Most people know someone who has had cancer. Can pets get cancer, too?
Unfortunately, dogs and cats and other small animals can be diagnosed with cancer. The incidence increases with age.

According to the American Veterinary Medical Association, cancer accounts for almost half of the deaths of pets over 10 years of age. Dogs get cancer at roughly the same rate as humans while cats get fewer cancers.

The uncontrolled, abnormal growth of cells or tissues in the body results in a tumor. The tumor can be benign or malignant. Benign tumors do not grow aggressively, do not invade the surrounding body tissues and do not spread throughout the body. On the other hand, malignant tumors grow rapidly, invade the tissues around them, and spread or metastasize to other parts of the body.

Just as in people, early detection of a tumor in your pet is critical. Regular veterinary wellness checkups are a must. Tumors can be suspected on the basis of a pet’s medical history and physical exam. Additional tests such as radiographs (x-rays), blood tests and ultrasound (sonogram) exams may be necessary to confirm that a tumor exists.

A biopsy (taking a tissue sample from the tumor for examination under a microscope) is usually needed to confirm the diagnosis and determine if the tumor is benign or malignant. Additional biopsies of other tissues (i.e. lymph nodes) may be necessary to determine how far a cancer has spread.

Some common types of tumors in pets are:

• Skin – very common in older dogs and often benign; less common in cats but usually malignant
• Mammary Gland (Breast cancer) - 50 percent of all breast tumors in dogs and 85 percent in cats are malignant; rodents are highly prone to breast cancer; early spaying of female pets reduces the risk of mammary gland tumors
• Mouth – common in dogs, less common in cats; signs include bleeding, odor or difficulty eating
• Nose – tumors may develop in both dogs and cats; signs include bleeding from the nose, breathing difficulty, chronic sneezing, or facial swelling
• Lymphoma – common in dogs, cats, hamsters, and ferrets; signs are one or more enlarged lymph nodes in the body
• Testicles – rare in cats and common in intact dogs
• Abdominal tumors – common but difficult to diagnose early; signs include weight loss or abdominal swelling
• Bone – most often seen in older large breed dogs, rabbits and rodents, rare in cats; signs include persistent pain, lameness and swelling in the affected area.

Treatment varies depending on the type of cancer. Therapies include surgery, chemotherapy, radiation, cryosurgery or freezing, hyperthermia or heating, and immunotherapy. Patients will often receive a combination of these therapies.

Your pet’s overall health is important. Your veterinarian may recommend dietary changes to help your pet respond better to treatment or to help prevent weight loss or gain that may occur during treatment.

Your veterinarian can discuss the best treatment option(s) for your pet and any risks and side effects.

Pain management is another important part of treatment. The majority of cancers can be managed while a few cancers can be cured. The goal is to decrease the spread of the cancer and prolong your pet’s comfort and life as much as possible.

Your veterinarian may refer you to a cancer specialist. Dr. Kimberly Reeds at OSU’s Veterinary Hospital is a board-certified oncologist. She has completed all the requirements to become a diplomate of the American College of Veterinary Internal Medicine, Specialty of Oncology.

The success of treatment depends on many factors with early detection being key. Schedule your pets for regular wellness veterinary visits.

This column is provided by the faculty of the OSU Boren Veterinary Medical Teaching Hospital. The large volume of questions does not allow us to directly respond to specific email questions so please watch for your answer in the column. Email your questions for the column to This e-mail address is being protected from spambots. You need JavaScript enabled to view it and watch for your answer.

Sources: www.avma.org and www.petcancerawareness.org