Picking the best dog food for dogs is often a headache for owners. There are many factors that need to be considered and too much contradictory information out there.
The current dog food marketing trend is to tout meat as the first ingredient in the diet and to downplay the amounts of carbohydrates.
Many brands claim to be “grain-free dog foods” and contain mostly meat proteins, with the promise this will deliver superior nutrition, saying that all grains should be avoided (this is not true, however).
But how important is meat as the main ingredient in dog food, actually? In this article I’ll explore the science and facts about protein sources in dog food, and help you determine which protein sources have the best quality.
Meat – A Marketing Gimmick?
Years before the American Association of Feed Control (AAFCO) and National Research Council (NRC) were formed, commercial dog foods were unregulated and many diets performed poorly.
Cheap canine diets could be made inexpensively from only plant products and they often delivered poor nutrition for dogs.
In order to separate themselves from these low quality dog food brands, bigger companies chose the advertising route of claiming their products contained meat.
The message stuck and almost all dog food companies today will mention how much meat their product contains.
But the truth is, some dogs will do better with higher levels of animal protein, while others can do just fine on plant-based proteins or mixtures of the two.
How Much Protein Do Dogs Need?
Most commercial dog foods today probably feed more protein than a normal healthy adult dogs or puppies need. Deficiencies are more detrimental to health than excesses are.
Studies show that most healthy animals can handle excessive protein .
Any protein eaten that isn’t used for metabolic processes is likely burned for energy or stored as fat.
An all meat diet is extremely deficient in nutrients for dogs and will lead to many nutritional diseases, such as nutritional hyperparathyroidism.
Dog food labels can be somewhat deceiving. Many companies will claim “meat as the first ingredient” as a benefit to feeding their food.
However, ingredients are listed in descending order by weight. Meat is heavy since it is mostly water. This is why we consider it as a big factor in our reviews of dog foods.
A diet with an ingredient list of chicken, corn, wheat, and soy will probably contain more protein from those protein rich grains than from chicken as the first ingredient. This isn’t problematic unless the diet isn’t nutritionally balanced.
Adult dog food protein content is typically in the range of 20-35% which is appropriate for most healthy dogs . Where the protein comes from isn’t as important as the balance of essential amino acids.
Balance of Essential Amino Acids
Protein is made of essential amino acids, and there is a specific ratio of these essential acids necessary for optimal canine nutrition.
There are hundreds of ways to achieve this balance, whether with plant based proteins, meat based proteins, or a combination of both.
The term ‘essential’ means that the animal cannot make this amino acid on their own, it must be consumed . Essential amino acids are found in meat and from various other non-meat sources.
What is more important is that the diet has been balanced by experts in canine nutrition, and that the diet performs well during diet trials and in real life.
Research has shown that domesticated dogs have adapted to digesting and utilizing a more starch based diet than their ancestors .
In fact, dogs can even be adequately fed on a vegetarian diet .
One study found that when fed exclusively a meat free balanced diet, working sled dogs maintained important healthy blood cell parameters .
We are, of course, not advocating a vegetarian diet. Meat will always contain a better ratio of those essential amino acids than plant based protein sources.
Plant protein sources, such as soy and corn will be incomplete and must be supplemented with complimenting amino acid sources, or be supplemented with synthetic sources .
Alternative Protein Sources
Ingredients that can be rich sources of protein besides meat include protein rich grains such as corn or wheat, eggs, soy, legumes like peas and lentils, beans, mycoproteins found from fungi, and some dairy products.
Highly grain based diets will often be lacking lysine. These diets are often paired with soy products, which are rich in lysine.
Eggs and dairy are deficient in the essential amino acid taurine, which is crucial for cats, and less so for dogs, but will still need to be supplemented in order to be balanced.
In addition to meeting specific nutrient levels established by the AAFCO, diets rich in non-meat sources of protein are best evaluated by passing diet trials.
Just because the nutrients are there doesn’t guarantee they can be absorbed or assimilated adequately .
Some plant based proteins can be poorly digestible, or may be too high fiber for adequate digestion. Some plants contain a component called phyate, which is a phosphate that can prevent the absorption of nutrients in the intestines.
Diet trials are costly. They require that the research dog is fed exclusively the diet in question and undergo blood testing and physical examinations by veterinarians to ensure the diet doesn’t cause any deficiencies.
Assessing Protein Quality in Dog Food
Most meat used in dog food is left over from manufacturing meat used for human consumption. This makes assessing the quality of these ingredients very difficult.
The claim human-grade or human-quality meat have no legal definition per AAFCO.
For anything to be ‘human-grade’ all ingredients must be edible to humans and the product must be manufactured, stored and packaged according to federal regulations for human food.
This is impractical in the pet food business and thus claiming an ingredient is ‘human-grade’ can be misleading and even misbranding.
AAFCO definitions for such meat sources as chicken as ‘flesh or skin with or without accompanying bone, derived from parts or the whole carcass.’ Beef is defined as ‘clean flesh from muscle, tongue, heart, diaphragm, or esophagus, with or without skin sinew, nerve and blood vessels.’
These definitions allow enormous variation in the source of meat from the actual animal. This also doesn’t take into account how the meat is handled and under what conditions. Current dog food labels are unable to convey this information regarding meat quality.
Choosing a brand from a reputable company that regularly uses diet trials to prove the adequacy of their diets is probably more important than the listed meat content of the food on the label.
Well-respected dog food companies with millions of research dollars invested in pet nutrition and board certified veterinary nutritionists on staff are more likely to deliver a diet with good quality proteins than an obscure company with meat as the first ingredient.
On a more microscopic nutritional level, assessing protein quality is better defined. A quality protein is one that has no limiting amino acids and is complete.
Protein quality is also affected by its digestibility. Studies show protein listed on labels doesn’t necessarily correlate with quality .
Obviously different animals and even different breeds within the same species, will have different essential amino acid requirements.
Therefore it is impossible to extrapolate protein quality from one animal to another, or from humans to dogs, for example.
Final Words on Meat in Dog Foods
Meat as the main ingredient in dog food isn’t as important as many advertising tactics will make it out to be. Dogs require protein in their diet, but can thrive on protein sources other than meat.
Meat may provide the most complete balance of amino acids, but alternate sources of protein can be part of a nutritionally balanced diet.
What is more important than protein coming from meat, is that the combination of amino acids is complete, either by combining complementing proteins or supplementing.
In terms of protein quality, from a macroscopic level, quality is very difficult to assess based off pet food labels alone.
From a microscopic level, quality proteins are those that are most complete, and a complete set of amino acids can differ from animal to animal and even among breeds.
This can make it seem like pet owners have little control over knowing what they are feeding their dogs.
The best way to ensure a diet contains quality ingredients that are well-balanced is to select a diet from a reputable company devoted to furthering knowledge in canine nutrition.
The diet should be manufactured on site and under the expertise of board certified veterinary nutritionists. Ideally the diet is tested using AAFCO standardized diet trials that ensure dogs thrive when being fed this diet.
Remember not all dogs do well on the same protein sources. It may take some trial and error to find the diet that your makes your dog look and feel healthiest.[toggle title=”References“]
- Humbert B1, Bleis P, Martin L, Dumon H, Darmaun D, Nguyen P. Effects of dietary protein restriction and amino acids deficiency on protein metabolism in dogs. J Anim Physiol Anim Nutr (Berl). 2001 Aug;85(7-8):255-62.
- Wannemacher RW Jr, McCoy JR. Determination of optimal dietary protein requirements of young and old dogs. J Nutr. 1966 Jan;88(1):66-74.
- R. Glenn Brown. Protein in dog food. Can Vet J. 1989 Jun; 30(6): 528–531.
- Axelsson E1, Ratnakumar A, Arendt ML, Maqbool K, Webster MT, Perloski M, Liberg O, Arnemo JM, Hedhammar A, Lindblad-Toh K. The genomic signature of dog domestication reveals adaptation to a starch-rich diet. Nature. 2013 Mar 21;495(7441):360-4. doi: 10.1038/nature11837. Epub 2013 Jan 23.
- Lisa P. Weeth. Vegetarian Diets. Marjorie L. Chandler, DVM, MS, MANZCVSc, DACVN, DACVIM, DECVIM-CA, MRCVS University of Edinburgh
- Brown WY1, Vanselow BA, Redman AJ, Pluske JR. An experimental meat-free diet maintained haematological characteristics in sprint-racing sled dogs. Br J Nutr. 2009 Nov;102(9):1318-23. doi: 10.1017/S0007114509389254. Epub 2009 Jun 1.
- Hegedüs M1, Fekete S, Solti L, Andrásofszky E, Pallós L. Assessment of nutritional adequacy of the protein in dog foods by trials on growing rats. Acta Vet Hung. 1998;46(1):61-70.