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Diet for Cats With Cancer: Nutrition & Considerations

Written by: Ingrid King

Last Updated on February 14, 2024 by Catster Editorial Team

Diet for Cats With Cancer: Nutrition & Considerations

While cancer in cats is not as common as it is in dogs, it is still one of the leading causes of death in older cats. According to the Animal Cancer Foundation, 6 million cats will be diagnosed with cancer in the United States this year. Because cats are masters at masking illness, it is often harder to detect.

Cancer used to be a death sentence for cats, but recent advances in feline cancer research have made treatment possible in many cases. Like human cancers, early detection is vital to a successful treatment. Depending on the type of cancer, treatment options may include surgery, radiation, and chemotherapy.


Cancer changes the body’s metabolism

Cancer changes how the body metabolizes nutrients. Cancer cells metabolize glucose (from carbohydrates) and make lactate that the body then tries to convert back into glucose. This process diverts energy from the cat, feeding the cancer instead.

Cancers also convert amino acids, the building blocks of protein, into energy, which causes muscle wasting, poor immune function, and slow healing. Additionally, tumor cells have difficulty utilizing fat as a source of energy. All of this results in what’s known as “cancer cachexia,” a progressive weight loss and depletion of muscle and connective tissues.

Veterinarian explaining to woman cat medical condition
Image Credit: Nestor Rizhniak, Shutterstock

Good nutrition is critically important in cats with cancer

For these reasons, adequate species-appropriate nutrition is critically important in feline cancer patients. Unfortunately, cats often lose their appetite when they’re not feeling well. It’s important to stay on top of how much your cat is eating. Refusal to eat can ultimately be a quality of life indicator in cats with cancer.

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The optimal diet for a cat with cancer

The optimal diet for a cat with cancer is not all that different from that for a healthy cat: a diet high in quality protein and low in carbohydrates. There is not much research available on diets for cats with cancer. Many veterinarians recommend feeding a high protein, high fat, and low carb diet based on studies conducted with dogs. Omega-3 fatty acids are also recommended since they are a good source of fat and also have anti-inflammatory properties.

Many premium quality grain-free diets will meet these parameters. Alternatively, you may want to consider a home prepared diet for cats with cancer. A holistic veterinarian or veterinary nutritionist can help you design appropriate recipes.

Raw feeding is controversial for cats with cancer, and some veterinarians caution against it. “I recommend avoiding raw meat-based diets for cats that are on immunosuppressive medications like chemotherapy or higher doses of cortisone-type drugs like prednisolone,” says Andrea Tasi, VMD, a holistic feline veterinarian and owner of Just Cats Naturally.

Veterinarian giving advice on pet food to cat owner
Image Credit: goodluz, Shutterstock

It’s more important for cats with cancer to simply eat than what they eat

Even though feeding an optimal ratio of protein, fat, and carbs is ideal, this is not the time to force a diet change. While dry food may be the worst possible nutritional choice for a cat with cancer, it is an option if it’s the only thing your cat will eat.

Cats with cancer may become finicky about eating, and encouragement may be needed. Adding incentives such as freeze-dried meat treats, tuna juice, small pieces of cooked meat, or nutritional yeast can all help encourage cats who have lost their appetite. For more information, read How to Get Finicky Cats to Eat.

Featured Image Credit: Seattle Cat Photo, Shutterstock

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