgery, there are four specific tumor sites in pets that
have been treated with successful results - eyelid tumors, perianal tumors, oral tumors and skin tumors.

Sources:

Withrow Stephen J, and David M. Vail. Small Animal Clinical Oncology. St Louis: Saunders Elsevier, 2007.
Morrison Wallace B. Cancer in Dogs and Cats: Medical and Surgical Management. Baltimore: Williams&Wilkins, 1998.