Nutrition for Pets with Cancer – Part I
Kara M. Burns, MS, MEd, LVT, VTS (Nutrition)
Cancer is one of the most common causes of nonaccidental death in pets. Pet owners understand that their four legged family members can be diagnosed with cancer, as can their human family members. Cachexia is a syndrome characterized by progressive weight loss that is oftentimes accompanied by anorexia. Body wasting in pets with cancer is also known as cachexia. Unlike weight loss seen in pets with simple starvation or an unwillingness to eat, cachexia is distinguished by a loss of fat tissue in conjunction with body muscle tissue. As a result of the cancer disease process, cachexia is seen in pets as severe weight loss, reduced food intake, and systemic inflammation. Additionally, significant loss of mineral content in the bones can also be seen contributing to the overall weakness found in many pets with cancer.
Body wasting from a cancer diagnosis is also reported to affect a high percentage of human cancer patients. In fact, cachexia is reported as the cause of death in approximately 20% of human patients with cancer. The diagnosis of muscle wasting in both human and animal patients is complicated by the fact that malnutrition occurs long before it is ‘seen’ in human or animal patients. Therefore, if a pet is suspected of having cancer the veterinary team should consider that malnutrition is occurring in that specific pet.
Therapeutic Strategies
The optimal therapy is to cure the underlying cancer; obviously, this is not always possible. In veterinary medicine therapeutic strategies generally include management of anorexia, nutritional support/supplementation, and providing omega-3 fatty acids.
Ensuring the Pet is Eating
Nutritional counseling should be a part of the pretreatment plan for all patients. The veterinary team will help owners understand the importance of measuring how much food their pet is eating and have a plan for maintaining nutritional support throughout the cancer treatment. This may include simple strategies to increase consumption initially (i.e., quiet and comfortable eating area, remove the E-collar from the animal, etc.) which may progress to tube feeding if necessary.
Nutrition
Obviously, pets with cancer need to be fed and certain nutrients may provide benefits to combat the changes the body is undergoing. Proper nutrition can be key to managing cachexia through the proper provision of calories, protein, fat, and carbohydrates. Specific nutritional recommendation should consider the stage of cancer, the pet’s energy needs, current and past nutritional status, and ability or willingness to eat.
The caloric distribution in the food should highlight calories obtained from fats and proteins, rather than carbohydrates, since glucose (carbohydrate) is the preferred fuel for tumor cells in body wasting pets with cancer. Whereas, fatty acids and amino acids are not preferred nutrients for cancer in pets. The goal is to feed the pet and starve the tumor cells.
Omega-3 fatty acids, especially those found in certain types of fish and fish oil (eicosapentaenoic acid [EPA], docosahexaenoic acid [DHA]), are important nutrients to consider for animals with cancer.
Supplementation with EPA and DHA has been shown to help prevent cachexia and metastatic disease processes.
Protein in the pets’ diet should be highly digestible and go above levels normally used for adult animals, to help offset the pet’s body wasting.
Since cancer cells like to use glucose (carbohydrate) for energy, the veterinary team will suggest a carbohydrate with a lower glycemic index; this will provide a slower release of carbohydrate generated glucose into the pets’ blood stream than would those with higher glycemic indexes. Barley, sorghum, and corn have much lower glycemic indexes and would be beneficial to pets with cancer. Fermentable fibers, such as beet pulp also count as carbohydrates, but are not used by the tumor cells.
Semi-elemental nutrition provides nutrition in small absorbable forms. The nutrients are made up from the building blocks of proteins, carbohydrates, and fats. In other words, the proteins are free amino acids, peptides, and/or hydrolyzed protein fractions. The fat source is from fatty acids. The carbohydrate sources are mono-, di- and trisaccharides. Semi-elemental nutrition provides easier digestion and rapid absorption of nutrients, designed to support the critical systems of the body. EmerAid® HDN™ formulas are semi-elemental diets specifically for cats and dogs and are a great nutritional strategy for pets with cancer and resulting muscle wasting. EmerAid® formulas offer many options for feeding a pet with cachexia. This nutritional formula can be fed through a feeding tube, added to the pet’s food, or even as a calorically dense ball of nutrition.
Summary
Pet owners and veterinary team members must recognize and understand body/muscle wasting in pets with cancer. It is important to ensure the pet is receiving proper nutrition to help manage muscle wasting from cancer as well as to ensure balance between the nutritional needs of the patient, the demands of the tumor, and the availability of nutrients in the body. Feeding strategies should be aimed at alleviating muscle wasting in pets suffering with cancer.
