Why Does My Dog Eat Grass?

• Posted on Jun 6, 2019

The question as to why dogs eat grass is not a new one.  And it might surprise you to know the exact reason is not fully understood.  Nevertheless there are solid theories, supported by clinical experience and scientific studies, which can help answer this age-old question.

One good thing to know is that one of the main reasons a dog might eat grass might be because they are supposed to!  Studies have shown that almost 70% of dogs eat various plants, and of the plants they eat 78% is grass. A great majority of these dogs are younger or middle aged with no health problems.  We also know that dogs are more “omnivorous carnivores” so eating plant matter is not foreign to their nature. Therefore it is possible that a good number of dogs do this simply because it’s natural.  Nevertheless there are times when eating grass can be a sign of something more serious.

A popular misconception is that dogs eat grass because they are sick to their stomach and need to make themselves vomit.  Dogs actually have voluntary control over vomiting, and do not need to ingest grass to make themselves throw up. This does not mean that dogs who eat grass and vomit don’t have an upset stomach.  It just means they don’t need to eat grass to induce vomiting. Some dogs who consume grass have been shown to have gastrointestinal disorders such as parasites or inflammatory bowel disease. Instinctively dogs may be trying to decrease inflammation or purge parasites.  Plant fiber is known to have anti-inflammatory properties on the bowel as it passes through, as well as help purge things from body. In this way grass may soothe some discomfort caused by inflammation from parasites or other disorders.

In TCVM (traditional Chinese veterinary medicine) inflammation in the stomach and intestines is sometimes characterized as Stomach Heat.  Within this paradigm grass can be cooling and help alleviate Stomach Heat. So whether considered in eastern or western terms, eating grass can be a sign of an upset stomach, and an attempt to relieve it.  The cause of the upset may be an infection or something short term that requires treatment, but it could also be a chronic inflammatory condition that requires management.

Another possible cause is displacement behavior.  In this scenario dogs could be out in the yard and stop to eat grass as a manifestation of another issue.  Just like the way people may chew on their finger if they are stressed or bored, a dog could do the same with grass.  A dog that is out of shape or achey may stop and eat grass during play as a way to pause play and take a break. It could also be because the play is too simple or boring to them.  These two types of behavioral reasons are obviously quite different so developing an understanding of your pet’s physical state is key.

One last reason we have seen for eating grass is a deficiency in the diet.  A diet low in fiber and plant matter may cause some issues with digestion and dogs may instinctively seek to remedy this on their own.  And although this deficiency may be in fiber or plant matter, that is not the only way a diet can be deficient. Grasses and plants do contain trace minerals and the ground they grow on could have possible beneficial bacteria.  So for any dog that is eating grass it is important to examine their diet and make sure it is as healthy and natural as possible.

At Balance Veterinary Center we help pet parents determine if their dog is eating grass because of a problem, and explore and understand the reasons behind these problems.  Some problems may be simple to resolve (such as parasites) but others can be challenging (such as body aches and chronic inflammatory issues). Fecal tests for parasites, physical examination, dietary discussions, lifestyle exploration, lab work, and even herbal and supplemental medicine are methods we use to help solve these issues.  Our unique approach explores your pet as a whole, includes alternative medical options, and empowers you with the knowledge to understand and direct the best health for your pet!