Royal Canin Nutritional Information

Royal Canin Nutritional Information

Cancerous conditions are relatively common in giant breeds, especially osteosarcoma (© Psaila).

Key Points to Remember:

Nutritional Management of Dogs with Cancer

• The preferred energy sources are fat and protein, at the expense of carbohydrate, which is highly valued by cancer cells. The main principles of formulation are the same as diets that meet the requirements of sporting and working dogs.
• Fat helps to increase the energy concentration of the food, which is necessary in anorectic or cachexic patients.
• Enriching the long-chain omega 3 fatty acid (EPA-DHA) content in the food helps the dog benefit from the anti-neoplastic properties of EPA-DHA.
• A high-protein diet helps combat muscle wasting during cancer cachexia. The amino acids that play an important role in slowing the progression of the tumor, include:
  - Arginine, which favors nitric oxide production
  - Glutamine, which has immunemodulating actions
  - Branched chain amino acids (e.g., leucine, isoleucine and valine), which help combat cachexia.
• Antioxidant supplementation (e.g., vitamins E and C, b-carotene, polyphenols, selenium) is of major interest in preventing cancer. However, based on our knowledge at this time, antioxidant supplementation should be avoided during chemotherapy or radiation therapy so that the efficacies of these therapies are not compromised.
• The palatability of the food is key in anorexic and cachectic dogs.

Focus on: Branched Chain Amino Acids

Among the essential amino acids, leucine, isoleucine and valine constitute a category of their own called the branched chain amino acids (BCAA's). The dog is incapable of synthesizing adequate amounts of these three amino acids, so dietary intake is needed to meet daily requirements. The concentration of these three amino acids in the blood is very dependent on dietary intake.

Figure 10. Chemical formula of branched chain amino acids.

Valine, leucine and isoleucine represent at least one third of the essential amino acids constituting muscle proteins and are the only amino acids that are initially degraded by muscles. These three amino acids are unique among the essential amino acids because they are able to undergo reversible transamination to enrich the organism's nitrogen pool.

Valine, leucine and isoleucine are able to stimulate the synthesis of proteins and slow protein degradation in muscles. This property has been specifically attributed to leucine, as it proves as effective as a mixture of the three BCAA's.

In rats, stimulation of protein synthesis by leucine follows a dose-response type curve. This stimulation is produced at very low leucine concentrations, identical to those observed in the blood just before a meal. In older rats, much higher leucine concentrations are needed to obtain maximum stimulation (INRA, 2002). The sensitivity to leucine intake is therefore reduced. This loss of sensitivity may explain the absence of increased muscle protein synthesis after meals in aging subjects.