---

Feeding Your Pet, Not the Tumor

Nutrition plays a vital role in influencing our pet’s health, well-being, and longevity. With more variety and better canine nutrition choices being offered by manufacturers, we as owners have our job cut out for us in selecting the perfect food for our companion animal. But what happens when your healthy pet is no longer healthy – when a balanced diet just isn’t enough? What if your pet is diagnosed with cancer, is there a food that can better support your pet’s fight? For pets with certain diseases, owners may feel helpless or unable to find an appropriate diet. The more we learn about our pet’s unique condition and nutritional needs, the more selection we have to make the best choice for our pet.

What changes metabolically when a dog has cancer?

“Research has documented that dogs with lymphoma and many other malignant diseases have a significant alteration in carbohydrate metabolism.� (Burns, Kara). Tumors prefer to metabolize glucose (carbs) for energy, forming lactic acid as an end product. The patient (your pet, in this example) must then expend energy to convert the lactic acid back to glucose for its body to use – this results in energy gained by the tumor (allowing it to grow) and a net loss to the animal (causing weakness and weight loss and overall deterioration). It is recommended that diets for cancer patients contain a small amount of soluble carbohydrates – less than 25% of a food’s dry matter basis. Most manufactured pet foods contain high amounts of carbohydrates; so many pet owners will need to switch their dog’s diet upon diagnosis. This also will limit what foods will be appropriate to feed your dog.
Since studies have shown that cancer can induce long-lasting changes in canine protein metabolism, it is important that a food be of high quality, highly digestible dietary protein. It is recommended that the protein level be between 30 – 45% of a food’s dry matter for the canine patient.
The best type of diet for a canine cancer patient is one that is high in fat. Why? Many tumor cells have difficulty using fat as a fuel source, therefore the theory is that foods relatively high in fat, particularly Omega 3 Fatty Acids, may benefit dogs with cancer. Fat is where dogs derive most of their energy from a food, so by giving our pet a food high in fat we are giving our pet more of what he or she needs; unfortunately most manufactured pet foods are low in fat – another reason that a pet owner will most likely have to switch their pet’s diet upon diagnosis. This theory of ‘fat is good’ is backed up by many veterinary nutritionists and some claim that supplementing your pet’s diet with salmon oil (a source of Omega 3 Fatty Acids) may even be able to starve tumors. For example, Dr. Ogilvie states that Omega 3 Fatty Acids can actually help stop tumor growth, but suggests limiting Omega 6 Fatty Acids (like in primrose oil), which may cause cancer growths to grow faster. Salmon oil is readily available at most pet retailers and can easily be added to the pet’s food. Though owners do complain that it can give their pet fishy breath, I believe the benefits far outweigh this inconvenience as one study reveals:
“Dietary supplementation with a high level of fish oil is safe for dogs, overall….In dogs undergoing chemotherapy for lymphoma, Omega 3 Fatty Acid supplementation increased survival time, increased disease-free interval (remission), improved metabolic abnormalities, and improved quality of life.� (Burns, Kara).
Arginine, an essential amino acid, has been shown to improve immune function in cancer patients and promote wound healing, thereby making it a beneficial supplement as well. Pet foods must contain Arginine in their formula to be balanced (and approved by AAFCO), so supplementation is not as vital as with the salmon oil.

Which dog foods are best for a pet with cancer?

While some owners may choose to make a homemade diet for their pet (with the approval and advice of a pet nutritionist), others find it easier to stick with a manufactured food. After looking through 30 different dog foods’ guaranteed analysis, I was able to pick out just a few that I feel comfortable suggesting. I chose canned foods because they tend to be more palatable than dry foods and dogs with cancer tend to have little or no appetite. I’ve briefly compared the 4 canned foods that are readily available and best fit the criteria of a recommended food for a pet with cancer. These foods are balanced and safe to be fed long term and are simply suggestions, not your only choices. Comparisons are done on a dry matter basis for fair evaluation.

Canine N/D canned (Hill’s Prescription Diet for cancer patients)
     Protein 38%
     Fat 33.2%
     First ingredient: Meat by-products

Blue Buffalo Wilderness canned foods (holistic and grain free)
     Protein 45.4%
     Fat 40.9%
     First ingredient: Turkey, Duck, or Salmon based on flavor/variety bought

Merrick Before-Grain canned foods (holistic and grain free)
     Protein 40.9%
     Fat 27.2%
     First ingredient: Chicken or Buffalo based on flavor/variety bought

Nature’s Variety Instinct (grain free)
     Protein 44%
     Fat 32%
     First ingredient: Lamb, Chicken, Beef, or Duck based on flavor/variety bought


References:
Burns, Kara. “Therapeutic Foods and Nutraceuticals in Cancer Therapy.� Veterinary Technician, April 2010.

“Nutrition for the Canine Cancer Patient.� www.caninecancer.com. 2007 – 2011.

Guaranteed Analysis for commercial pet foods found at www.petco.com
Guaranteed Analysis for prescription diet found in 2005 Hill’s Key to Clinical Nutrition Handbook.