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.
Nutrients such as protein, fat, vitamins, and minerals are important players in the skin and coat health of dogs. To understand the role of these nutrients, it is necessary to start by understanding skin and hair.
The purpose of skin and hair is to block things from leaving (such as water or heat) or entering (such as viruses and bacteria) the body.
The hair coat is composed almost entirely of protein. If the animal's diet doesn't contain adequate protein quantity and quality, hair may fall out, or become dry, weak and brittle.
Skin is made up of squamous cells, flat cells tightly packed together. These cells have tough membranes that are composed of proteins and fats. Without proper amounts of these nutrients, cell membranes weaken, allowing water to escape and bacteria and viruses to enter more easily.
Proteins are found in both animal-based and plant-based ingredients. Animal-based proteins contain all the essential amino acids dogs need, whereas plant-based proteins may contain only some essential amino acids. Animal-based proteins help dogs achieve optimal health.
Fats can also be found in both animal-based and plant-based ingredients. They are incorporated into skin cells as fatty acids. There are two essential fatty acids for skin and coat health. Linoleic acid maintains skin and coat condition in dogs. Without enough linoleic acid dogs may experience dull, dry coat, hair loss, greasy skin and increased susceptibility to skin inflammation.
Both of these essential fatty acids are omega-6 fatty acids and are found in animal tissues like chicken fat. Linoleic acid is also found in some vegetable oils, such as corn and soybean oils.
Most commercial dog diets contain more than adequate amounts of omega-6 fatty acids. Because these fatty acids can be converted to compounds that increase susceptibility to skin inflammation, it is important to balance the amount of omega-6 fatty acids in the diet with omega-3 fatty acids, which reduce susceptibility to inflammation.
Omega-3 fatty acids are found in oils from fish and some plants (canola and flax).
IAMS research has found that combining fat sources in the diet at a ratio of 5-10 omega-6 fatty acids to 1 omega-3 fatty acid results in excellent skin and coat health.
Vitamins and minerals are essential for the development of healthy skin and hair coat. The best way to provide these nutrients is through a complete and balanced diet containing appropriate amounts of essential vitamins and minerals rather than through supplements.
| Vitamin or Mineral | Importance to Skin and Coat Health |
|---|---|
| Vitamin A | Necessary for growth and repair of skin |
| Vitamin E | Protects skin cells from oxidant damage |
| Biotin | Aids in the utilization of protein |
| Riboflavin (B2) | Necessary for fat and protein metabolism |
| Zinc | Necessary for fat and protein metabolism |
| Copper | Involved in tissue pigment and protein synthesis |
Diet is often believed to be a factor when changes in skin and coat condition are noticed. The most common causes of these changes, however, are season and life stage.
As cold weather approaches, most dogs grow a thick coat to help keep heat in and cold air out. As the weather begins to warm up, they shed the thick, heavy coat.
Most puppies are born with soft fuzzy hair, but as they age, a coarser coat grows. Pregnant or lactating dogs also may experience a change in coat condition or hair loss. And, as with humans, the hair on dogs may thin out and become coarser and white as they reach their senior years.