People choose to eat a plant-based diet for many reasons including their health, ethics, and environmental concerns. But what about our dogs? Does the same reasoning apply? It’s natural to wonder if a meat-free diet is a healthy choice for dogs.
I’ve got good news. Dogs can thrive when eating a vegetarian or even a vegan diet. Evidence is curled up at my feet.
I joke that my dog Apollo is allergic to food. When he was only nine months old, his previous owners made an appointment with me to euthanize him because he simply couldn’t eat. No matter what food they tried, he lost weight and had uncontrollable vomiting and diarrhea. Several veterinarians had tried to figure out what was wrong, but Apollo’s owners had reached the end of their resources. When I asked if I could try to diagnose and treat instead of euthanize him, they happily signed him over and wished me luck.
Long story short, Apollo has severe inflammatory bowel disease. The only food he can eat that doesn’t result in a flare-up of his symptoms happens to be vegan… in other words, it contains no animal products whatsoever. Apollo is now 8 years old, completely healthy, and weighs in at a muscular 82 pounds.
The science behind the ability of dogs to do well on a meat-free diet is quite straightforward. While their wolf-like ancestors certainly hunted to survive, modern dogs have many traits that make them more omnivorous. Research has shown that some of these physiological adaptations, such as genetic changes that allow them to better digest starch,, appear to have developed during the domestication process, but many would have been present in the wild too. An ability to make use of whatever types of foods were available would certain have increased the ability of “proto-dogs” to survive during times when game was scarce.
Of course, dogs still need protein. They are just perfectly capable of getting it from non-meat sources. Here’s why.
When dogs eat protein, their bodies break it down and then reassemble the building blocks (amino acids) into whatever new proteins the dog actually needs—for example, building and maintaining muscle or manufacturing hormones or disease-fighting antibodies. So what’s vital is that the protein in a dog’s diet contain all the “essential” amino acids that he or she needs. Essential amino acids are defined as those that must be supplied in the diet because the dog’s own body can’t make them from other amino acids.
There are 10 essential amino acids for dogs: arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.4 All of these are readily available from animal-free sources of protein.
So if you choose to feed your dog a high quality, well-formulated, vegetarian or vegan diet, have no fear. You’re doing right by your dog… and the planet.
1. Vegetarian versus Meat-Based Diets for Companion Animals. Knight A, Leitsberger M. Animals (Basel). 2016 Sep 21;6(9). pii: E57.
2. The genomic signature of dog domestication reveals adaptation to a starch-rich diet. Axelsson E, Ratnakumar A, Arendt ML, Maqbool K, Webster MT, Perloski M, Liberg O, Arnemo JM, Hedhammar A, Lindblad-Toh K. Nature. 2013 Mar 21;495(7441):360-4.
3. Diet adaptation in dog reflects spread of prehistoric agriculture. Arendt M, Cairns KM, Ballard JW, Savolainen P, Axelsson E. Heredity (Edinb). 2016 Nov;117(5):301-306.
4. Foraging and feeding ecology of the gray wolf (Canis lupus): lessons from Yellowstone National Park, Wyoming, USA. Stahler DR, Smith DW, Guernsey DS. J Nutr. 2006 Jul;136(7 Suppl):1923S-1926S.
5. AAFCO Methods for Substantiating Nutritional Adequacy of Dog and cat Foods: Proposed Revisions Edited per Comments for 2014 Official Publication. [(accessed on 14 February 2018)].