Found in the blood and in the fluid that surrounds cells, sodium maintains the cellular environment and prevents cells from swelling or dehydrating. Sodium is also important for maintaining proper nerve and muscle cell function.
Meat, poultry, fish, and eggs are good sources of sodium.
Sodium also might be included in commercial pet foods in the form of table salt (sometimes listed on the ingredient panel as salt). Salt is an important palatant for animals, as well as for people.
The Association of American Feed Control Officials recommends that dry dog foods contain at least 0.3% sodium for both maintenance and to support normal growth and development. This is the minimum recommended levels.
While high sodium intake might cause increased thirst and water consumption, the extra sodium is excreted in the urine of dogs. Healthy dogs are able to consume diets with higher sodium levels than those found in most commercial pet foods without increased blood pressure or gain in body water.
Therefore, the sodium level in commercial pet foods is not a cause for concern in healthy animals.

A veterinarian might recommend decreasing a dog's sodium intake if the animal has some types of kidney, liver, or heart disease, in order to help decrease high blood pressure or the accumulation of excessive body fluid.
Although older dogs might be more likely to develop these diseases, healthy older dogs do not require a low- or reduced-sodium diet.
The sodium level in our dog foods is appropriate for a healthy dog. The sodium content in these foods is balanced in proper proportions with energy, other minerals, vitamins, fats, proteins, and carbohydrates.
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.