Everything You Need to Know About Cancer

By: Suzanne Brown, DVM

TVMA Member
Belton, TX

Published February 2016

Cancer! What a scary word to hear from your veterinarian. For many pet owners, it is surprising to learn our furry companions suffer from many of the same types of cancers as we do.

The word “cancer” means a particular type of cell in the body has reproduced itself in an unnatural and uncontrolled manner. Some cancers manifest themselves in the form of a mass of abnormal cells called a tumor, while others affect cells in the blood or lymph systemA network of organs, lymph nodes, lymph ducts, and lymph vessels that make and move lymph from tissues to the bloodstream. The lymph system is a major part of the body's immune system.. The causes are varied, as are the treatments and prognoses. More serious types of cancers can spread or metastasize to other locations within the body.

How is Cancer Diagnosed?

Cancer may be diagnosed in a variety of ways. Unfortunately, there is no single blood test for cancer. Each individual cancer is diagnosed in a specific way. Sometimes the diagnosis is simple and straightforward; other times, many tests are necessary to diagnose your pet’s ailment.

Many times a lump that is easily felt on the skin surface prompts your veterinarian to test it for cancer. Often, this means inserting a small needle into the lump to withdraw a few of the cells and examine them under the microscope. Other times, vague symptoms such as excessive fatigue or looking pale may prompt your veterinarian to draw blood to check for cancers of the blood. Some cancers may be seen only with imaging such as X-rays or ultrasound. In these cases, an aspiratematter that has been drawn from the body by aspiration or biopsy may be needed. In almost all cases, cells from the actual cancer must be examined microscopically to know what type of cancer it is and to develop a treatment plan.

How is Cancer Treated?

Treatment varies depending on the type of cancer. In general, treatment falls into one of three broad categories.

Surgery: A tumor can often be removed surgically and sent to a pathologist to determine the type of cells and whether any cells have been left in the body. Sometimes your veterinarian will remove nearby lymph nodes to see whether they have been infiltrated with cancer cells. Surgery can provide a complete cure for some cancers and no further therapy is needed.

Chemotherapy: The word chemotherapy strikes fear in many people’s hearts due to their experiences with human medicine. However, most cancer specialists or oncologists who work on pets have different goals than those who work on people. The primary goal of veterinary chemotherapy is to extend good quality of life. If a particular medication is likely to result in severe side effects with little chance of success, it is not likely to be chosen for your pet.

Your local veterinarian may be able to administer some types of chemotherapy. In fact, some come in pill form and can be given at home. Other types of medicine are usually administered in a specialist’s office, where the appropriate equipment is available to ensure the safety of both the pet and the specialists who provide the medication. Nearly all types of chemotherapy require close monitoring to watch for the development of side effects.

Radiation: Most people are familiar with radiation from learning about cancer treatments for people. Radiation therapy involves aiming a beam of special light at a specific location on the pet’s body to help eradicate cancer cells. This therapy is only available at specialized clinics, usually in larger cities and universities.

Radiation is usually an adjunct treatment, meaning it is often combined with other forms of treatment. In some cases, the goal is to eradicate any remaining cancer cells in the area treated. In other cases, the goal may be to decrease the size of the tumor and reduce pain.

What is My Pet’s Prognosis?

The prediction for chance of recovery or prognosis depends on the type of cancer, how aggressive it is and its location, among other factors. Some types of cancers may be cured with treatment, especially those that have not spread to other locations. Other types will never be cured but may be put into remission for long periods of time, during which the pet enjoys a good quality of life. Some cancers are known to be very aggressive or deadly; in those cases, treatment is often palliative, aimed at alleviating pain and ensuring a good quality of life for whatever time remains.

Suzanne Brown, DVM, is a graduate of Texas A&M College of Veterinary Medicine who lives in Belton, Texas. Dr. Brown practices at Belton Small Animal Clinic and Central Texas Mobile Veterinary Ultrasound.