Importance of Animal-Based Proteins in Dog Foods

Food For Thought™ Technical Bulletin No.23R

Innovative Research in Dog and Cat Nutrition™

Dogs Need Protein

Protein has many functions in the body, but is best known for supplying amino acids to build hair, skin, nails, muscles, tendons, ligaments, and cartilage. Protein also plays a main role in hormone and enzyme production.

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 pet food include corn-gluten meal and soybean meal.

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Why should dogs be fed a diet with animal-based proteins?

Even though they are often fed plant-based diets, dogs are not herbivores. They are omnivores, animals that eat both animal- and plant-based foods.

The body structure of domestic dogs is similar to that of its carnivorous ancestors and relatives the wolf, coyote, fox, and jackal - ideal for eating animal flesh

  • Domestic dogs possess the enlarged carnassial teeth that carnivores are named after, which are efficient for holding prey.
  • The 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 dogs need, whereas some plant-based proteins may be deficient in some essential amino acids. So although dogs are classified as omnivores, they are best fed as carnivores.

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Research findings

Recent studies by The Iams Company examined how the type of protein in a diet affected body composition of adult and senior dogs. 1

Chicken: Corn Gluten Meal

Adult and senior dogs were fed diets with varying amounts of protein from chicken and corn gluten meal, and their body composition (muscle versus fat tissue) was analyzed. In addition, levels of key blood and muscle proteins were measured.

Compared with dogs fed a diet with 100% chicken protein, dogs fed diets with decreasing levels of chicken and increasing levels of corn gluten meal had

  • decreased lean tissue
  • ncreased 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 dogs age, body composition and muscle-specific proteins decline. Therefore, another study looked at the differences between feeding senior dogs a 32%-protein chicken-based diet, a 32%-protein chicken and corn gluten meal diet, or a 16%-protein chicken-based diet.

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

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Feeding diets with primarily animal-based protein sources

  • Helps maintain muscle mass in dogs
  • Helps reverse some age-related changes in skeletal muscles in senior dogs
  • Can help enhance long-term health and well-being of adult and senior dogs.
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    1 Data on file. The Iams Company 2001.