What You Need to Know About the Protein in Your Pet’s Food

Ken Tudor, DVM
Published: March 24, 2015
What You Need to Know About the Protein in Your Pet’s Food

Your pet food does not contain the meat that you think it does. And it does not contain the amount of meat you think it does. That is because the official definition of “meat” for pet food is different from your perception of “meat.”

The “first ingredient” rule for judging pet food ingredients is misleading and not an accurate measure of the amount of “meat” in your pet’s food. It is no wonder that so many pet owners hop from food to food trying to find one that will agree with their pet’s digestion.

What is the Meat in Pet Food?

In order to make pet food affordable, pet food makers use meat scraps for protein, no matter what the brand or advertising claims. The Association of American Feed Control Officials (AAFCO) designates what can be used based on their definition of meat for various livestock species. The definitions are as follows:

Hoof Stock (beef, pork, lamb, bison, etc.)

Striated muscle but can include tongue, esophagus, diaphragm, heart and nerves, vessels, and tissue associated with those organs.

In other words, the by-products of the chest, exclusive of the lungs, are considered hoofed meat. Striated muscle that has been USDA inspected and deemed “unfit for human consumption” can also be used as meat in pet food. This is typically what pet food makers are really saying when they advertise their meat as “USDA Inspected.”

Poultry (chicken, turkey, duck, etc.)

Flesh and skin with or without bone, excluding the head, feet and entrails.

This is actually describing what is left after the breast, thigh, and leg meat have been removed. Deboned poultry is the same tissue without the bone.


Entire fish or flesh after the fillets have been removed.

Fish meat, then, is head, skin, scales, fins, skeleton, and entrails.

So what to do all of these proteins have in common and what impact does that have on your pet? They all contain connective protein. Connective proteins are ligaments, tendons or non-meat structural proteins. The gristle that you almost choked on while eating your last steak is connective protein. Connective protein is not as digestible as meat protein. It is estimated that 15-20 percent of the protein in pet food is indigestible.

This protein sits in the colon ready to be evacuated in the poop. However, the “bad” bacteria of the colon can use the indigestible protein for food. The increased population of these bacteria can cause intestinal gas, bloating, farting, and diarrhea.

With all food makers using the same type of ingredients, it is no wonder so many pet owners find that changing food doesn’t help, or only gives short term relief.

Under the cover of AAFCO’s classification of these products as “meat,” pets are not getting chicken breast, salmon fillets, or leg of lamb in their food. Advertising claims and the use of words without legal meaning, like “human grade,” does not change reality.

Next post: Exposing the myth of the “First Ingredient” Rule and exploring what alternatives pet parents have for feeding their pets.

Dr. Ken Tudor

Image: Africa Studio / Shutterstock

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