While out on a walk, my dog sometimes stops to eat grass. I've always wondered why, and whether or not I should be concerned. During my dog’s annual checkup, I asked the vet about it and he said it was normal. That was a relief and yet somehow unsatisfying, so I decided to poke around the Internet for some more thoughts on this behaviour.
Some articles conclude that maybe the dogs just like the taste or feel of grass in their mouths or stomachs. That is kind of cute, but I was hoping for a more evolutionarily significant explanation.
Upon further investigation, I found out that eating grass is not only common in dogs, but has also been reported in their ancestors, the wolves, as well as other relatives such as coyotes and foxes.
What seems weird about dogs eating grass is that they can’t actually digest the cellulose that makes up most of the grass, which means that grass might not qualify as food for dogs. The term for eating things that aren't food is pica. However, i'm not sure whether or not eating grass should actually fall into that category since it might enhance the conditions for the microbiome in her guts. And the fibre in the grass might act as a laxative. Grossology alert: I have seen some strands come out the butt of my dog, but she still seems to poop alright when she has not been eating grass. A variation on this argument is that grass can help purge intestinal parasites. That is not a pleasant thought and not a common issue with pet dogs these days.
Grass may contain nutrients they don't get from dog food, such as folic acid, that would be accessible if the grass cells get broken open. They are more likely to eat grass if they haven't had a meal recently. Still, the suggestion that they require nutritional supplements is annoying when I think about all money I spend on what is supposed to be nutritional, balanced dog food. That is probably a whole other discussion.
Some suggest that grass somehow makes dogs feel better if they have an upset stomach. My dog seems otherwise fine when she is eating grass. Related to this is a common response that eating grass might actually induce vomiting to get rid of what is bothering the dog, but this does not seem to be the case. My dog does not throw up after eating grass and it also seems rare among dogs. It is, however, common among cats, so maybe that was the source of confusion. Cats also have the habit of hacking up hair balls, but I don’t want to get too off track. My dog has thrown up at other times, but that seems to have more to do with my mother-in-law giving her too many fatty table scraps.
So I still don’t know why my dog eats grass, but I have not found evidence that I need to be worried unless she eats sawgrass or something doused with toxins. The City of Vancouver, where I live, does have by-laws against using pesticides or herbicides for cosmetic reasons and I usually keep my dog to the public boulevards.
What is your experience with dogs eating grass?