Diet plays an important role in the endurance potential of canine athletes. The Alaskan sled dog might be considered the ultimate canine athlete, sometimes pulling a sled more than 1,000 miles in subzero temperatures. Providing a well-balanced diet is essential to meet the special needs of dogs in such nutritional-stress situations. Not only should the diet fed to these dogs be high in protein, but it also should be high in fat, which serves as the major energy source for exercising muscles.
A high-fat diet can help muscles burn fat more efficiently. During sustained exercise, fatty-acid oxidation is the primary source of energy for the muscles. Increasing the efficiency of fat metabolism spares the body’s use of carbohydrates, and because most dogs have in excess of 10 to 50 times more energy stored in fat than in muscle glycogen (carbohydrate), this might boost the animal's exercise performance.
IAMS™ studies1 have shown that in trained sled dogs as in ordinary dogs, exercise performance was enhanced by switching from a low-fat to a high-fat diet (from 25 to 65% of calories from fat), as indicated by increased:
When dogs were switched back to a low-fat diet, all of these criteria decreased to their previous values.
These results indicated that by increasing the availability of fat stores and capacity to metabolize fat for energy, a high-fat diet promotes exercise endurance in canine athletes.
1 Reynolds AJ, et al. “The effect of diet on sled dog performance, oxidative capacity, skeletal muscle microstructure, and muscle glycogen metabolism.” Recent Advances in Canine and Feline Nutritional Research: Proceedings of the 1996 IAMS International Nutrition Symposium. Carey DP, Norton SA, Bolser SM, eds. Wilmington, OH. 1996. 181–198.
Dog-food products described as light, lite, or low calorie must meet specific calorie levels set by the Association of American Feed Control Officials (AAFCO), while dog foods named “less” or “reduced calorie” must show a percent reduction in calories as compared to a product in the same moisture-content category. The following table shows the guidelines as set by AAFCO for both dog and cat foods for determining whether a product can use the term “light.”
| Food Texture | Moisture Content | Dog Foods Maximum kcal ME/kg | Cat Foods Maximum kcalME/kg |
|---|---|---|---|
| Dry | less than 20% moisture | 3,100 | 3,250 |
| Semi-Moist | between 20 and 64% moisture | 2,500 | 2,650 |
| Canned | 65% or more moisture | 900 | 950 |
Like light versus reduced-calorie foods, lean or low-fat dog-food products must meet specific fat levels set by AAFCO, and less-fat or reduced-fat dog-food products need to show a percent reduction in fat as compared to a product in the same moisture category. AAFCO guidelines for dog and cat foods with “lean,” “low fat,” or similar words are shown in the following table.
| Food Texture | Moisture Content | Dog Foods Maximum % Crude Fat | Cat Foods Maximum % Crude Fat |
|---|---|---|---|
| Dry | less than 20% moisture | 9 | 10 |
| Semi-Moist | between 20 and 64% moisture | 7 | 8 |
| Canned | 65% or more moisture | 4 | 5 |