The cause of cancer in pet animals, just like in people, is largely unknown. There are certain breeds that tend to get certain types of cancers more often than others, such as large and giant breed dogs who get bone tumors. There are also environmental factors, such as exposure to the sun that may be associated with increased incidence of cancer. Unfortunately not enough is known about the cause of cancer to prevent it.
Some of the causes of cancer include the following:
Environmental substances
Age
Heredity or congenital factors
Vaccinations
Trauma
Viruses
Other unknown causes (idiopathic)
Not all these things amy cause cancer in pets. For example, cats are particularly susceptible to vaccination-site tumors; dogs are not. Some tumors and cancers occur in intact dogs and cats, whereas a pet who is spayed or neutered has little or no chance of having the same types of cancer. However, spaying or neutering you pet doesn’t guarantee your pet won’t develop cancer.