Why has my pet developed cancer?

Why has my pet developed cancer?

All cells have the potential to develop cancer. It is in many cases a matter of chance and misfortune.

The more divisions a cell undergoes, the more probable is a mutation; therefore, cancer tends to be more common in those cells that divide more frequently and in older animals whose cells have undergone many divisions. Pets are living longer, and because cancer frequency increases with age, we are seeing more cancer cases.

"Cancer tends to be more common in those cells that divide more frequently."

In some cases, an animal has been exposed to carcinogens, factors in the environment that cause or promote cancer. These include sunlight, some chemicals and some infections.

Some animals have a greater tendency (genetic susceptibility) to cancer. Some breeds have far more cancers than others, often of specific types.

A few tumors need hormones to start growing or to enable them to persist. These tumors are classified as "hormone dependent".

Can my animal catch cancer from another animal? Can my animal transmit cancer to others?

For the vast majority of cases the answer to both questions is "No!"

Some viruses and other microorganisms can cause cancer in animals. Animals may become infected with one of these agents from their mother before or at birth, through direct contact with other animals of the same species, or through bites of 'vectors' such as fleas or ticks. Feline leukemia virus, for example, can cause cancers of the blood and lymphoid system in cats. Occasionally, an infected queen will transmit the virus to her kittens before or at birth. However, feline leukemia virus is more commonly spread by close contact with infected cats that shed the virus in saliva, urine and feces. If your cat is infected, it can pass the infection to other cats.

If your pet is infected with a specific transmissible cancer, your veterinarian will advise you of this and you must take steps to prevent your pet from infecting other animals.