Why Do Dogs Eat Grass?

My papillon, Kitsune, is the ultimate foodie!  If he thinks something is even remotely eatable, he’ll eat it!  Weather dependent, I’ve been trying to spend as much time as possible lately outside with my two dogs, Kitsune and Fenrir.  When we’re outside, I have to keep a close eye on Kitsune.  While Fenrir enjoys playing fetch and relaxing in the sun, Kit likes to try to spend a majority of his yard time grazing on the lawn!  This led me to ask the age old question.  Why, exactly, do some dogs eat grass?

Soothing an upset stomach?

While Kitsune will try to eat grass almost every time we go outside, my Alaskan klee kai Fenrir almost never does.  In fact, Fen showing any interest in eating grass has always been a sure fire sign that he’s got an upset stomach.  I’ve always heard that dogs eat grass when they aren’t feeling well, perhaps to make themselves throw up.  While Fenrir does seemingly eat grass to help sooth an unset stomach, he almost never throws up afterwards.

There seems to be anecdotal evidence that some dogs, including my Fenrir, do eat grass as a result of an upset stomach.  However, soothing an upset stomach can’t be the only reason why dogs eat grass.  My Kitsune eats grass all the time, pretty much every time he goes outside, and there’s no way he is experiencing stomachaches that often.  He’s healthy, active, and playful, with no health issues or symptoms that would indicate he is experiencing constant stomach upset.

Making up for a diet deficiency?

Another theory as to why some dogs eat grass suggests that they might be trying to obtain nutrients, or perhaps fiber, that they are lacking from their regular diet.

An interesting paper by Kang et al, from 2007, discussed the case of a miniature poodle who was reported to have consumed grass daily for 7 years.  The dog’s owner was directed to switch their dog to a high fiber diet.  After doing so, the poodle was reported to have ceased eating grass.  Although this case only discussed one single dog, it seems to suggest that, at least for some dogs, eating grass is an attempt to make up for dietary deficiencies.

I don’t think this is the case with my own dogs, however.  Both of my dogs are on a well balanced diet.  In the case of Kitsune, I actually have tried feeding him a higher fiber diet.  Doing so did nothing to curb his cravings for grass.

Instinct?

Could dogs eating grass be an ingrained instinct that goes back to their wolf ancestors?

The stomach contents of wolves have been found to contain 2-10% plant matter.  However, this plant matter is thought to mostly come from the stomachs of herbivores that the wolves eat.  But examining the stool samples of wolves has seemed to suggest that some wolves do, at least occasionally, consume grass.

For attention? Or boredom?

Yet another theory suggests that some dogs might consume grass for physiological reasons, such as to illicit attention from their owners, or because they are bored.  It may also be a nervous habit, similar to how some humans will chew on their fingernails or inappropriate objects when they are stressed.

While I can’t speak for all dogs, of course, I don’t feel these reasons resonate with my own dogs.  Kit and Fen find spending time outside anything but boring.  I usually make sure to keep them engaged when we’re outside.  We play with toys, work on training, or go for a hike.

To relieve health issues?

I haven’t come across any evidence that grass eating can help elevate health issues such as internal parasites/worms.  I have seen it suggested that this could be a cause for grass consumption, though.

Do dogs just like eating grass?

After all of that this, I think, is the most likely reason why my dog Kitsune eats so much grass.  Plain and simple, I think he enjoys it.  He seems to, often times, take great care in walking around the lawn looking for choice pieces of grass to eat.  He’s a grass connoisseur!  Anyone who knows Kit would probably agree with me.  He’s one of those dogs who is obsessed with eating and that obsession, apparently, extends to eating grass.

An individual thing!

Like most things related to dogs, there doesn’t seem to be a one size fits all answer as to why some dogs eat grass.  There are many theories as to why, including that grass eating can help relieve health issues, that they do it for attention or to relieve boredom, that eating grass is instinctual to dogs, that it can help make up for dietary decencies, or sooth an upset stomach.  The fact of the matter is that some dogs might also just enjoy eating grass! 

Comment below!  Do you have a dog that eats grass?  Why do you think your individual dog does it?

Sources:

Kang, B. T., Jung, D. I., Yoo, J. H., Park, C., Woo, E. J., & Park, H. M. (2007). A high fiber diet responsive case in a poodle dog with long-term plant eating behavior. Journal of Veterinary Medical Science, 69(7), 779–782. https://doi.org/10.1292/jvms.69.779