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Lumps, Growths and Cancer

As our pets age, they can develop a variety of lumps, growths and cancer. Many of these are unsightly and are usually benign. But some can grow out of control and become cancerous. Nevertheless, all growths should be brought to the attention of your veterinarian; particularly if there is a sudden change in color or size.

What causes lumps, growths and cancer to occur? Just as in humans, our pets stand an increase likelihood of development of unsightly growths as they age.

There are many types of growths that can occur on the skin of our pets. You will find some of the more common ones listed below.

Some growths, such as warts, are a result of a virus that tends to occur in all age dogs on their heads and bodies. Warts are benign firm “bumpy” growths. Warts should be removed if they are irritated, bleed continuously or if they grow on the eyelid margin where they may rub against the eye.

Sebaceous cysts are often confused for growths, when in fact they are oil-producing glands that can become clogged and as a result enlarged. They range in size from mosquito-bite size to an inch or more in diameter. They often have a semi-soft feel to them as well as irregular margins. Sebaceous cysts contain a whitish to gray greasy paste-like combination of oil, bacteria and cells. Occasionally they can open up and ooze on their own; but will usually fill back up. Sebaceous cysts should be removed if they become messy or are constantly irritating.

Histiocytomas usually occur in young dogs. They are extremely rare in cats. They often are raised red, inflamed, circular and possibly ulcerated. These masses are usually solitary and rarely metastasize. Most of these masses will spontaneously regress within 4-6 months; yet most owners opt to have them removed.

Lipoma Lipomas, (often called fatty tumors), begin as soft squishy growths that are benign that can become cancerous and infiltrative over a period of time. Lipomas are lumpy accumulations of fat deposits that are slow growing. They can become very large! If large lipomas make a pet uncomfortable or interfere with its range of motion, it should be removed.

Cancer occurs when growths grow at an abnormal rate causing changes on the cellular level. These changes can be the result of trauma or mutations to the cell. Masses can become cancerous as they outgrow their blood supply. The prevalence of cancer in veterinary medicine is on the rise as a result of greater longevity of our pets. Often the single most important prognostic factor for successful treatment for cancer is early detection. In general, survival rates for patients diagnosed with extensive disease are much lower than those for patients diagnosed with smaller tumor burdens. So have your pets seen sooner than later!

So how is a lump identified and named? No growth can be definitively diagnosed without histopathology (a microscopic evaluation of the growth at the cellular level). This can be accomplished via several means:

  1. Fine Needle Aspirate - only allows for a very small sample size to be obtained for evaluation. This method is not accurate because of the very limited tissue sample size collected and often gives clients a false sense of security about the growth. The larger the growth, the less accurate this method of testing.
  2. Biopsy - a larger portion of the mass is submitted for evaluation. A biopsy involves taking a section of the growth. It is recommended to take a representative sample; or
  3. Growth Removal - the best method because the entire mass is submitted for evaluation. It also allows for determination of whether the mass was removed in its entirety.

Once it is determined what the lump, growth or mass is, a course of action can be determined as to the best way to proceed with treatment. This includes routine monitoring for possible changes in its size and color as well as surgical removal, radiation and chemotherapy.