Cancer in Cats
Cancer is a class of diseases in which cells grow uncontrollably, invade surrounding tissue and may spread to other areas of the body. As with people, cats can get various kinds of cancer. The disease can be localized (confined to one area, like a tumor) or generalized (spread throughout the body).
Causes of Cancer
Cancer is a “multifactorial” disease, which means it has no known single cause. However, we do know that both hereditary and environmental factors can lead to the development of cancer in cats.
- Squamous cell carcinoma of the ear, eyelid or nose is a skin cancer caused by repeated exposure to the sun. White, or light colored, cats are more susceptible to squamous cell carcinoma.
- Lymphosarcoma or lymphoma (LSA), is one of the most common type of cancer in cats. Some reports estimate that 30% of all reported cat cancers are due to LSA. Feline leukemia virus (FeLV) is linked to most forms of LSA except for the gastrointestinal (GI) form. FeLV is a transmittable retrovirus that can be passed in utero as well as through saliva and direct contact. Primarily a disease in younger cats, the virus doesn’t always manifest symptoms, so it is important to have your cat tested regularly to prevent transmission and progression. There is a vaccine available for FeLV that your veterinarian can discuss with you based on your cat’s lifestyle and risk of exposure to FeLV.
The GI form of LSA (the most common form) can cause a large mass in the stomach or intestine or diffuse infiltration throughout the intestinal tract.
It is important to take your cat to your veterinarian if any evidence of disease is noted. LSA is not curable, however, most cats respond well to treatment.
Symptoms of cancer in cats may include:
- Lumps (which are not always malignant, but are always worth having a veterinarian examine)
- Persistent sores or skin infections
- Abnormal discharge from any part of the body
- Bad breath
- Listlessness, lethargy or other marked change in behavior
- Weight loss
- Sudden lameness
- Diarrhea or vomiting
- Scaly and/or red skin patches
- Decreased or loss of appetite
- Difficulty breathing, urinating or defecating
- Change in behavior
Diagnosing Cancer in Cats
If a lump is present, the first step is typically a needle biopsy, which removes a very small tissue sample for microscopic examination of cells. Alternately, surgery may be performed to remove all or part of the lump for diagnosis by a pathologist.
- Radiographs, ultrasound, blood evaluation and other diagnostic tests may also be helpful in determining if cancer is present or if it has spread.
Cats More Prone to Cancer
- Though cancer can be diagnosed in cats of all ages and breeds, it is much more common in older cats.
- Certain breeds are prone to specific cancers, but cats with white ears and heads are particularly susceptible to skin cancer.
Ask your vet if your cat falls into specific at-risk categories.
- Keeping your cat indoors will protect her from certain skin cancers caused by repeated sun exposure and sunburn.
- Breast cancer is a common cancer for cats, but it can be avoided by having your cat spayed before her first heat cycle.
- Treatment options vary and depend on the type and stage of cancer.
- Common treatments include surgery, chemotherapy, radiation and immunotherapy or a combination of therapies. Success of treatment depends on the form and extent of the cancer and the aggressiveness of the therapy. Of course, early detection is best.
- Some cat owners opt for no treatment of the cancer, in which case palliative care, including pain relief, should be considered. Regardless of how you proceed after a diagnosis of cancer in your pet, it is very important to consider his quality of life when making future decisions.
- Some cancers can be cured, and almost all patients can receive at least some benefit from treatment. Please note that if your cat’s cancer is not curable, there are still many things you can do to make your pet feel better. Don’t hesitate to talk to your vet about your options. And remember good nutrition and loving care can greatly enhance your cat’s quality of life.
Knowing When to Consult Your Vet
Contact your veterinarian immediately if your cat shows any of the clinical signs mentioned on the list above. Should your cat receive a diagnosis of cancer, you may wish to consult a veterinary oncologist, often employed by specialty veterinary practices and teaching hospitals.