A cancer diagnosis is something no one wants to hear, whether it's for us humans or our beloved pets. But cancer is a real fear, and one that increases as we (and our pets) age. In fact, it's estimated that one in five cats will be diagnosed with cancer. So while it's wonderful that our cats are living longer lives, it means an increased risk that cancer could strike. Thankfully, progress in how we understand and treat cancer means there are more treatment options available that can help ensure our feline friends are kept healthy and happy for as long as possible.
What Causes Cancer in Cats?
"Cancer" and "neoplasia" are blanket terms for when cells in your cat's body begin to divide and multiply out of control. This clump of poorly-behaved cells is a tumor, or neoplasm. Tumors can form anywhere in the body, and will look and act differently based on the original cells they came from.
Benign tumors are lumps that are growing where they aren't supposed to be or beyond the bounds of that cell type's normal territory, but that don't invade other tissues or spread throughout the body. One of the most common forms of benign tumor in cats is a lipoma, or fatty tumor. While these squishy lumps can be unsightly, they usually grow slowly and don't destroy neighboring tissue.
Malignant tumors invade and damage neighboring tissues and may also spread throughout the body. Tumor cells can break off and travel through the blood vessels and lymphatic system, forming a seed to start a new tumor elsewhere in the body. This secondary growth is called metastasis, and most commonly occurs in the lungs.
The cause of a cat's cancer is often unknown. Some cancer types may have a genetic element and be inherited, and environmental factors and carcinogens can also play a role. We do know that the feline leukemia virus (FeLV) can cause lymphoma and leukemia in cats, and that feline immunodeficiency virus (FIV) is a risk factor for developing cancer. Thankfully, your vet can test for both of these viruses, and keeping your cat indoors can help protect her from contracting them! White cats have an increased risk of developing squamous cell carcinoma, particularly on their face and ears. In very rare cases, vaccination can lead to the formation of a fibrosarcoma—but it's a small chance. The Veterinary Information Network reports that studies have found only 1 in 1,000 to 1 in 10,000 vaccines will lead to formation of a fibrosarcoma—much less than the risk of contracting one of the diseases that vaccines protect against.
Signs and Symptoms of Cancer in Cats
Potential signs of cancer in cats include:
- Bad breath or odor
- Behavior changes
- Diarrhea
- Difficulty breathing
- Drooling
- Enlarged lymph nodes
- Hiding
- Icterus (yellow appearance to skin)
- Lameness
- Lethargy
- Lumps
- Pain and discomfort
- Pale gums
- Poor appetite
- Snorting
- Sores that don't heal
- Swelling
- Vomiting
- Weight loss
Many of these signs could apply to a number of conditions, but age can be a risk factor. Senior cats are more likely to have cancer than younger cats. Any time your cat seems off, especially if it persists for several days or more, she should be examined by a veterinarian to determine what is