An adult dog needs at least 18 percent protein on a dry matter basis, or 45 grams per 1,000 calories, and a puppy or a pregnant or nursing dog needs at least 22.5 percent, or 56.3 grams per 1,000 calories, under the AAFCO nutrient profiles that complete foods are built to meet. Those are floors, not targets, and going far above what your dog needs does not buy extra health. This post covers where the numbers come from, how to convert what is on your bag, why the quality of the protein matters more than the headline percentage, and where the evidence runs out, so a higher number on the bag stops being a reason to pay more.
The numbers and where they come from
AAFCO's Dog Food Nutrient Profiles set the crude protein minimum at 18.0 percent dry matter (45.0 g per 1,000 kcal) for adult maintenance and 22.5 percent dry matter (56.3 g per 1,000 kcal) for growth and reproduction.1 Tufts nutritionist Cailin Heinze gives the same figures per 100 kcal: 4.5 g for adults and 5.63 g for puppies and pregnant or nursing dogs.2 The profiles draw on the National Research Council's 2006 nutrient requirements report, which gives recommendations based on physical activity and stage of life.3
Note what these are. They are the least protein a food can contain and still be called complete and balanced. They are not a recommendation for your dog, and almost every food on a shelf exceeds them. The question is by how much, and whether it matters.
Converting the number on your bag
The guaranteed analysis lists crude protein as fed, with the water still in it. To compare a kibble to a can or a freeze dried food, take it to dry matter: divide protein by (100 minus moisture), then multiply by 100.
- Kibble, 26 percent protein, 10 percent moisture: 26 divided by 90, times 100, is 28.9 percent dry matter.
- Canned, 8 percent protein, 78 percent moisture: 8 divided by 22, times 100, is 36.4 percent dry matter.
- Freeze dried raw, 40 percent protein, 5 percent moisture: 40 divided by 95, times 100, is 42.1 percent dry matter.
The better basis is grams per 1,000 kcal, because a dog eats calories, not cups. A dense, high fat food can have a respectable dry matter percentage and still deliver less protein per calorie than a leaner one. WSAVA and Tufts both ask companies to state nutrients on an energy basis for this reason, and a company that can do it on request is telling you something about itself.2 The rest of the label walk through is in how to read a dog food label.
Is more protein better?
Not by itself. Heinze puts it plainly: feeding a diet higher in protein than pets need does not result in any health benefits.2 In a healthy dog, the extra is burned for energy or excreted, which is why she also says excess protein is unlikely to be harmful. The exception is disease. For some conditions, kidney disease among them, excess protein can worsen the disease process, and that is a conversation for your vet, not a bag label.2
Where high protein does earn its keep is in weight loss, where a protein rich food helps a dog lose fat rather than muscle; Heinze notes high protein diets are often used for pets on weight loss plans.2 If that is your situation, how to help your dog slim down safely goes into the numbers.
So the honest answer to "how much" is: comfortably above the minimum, from good sources, matched to the dog's life stage. A 30 percent dry matter food is not better than a 26 percent food because of the four points. It might be better because of what the protein is made of.
Quality beats quantity
"Crude protein" is a nitrogen measurement. It counts protein your dog can use and protein your dog cannot use the same way, which is why the number alone cannot tell you much. What the dog actually needs are ten essential amino acids: arginine, histidine, isoleucine, leucine, lysine, methionine (with cystine), phenylalanine, threonine, tryptophan, and valine.4 A food is only as good as its supply of the scarcest one.
Animal proteins tend to carry all ten in usable proportions, but Heinze cautions that even within animal sources there is a lot of variation in protein quality, and that plant and animal proteins can be combined to fill the gaps.2 On a label, this is the case for named species over generic "meat," and for a food whose first protein is an animal rather than pea protein or corn gluten meal. Under The Truva Standard, that is the first check, named animal protein first, and the one we weigh most heavily. We would rather sell a 28 percent food with named meat first than a 36 percent food that gets there on legume concentrates. The freeze dried foods in our freeze dried raw collection sit at the high end of the protein range because they are mostly meat, organ, and bone, which is also why they cost what they cost.
Puppies, seniors, and athletes
Puppies need the growth minimum, 22.5 percent dry matter, and the food should say "growth" or "all life stages" in its adequacy statement. Large breed puppies have a separate calcium issue that matters more than protein; see large breed puppy food requirements.
Seniors are where I have to be straight with you. The old advice was to cut protein for older dogs; the current view among veterinary nutritionists leans the other way, toward keeping protein up to hold muscle. I did not find a source I trust that gives one number for healthy seniors, and dogs with kidney or liver disease are a different case entirely. Ask your vet, with bloodwork in hand.
Working and sporting dogs mostly need more calories. Because protein is set per 1,000 kcal, a dog eating more of the same food is already getting more protein. The food does not need to change unless the dog is losing condition.
When to call the vet
Call before moving an older dog or any dog with a history of kidney, liver, or urinary problems onto a high protein food; a blood panel first is cheap insurance. Call if a dog on a high protein diet starts drinking or urinating much more than usual, loses weight without trying, or goes off food. And if your vet recommends a protein restricted diet for a diagnosed condition, that advice outranks anything on this page.
Sources
- AAFCO, "Proposed Revisions to AAFCO Nutrient Profiles (Dog Food Nutrient Profiles)," 2014, adopted 2016. aafco.org (PDF)
- Cailin R. Heinze, Tufts Petfoodology, "Pondering Pet Protein: How much protein should my pet get?," 2019. Petfoodology
- National Research Council, "Nutrient Requirements of Dogs and Cats," 2006. nationalacademies.org
- Deborah E. Linder, Tufts Petfoodology, "What Nutrients are Essential for My Pet?," 2023. Petfoodology