I saw a couple of mentions of this recently and thought it deserved a post. This one is going to be shorter than I’d like because I have obligations tonight, but I may come back and revise it/lengthen it.
The short story is that vegan diets for dogs are a bad idea on a bunch of fronts. Let’s explore the three main reasons that people become vegans, and whether or not they apply to dogs.
Health: People–humans–are primates. We’re omnivores, with a digestive system and endocrine system that evolved to work at its optimum fitness when being fed a diet rich in simple plant matter and some meat. We have long, complex intestines that slow down our digestive process so we get a lot out of each bite we take. We have big stomachs so we can eat larger amounts of energy-poor food like plants. We have nice wide flat teeth to grind vegetable matter and release the cell contents from the cells. We can release a lot of insulin to lower our blood sugar when we eat grains and fruits. We produce a bunch of amylase and other enzymes to speedily break down plant and seed carbohydrates. We’re behaviorally tuned to “graze,” eating throughout the day as soon as we feel even a little hungry. In every way we are tuned toward this way of living. So if we choose to remove meat from our diets, as long as we’re careful to eat lots of different types of plants and know enough about protein metabolism to make sure we’re getting all our amino acids, we can do very well and even thrive.
Dogs have NONE of these digestive tools. They are carnivores. Everything about THEIR digestive systems is developed to digest large chunks of meat and semi-whole bones. They have short, efficient intestines designed for nutrient-rich meals that must be sent through the system quickly before bacteria can build up. They have appetites that encourage them to bolt large chunks of food, and they chew only enough to make the bolus small enough to swallow (they do not ever chew things to a pulp like we do, so they do not release the contents of the plant cells so the contents can be digested and used). They do not handle sugar or blood sugar rises well. They do not produce much amylase. They are not built to eat throughout the day; their stomachs want them to eat large, concentrated meals and then fast (for up to several days).
Vegan diets for dogs do not contain the lovely leafy salads we might assume they do.
Let’s look at one ingredient list for a vegan dog diet: Wheat, Whole Corn, Soybean Meal, Quinoa and Oats Wheat Middlings, Corn Gluten Meal, Soybean Oil, Beet Pulp
Here’s another; the starred ingredients are organic: *Corn *Soybean Meal, *Whole Roasted Soybeans, *Flax Meal, (and may include one or more of the following certified organic small grains: Barley, Oats, Field Peas, Wheat, Triticale)
The second one’s pretty decent, huh? Except that the second one isn’t dog food. It’s turkey food. Cold Springs Farm organic turkey starter, same protein content as the dog food.
Dogs are not built to live on this stuff.
(Turkeys are, however, and they’re actually kind of interesting creatures, and may be a fun pet.)
Morality: Humans choose to switch to a vegan diet because they do not feel that killing other animals is right.
That’s a perfectly valid argument. However, dogs do NOT think it’s wrong to kill animals. They, in fact, wouldn’t exist if they were not extremely efficient killing machines. Dogs would rather kill animals than most other things in their lives, and in fact most of the games they play and the activities we share with them–like fetch, or herding, or tug–are just versions of behaviors they use to kill other animals.
This, for me, would be analogous to whether you have non-vegan friends, and whether their eating habits offend you. If you say “to each his own,” and don’t mind if your buddy has a hamburger while he’s sitting on your couch, you may do very well with a dog as a pet. If you have made a decision to have no animal products in your house, ever, I would recommend that you not own a carnivore, a climax predator who is, most likely, fantasizing about killing a small animal at this very second.
Ethics: Some people prefer a vegan lifestyle because of the way animals are treated on farms and feedlots.
Here you have a lot of traction with me. I have every sympathy and support for this. I would strongly suggest that you therefore make the effort to find human-grade, grass-finished or home-raised meats for your dog. I grew up in that environment; I knew tens or hundreds of small farmers. The care their animals receive, and the affection they enjoy, is exemplary. You should never feel ethically torn about supporting these small producers and their healthier, fitter, holistically produced meats.
By the way, this last is much easier to do if you feed a raw diet and source the ingredients yourself, which means the dog gets very little or no grains (which is good and much healthier for him in the short AND long run).