You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Many forms of cancer compete with the body for energy, and this problem is compounded by reduced food intake

It is well known that cancer cells grow at the expense of the animals body as they compete for available energy sources, particularly carbohydrates. Many tumours preferentially metabolise glucose using anaerobic glycolysis, and the rate of turnover of glucose has been estimated to be up to 80% greater in cancer patients than in normal patients.  Glucose is an essential energy source for several organs, including the brain, and this increased glucose utilisation shifts the body into a catabolic state, so it starts to breakdown its own body stores of energy (as fats, glycogen and proteins) to maintain blood glucose concentrations.

At the same time, appetite is often suppressed in cancer patients due to a variety of factors :

• Decreased sense of taste
• Decreased sense of smell
• A direct effect of intermediate metabolites (eg serotonin) on the satiety centre in the brain
• The presence of liver disease
• The presence of paraneoplastic syndrome - with hypercalcaemia
• Pain
• Obstruction to normal feeding by the tumour
• Side-effects of anti-cancer treatments
• Generalised weakness, depression and eventually a moribund state

The net result of increased energy utilisation with decreased energy intake is accelerated catabolism with rapid body weight loss.

Maintenance of energy intake is of paramount importance if cancer patients are to maintain homeostatic mechanisms, maintain immune-competence and respond optimally to the use of therapeutic drugs and other modalities of treatment. If necessary force feeding or tube feeding techniques (such as PEG tubes) should be adopted early in the course of the disease to prevent this vicious downward cycle of energy wastage, weight loss and generalised weakness.

Updated January 2016