Protein is one of the most important components of dog foods.  The quality of protein sources can vary greatly and not all protein sources are used by the body to the same degree.  When purchasing a dog food, the first 3 ingredients should be from animal sources.  This is a characteristic of a high quality pet food.

What are the animal sources of protein?

Protein can come from the meat (poultry, beef, fish, lamb, duck, and rabbit), meat by-product, meat meal, and meat by-product meal.  Meat by-products and meat by-product meals are less expensive and less digestible than meat or meat meal. Below is an explanation of the animal protein sources.

Meat includes the clean combination of flesh, skin, nerve and blood vessels, overlying fat, and possibly bone.  There are no feathers, heads, feet, or entrails.  Meat has a high water and fat content.  This may place meat as the first ingredient on the ingredient list as ingredients are listed in descending order according to weight…water and fat increases the weight of the meat.  But this would contributes little to protein and may even be a more substantial source of fat in the food, which increases palatability.

By-products are secondary products and includes clean parts not used in human food such as bone, lungs, spleen, liver, ligaments, blood, fat trimmings, stomach, intestines, head, and feet. Nutritional quality varies.  Hands and feet, if included, are lower in nutritional value but the nutrient rich intestines or organs may compensate for this.  Super-premium, natural and organic varieties do not usually use by-products in their foods.

Meal is a common ingredient in dry foods.  It is produced by rendering the meat…the process that separates fat and removes water.  Bacteria, viruses, and parasites are killed by high temperatures.  Then the meat is ground or reduced in particle size.  For example, chicken meal is the dry, ground, whole chicken exclusive of head, feet, entrails, and feathers.  Bone may or may not be included.  When meat meal is included in foods they are high on the ingredient list because of the low moisture and fat content.

By-product meal is the same process of producing meal from meat except by-products are used instead.