The Importance of Protein

By Timothy Brill

Dogs need protein. That's because this component of many foods has numerous functions in your dog's -- and your -- body. It is best known for supplying amino acids that build hair, skin, nails, muscles, tendons, ligaments, and cartilage. Protein also plays a key role in producing hormones and enzymes that help to regulate daily, basic functions.

The protein in dog foods can be supplied by animal sources, plant sources, or a combination of the two. Common animal-based protein sources used in pet food include chicken, lamb, fish meal, and beef. Common plant-based protein sources used in your pet's food include corn-gluten meal and soybean meal.

Understanding your dog's food needs
Even though some dogs are fed plant-based diets, your dog is not an herbivore. It's an omnivore.  That means your furry friend is a critter that eats both animal- and plant-based foods.

The body structure of your domestic dog is similar to that of its carnivorous ancestors and relatives, which include wolves, coyotes, foxes, and jackals. These animals are all meat-eating machines. Their teeth and digestive systems are designed to chow down on animal flesh. Consider the following:

• Your dog possesses the enlarged carnassial teeth that carnivores are named after. These teeth are efficient at digging into and holding prey, skills that were essential for survival in the wild.
• Your pet's gastrointestinal tract is simple and does not have the capacity to digest large amounts of plant products.

In addition, high quality animal-source proteins contain all the essential amino acids your dog needs, whereas some plant-based proteins may be deficient in certain essential amino acids. So although your dog is classified as an omnivore, it is best fed as a carnivore.

Research findings
Recent studies have examined how the type of protein in a diet affects the body composition of adult and senior dogs.

In this study, dogs were fed diets with varying amounts of protein from chicken and corn gluten meal. Their body composition (muscle versus fat tissue) was then analyzed. Additionally, levels of key blood and muscle proteins were measured.

Compared with dogs that were fed a diet with 100% chicken protein, dogs that consumed foods with decreasing levels of chicken and increasing levels of corn gluten meal had:

• Decreased lean tissue
• Increased body fat
• Decreased levels of blood proteins routinely used as markers of superior nutritional status

This was independent of the overall dietary protein level -- 12 or 28% -- which was also examined in each of the four test groups.

As your dog ages, its body composition and muscle-specific proteins decline. Therefore, another study looked at the differences that became evident when elder pooches consumed a 32% protein chicken-based diet, a 32% protein chicken and corn gluten meal diet, or a 16% protein chicken-based diet.

Senior dogs that were fed the 32% chicken protein, chicken-based diet had better body composition and a muscle-specific protein pattern that was identical to what was measured in healthy young adult dogs. However, those results were not seen in either of the other two diets.

Protein and Your Dog
Feeding your dog a diet with primarily animal-based protein sources helps to do the following:

• Maintain your dog's muscle mass
• Reverse some age-related changes in skeletal muscles in senior dogs
• Enhance the long-term health and well-being of adult and senior dogs

The bottom line is good-quality, meaty dog foods that will have your dog licking its chops and wagging its tail. At the same time, you can smile with confidence, knowing that you've fed your loyal friend what it craves and what its body needs.