Veterinary Public Health

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Veterinary Public Health Program
313 N Figueroa St. Rm 1127
Los Angeles, CA 90012
Tel (213) 989-7060
Tel: (877) 747-2243
Fax (213) 481-2375
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Cancer in Animals

cat sitting in hallway

Cancer is seen in domestic animals, wildlife, people, and plants. Cancer is a group of diseases characterized by uncontrolled growth and spread of abnormal cells. Veterinarians are trained to use the term neoplasm for uncontrolled growth of cells. Use of different nomenclature can lead to confusion even among various health professionals. Veterinary cancers are increasingly described in the same “language” as their human counterparts. If the spread of cancer cells is not controlled, it can result in death.

Cancer is caused by both external factors (chemicals, radiation, and infectious organisms) and internal factors (inherited mutations, hormones, immune conditions, and mutations that occur from metabolism). Cancer is treated with surgery, radiation, chemotherapy, hormone therapy, biological therapy, and targeted therapy.

The spectrum of cancers seen in domestic animals is as diverse as that seen in human patients. For example, breast or mammary cancer is common in people and also seen in animals. But spaying at an early age reduces the chances of mammary cancer in pets. Experts estimate that one in eight women alive today will get breast cancer. The vast majority of breast cancer in cats is malignant while in dogs less than half are malignant.

All breeds of dogs develop cancer. But some breeds that have a higher incidence of cancer. For example, Rottweilers and Greyhounds have more bone cancer, Golden retrievers develop more cancer of the lymph nodes and Scottish terriers have more bladder cancer. Similarly the types and frequencies of various cancers in people vary by race.

Age and Cancer
The risk of cancer increases with age and most cases occur in adults who are middle-aged or older. It is estimated that one in four dogs greater than two years old will die of cancer.  Certain very popular breeds are over-represented in terms of cancer incidence and mortality.
The improved general health of pets has resulted in an increase in age-related diseases, including cancer. People see a comparable increase with age. About 77% of all cancers are diagnosed in persons 55 and older.

Early rodent studies
Many initial cancer studies involved rodents. However, they often did not adequately represent many of the features that define human cancer. Naturally occurring tumors in dogs and other animals have clinical and biological similarities to human cancers that are difficult to replicate in other model systems.  Pets with cancer could provide crucial insights into the human forms of the disease, potentially leading to better treatments and screening for tumors. Investigators at the U.S. National Cancer Institute are now studying companion animals.

Learn what cancer is, how it is diagnosed and treated, and includes the ten common signs of cancer in small animals.
See the brochures listed below.

American Veterinary Medical Association Brochures about Cancer in Animals
Cancer in Animals (English)pdf icon
Cancer in Animals (Spanish)pdf icon

Public Health has made reasonable efforts to provide accurate translation. However, no computerized translation is perfect and is not intended to replace traditional translation methods. If questions arise concerning the accuracy of the information, please refer to the English edition of the website, which is the official version.
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