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The Daily Vet by PetMD

The Daily Vet is a blog featuring veterinarians from all walks of life. Every week they will tackle entertaining, interesting, and sometimes difficult topics in the world of animal medicine – all in the hopes that their unique insights and personal experiences will help you to understand your pets.

Best Food for Pets with Cancer

2 min read

Nutrition can play a significant role in the management of dogs and cats with cancer, a predominant illness and killer among pets. But how?


Although the ideal nutritional requirements for pets with cancer remains unknown, we do know that these animals show signs of alterations in the metabolism of carbohydrates, fats, and proteins, and that changes in the metabolism of these nutrients will often precede any clinical signs of disease and/or cachexia. Therefore, general dietary recommendations for pets with cancer typically consist of a combination of:


  • Small amounts of complex carbohydrates (crude fiber levels > 2.5% of dry matter)
  • Minimal quantities of rapidly absorbed simple sugars
  • High quality but modest amounts of digestible proteins (30-35% of dry matter for dogs and 40-50% of dry matter for cats)
  • High amounts of unsaturated fats (>30% of dry matter)
  • Omega-3/DHA essential fatty acid supplementation — consult with your veterinarian for appropriate dosages


Consult with your veterinarian as this can often be achieved through commercially available pet foods.


It is very important to keep in mind that additional research is necessary before making sweeping generalizations regarding the ideal diet to feed a pet with cancer. The optimal dietary requirements will vary based on individual patients’ needs, their type of cancer, and also the presence and severity of concurrent diseases (e.g., diabetes or hyperthyroidism). Many owners are Internet savvy and a quick Google search using the terms "diet, pets, and cancer," returns thousands of websites containing a tremendous amount of information. Unfortunately, most of it is unproven, over-interpreted, and not evidence based.


One of the most important thing I always stress to pet owners is that it’s never a good idea to implement any diet change and/or addition of supplements or nutraceuticals at the same time their pet is scheduled to be starting chemotherapy and/or radiation therapy, as we want to limit the number of variables that could cause adverse side effects. Once the pet has started on their treatment plan — as long as they are doing well — that is the time to consider any kind of a diet modification. Important considerations to make when thinking about any kind of change would be to serve foods that are highly bioavailable, easily digestible, and highly palatable with a good smell and taste, in order to avoid food aversions and encourage appetite.


Dr. Joanne Intile