The rate of cancer among dogs and cats is similar to the rate of cancer among humans. Cats seem to get cancer a little less frequently than humans while dogs seem to develop cancer slightly more frequently than humans. For most species, the chance that a pet will contract cancer goes up with age. For example, cancer is most common in pets that are 10 years old or older. Among dogs aged 10 or more, just under half of the deaths are due to cancer. However, even young animals can develop cancer; age is not the only factor involved in cancer development.

This chapter covers the general aspects of cancer in pets. Individual cancers and their treatments are covered in the chapters on specific body systems. For example, the description of melanoma and other skin cancers in dogs and cats can be found in the chapters on skin disorders for those species (see Cancer and Tumors: Common Cancers in Domestic Animals).

Last full review/revision July 2011