Cancer is a common disease of dogs and cats. Advances in cancer therapy have resulted in increased survival time for many veterinary patients. Despite these advances, malnutrition remains a common problem in these patients. Cancer-associated malnutrition occurs as a consequence of an imbalance between the nutritional needs of the patient, the demands of the tumor, and the availability of nutrients in the body.

Cachexia is a specific form of malnutrition characterized by loss of lean body mass, muscle wasting, and impaired immune, physical, and mental function. Cancer cachexia is a clinically important problem in dogs and cats. The healthcare team must be able to identify cachexia and begin proper nutritional management as early as possible.