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Call us: 708-383-3606 | Get Directions | After Hour Emergencies: 773-281-7110

Why Do Dogs Eat Grass?


Grass certainly doesn’t seem like a delicacy.  In fact, it tastes downright terrible. (Who hasn’t tried grass sometime when they were a kid?).  So why do dogs tear into it with such passion?  Not much is known about why dogs eat grass, but studies indicate that it is a common and normal behavior of most domestic dogs.

It is estimated that 79% of dogs engage in plant eating behaviors, with grass being the most frequently eaten plant.  Of those grass eating dogs, 86% eat grass on a daily or weekly basis.  Grass eating is observed in both wolves and dogs, suggesting that the behavior was preserved through domestication and is innate (Price et al. 2009).

What drives grass eating?

No one knows for sure why dogs eat grass.  One study showed that grass eating is influenced by satiety and time of day.  Dogs are more likely to eat grass if they are hungry (Price et al. 2007).  So, perhaps dogs are just eating grass because it is a tasty snack?

There are many theories circulating that grass eating in dogs is tied to digestion.  It has been postulated that dogs eat grass to cause themselves to vomit when they are feeling unwell.  This may be advantageous if they had eaten something that was causing gastrointestinal distress.  This type of grass eating is thought to be different from “normal” grass eating in dogs.  While healthy dogs tend to contentedly graze on grass, dogs with associated gastrointestinal ailments are speculated to gulp down grass quickly and without chewing.  The theory is that this will tickle the throat and cause vomiting, thus voiding the stomach of contents that may be causing discomfort (Hill’s Pet Care Center).

While there is not a lot of current research to support a theory of gastrointestinal distress associated  grass eating, it is certainly still plausible.  Of all grass eating dogs, 9% were reported to frequently appear ill before eating plants and 22% were reported to frequently vomit afterward (Cliff et al. 2008).

When should I be worried about grass eating?

While most grass eating in dogs is benign, there are some instances of grass eating that raise concern.

If your dog’s grass eating has increased in frequency or is associated with signs of vomiting, diarrhea or inappetence, please contact us to set up an appointment.  Please beware that some herbicides or pesticides found on grass may be toxic.  Additionally, if your dog eats other types of plants, there is a risk that those plants may be toxic.  If you do not know if a plant or herbicide/pesticide is toxic, please contact us or call ASPCA Animal Poison Control for more information.

It is our pleasure to serve you and your pets. Please do not hesitate to call our offices (708-383-3606) if you have any questions or concerns. Thank you for allowing us to be a part of your veterinary healthcare team.


Contact Us

Carlson Animal Hospital


414 Lake St. Oak Park, IL 60302

Clinic Hours

Monday-Tuesday: 8 AM-12 PM, 1-6 PM Wednesday: 8 AM-12 PM, 1 PM-6 PM Thursday-Friday: 8 AM-12 PM, 1-5 PM Saturday: 8 AM-1 PM Sunday: Closed