Cancer in cats is unfortunately considered relatively common and more prevalent than ever before. But why?
In part, it's because cats are living longer. It's not unusual for veterinarians to see two or even three cats over the age of 15 every day. They're the beneficiaries of great home care, advanced nutritional research and modern veterinary medicine. Read on to learn about the signs to look out for and how to give your kitty the best possible oncology care if she ever needs it.
Defining Cancer

What exactly constitutes a cancer? Contrary to popular opinion, not every ugly mass, growth or cat tumor qualifies.
Cancer is best defined as a disorder caused by the uncontrolled division of abnormal cells. A cancer may originate in one single tissue of the body, but it can sometimes affect faraway organs as it spreads, typically through the circulatory and lymphatic systems by a process vets refer to as metastasis. For example, cells dividing in a tumor that starts in your cat's ear could travel through the bloodstream to her liver.
Most Common Cat Tumors
Just like in people, cancer in cats is often hereditary, which makes it more prevalent within specific genetic lines. This means that some breeds of cats can be predisposed. It also means that some cancers are more common in cats than they are in people. Here are the most typical kinds of cancer in cats:
- Lymphoma: Often associated with the feline leukemia virus, the Cornell Feline Health Center notes that this is perhaps the most common cause of cat cancer overall.
- Squamous cell carcinoma: The oral version tends to be aggressive, destructive and painful, says Cornell Feline Health Center, but lesions tend not to spread. The skin form is similarly localized and primarily affects the skin of the nose and ear tips. Ultraviolet light exposure is strongly associated with this type of cancer.
- Fibrosarcoma or soft tissue sarcoma: This is a cat tumor that forms in a muscle or connective tissue of the body, writes Wag!. It can appear just about anywhere on your cat's body.
- Mammary tumors: Cornell Feline Health Center notes that these are considered relatively common in intact cats, but among cats spayed before puberty (like the vast majority of our household companions) they're deemed very rare.