If your pet is at a healthy weight when diagnosed with cancer, don’t make changes to the dietary routine.

If your pet is obese when diagnosed with cancer, discuss with your veterinary professional team the best method to get to an ideal weight. Why?  Although obesity has not yet been linked to increased cancer risk in dogs or cats, obesity has been linked to cancer in people, so it’s a likely risk factor for pets. too.

In 2012, Tufts University’s Clinical Nutrition Service team composed of Cailin R. Heinze, DVM, MS, DACVN, Frank C. Gomez, BS, and Lisa M. Freeman, DVM, PhD, DACVN evaluated 27 “cancer diets” recommended for dogs with cancer, sourced from the internet and/or books, only to find that NONE met the minimum nutrition requirements mandated for commercial diets. (

Contrary to some claims that diet can prevent cancer in pets, Dr. Lisa Weeth, a board-certified veterinary nutritionist and author of the Weeth Nutrition blog, writes, “No dietary change or nutritional supplement has been definitively shown to prevent cancer in dogs or cats.”

According to Dr. Lisa Weeth, Weeth Nutrition Blog, “The most likely risk factors for cancer are genetics, viruses, environmental toxins, age and the neuter status of pets.”

Tufts University’s Clinical Nutrition Service team reminds pet caregivers to avoid raw-diets or treats that easily harbor food-borne illnesses such as rawhide bully sticks, freeze-dried treats, and similar products, because pets with cancer are immune-compromised and more susceptible to these infections.

Thinking about a home-cooked diet for your pet? Consult with a board-certified veterinary nutritionist before beginning a new program to be sure the plan is nutritionally sound.

A board-certified veterinary nutritionist will review your pet’s medical and diet history, evaluate the current diet, answer questions, and design a plan for you and your veterinarian to follow.

Good news: most commercial dog foods contain enough Omega-3s to support a pet’s nutrition and some evidence suggests Omega-3s have some benefit for pets with cancer.

Remember, the majority of pets do NOT experience side effects from cancer treatment, but if they do a veterinary oncologist will prescribe medication to counter the effect.