A common question asked by dog owners is why their dog eats grass. This is particularly concerning to owners whose dogs eat grass and then immediately vomit.
The commonly presented explanation is that dogs eat grass to settle their stomach when it’s upset. A dog that vomits immediately after consumption of grass may very well be using grass in this way. That being said, there can be a myriad of other reasons for consumption of grass. Some dogs even seem to graze on grass.
So why do eat grass?
Dogs, as we know, are most closely related to wolves. While most breeds seem distant from their wild ancestors, they still do possess characteristics of wolves. One of these characteristics is remaining omnivores. Cats are obligate carnivores and thus primarily subsist on a diet of meat. They will occasionally eat grass for moisture or fun. Dogs on the other hand are omnivores and, like humans, prefer a diet that contains both meat and vegetables or greens.
Analysis of wolf diets done by Steve Brown who wrote Unlocking the Canine Ancestral Diet noted that wolves, while consisting primarily on a meat diet, consumed the entire prey animal – including the stomach. As their prey was typically herbivores, that meant that wolves often ate grass that their prey had eaten making grass a natural part of their diet. Thus, it isn’t at all odd that dogs may also consume and graze on grass. In fact, it may contain essential nutrients that your dog’s commercial diet may have in short supply.
Grass, particularly in the summer months, is also packed full of moisture. This makes grass a particularly appetizing snack as it is green and luscious. Dogs consuming grass for this reason may very well select specific stalks to munch on just to get a little extra moisture.
When dogs consume grass to settle a stomach, they often do throw up after consumption. There is a reasonable explanation for this. A dog hoping to settle a stomach will consume the grass rapidly which may agitate the stomach lining inducing regurgitation. If your dog appears to do this to excess, there may be an underlying health issue that ought to be addressed by a veterinarian, particularly if the dog has never consumed grass and/or is eating a large quantity and vomiting it up immediately.
In conclusion, there can be a myriad of reasons a dog may eat grass and this may or may not be a matter of concern. If your dog is consuming grass regularly and in small amounts and does not vomit after, it is nothing to be concerned about—your dog simply enjoys eating grass. You may even want to add vegetables to your dog’s diet—although they tend to prefer cooked veggies over raw. If your dog vomits after consuming grass very rapidly they may just have a slightly upset stomach and is certainly something to keep an eye on. If this behavior persists, it may be time to schedule a vet visit and make sure there is no serious underlying cause for the behavior, particularly if it’s out of the ordinary.