Causes and Prevention of Cancer in Dogs

Source: PetWave, Updated on July 16, 2015

Causes of Canine Cancer

Medical science has not yet discovered the precise causes of the various types of cancer, despite intensive research in both the animal and human realms. Domestic dogs are susceptible to many different types of cancer. These include lymphosarcoma, osteosarcoma, soft tissue sarcomas, mast cell tumors, hemangiosarcoma, oral melanoma and mammary neoplasia, among many others. Each of these can present in a number of ways, with varying frequencies and degrees of severity. Some dog breeds are predisposed to developing certain types of cancers. Certainly, sun exposure can contribute to development of melanoma in dogs as in people. Breast cancer in dogs is much more common in intact females, as testicular cancer is in intact males. Unfortunately, it just is not possible to identify a “cause of cancer” given the current state of medical knowledge.


Little is known about how to prevent cancer in companion animals. Once the underlying causes of the various cancers are ascertained, prevention will become more realistic. We do know that spaying or neutering can reduce the risk of testicular and mammary gland cancer in domestic dogs.

Special Notes

Early diagnosis of cancer always improves the prognosis. Surgery, radiation and chemotherapy are available at specialized veterinary hospitals to treat cancer in dogs. With prompt diagnosis, aggressive treatment and ongoing management, including pain management and dietary support, many dogs with cancer go on to live long, comfortable and relatively normal lives.

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Cancer in dogs is defined by the uncontrolled transformation of normal cells into abnormal ones, which usually form masses, invade nearby tissue, and ultimately spread.

Learn more about: Cancer