How much protein does a dog need?

I’m getting confusing answers to the question in the title. My book on cats (and it is a great book^A) compares the protein requirements of cats to dogs. The authors, Mel and Fiona Sunquist, say that dogs can survive on much less protein than cats. We know that because cats are obligate carnivores whereas dogs can survive and thrive on a vegetarian diet. They are carnivores but they tend towards being omnivores and therefore dogs can get away with only 4% protein by weight. That means that 4% of the weight of their food intake should be protein. Just to clarify that, if a dog eats a hundred grams of food four grams of it should be protein.

This figure is probably right at the bottom end of the scale of dog protein requirements. I say this because the Internet tells me that adult dogs need something in the region of 15 to 23% of protein in their diet. Puppies need more than that at about 29%, one website tells me.

Perhaps a problem is that we know that dogs have evolved from wolves and wolves are referred to as meat eating predators. However, the domestic dog has evolved from the wolf over about 20,000 years. This evolution allows them to digest plant-based starches and to survive and thrive on a wide variety of ingredients including plant-based foods and fruit et cetera. But they still need essential amino acids.

Hills, the pet food manufacturer, advise that people should focus on the quality of protein in their diet rather than the quantity. It is possible to feed your dog too much protein. For example, veterinarians caution against feeding dogs with kidney disease with a diet too high in protein.

At the other end of the scale you can feed too little protein to a puppy. They need protein for energy and to build strong muscles, bones and joints. The Association of American Feed Control Officials (AAFCO) advise that a dog’s diet should contain a minimum of eighteen percent (18%) crude protein on a dry matter basis. This means after the water has been extracted from the food. Growing puppies require a minimum of 22.5% dry matter protein by weight. Ask your veterinarian about your individual dog’s needs because it does vary depending upon a dog’s life stage and activity levels.

A. Wild Cats of the World.