Why Does My Dog Eat Grass?

Yorkie dog in the grass

Our dogs are certainly very funny creatures. We love their antics and all the quirky things that make them unique and special. But sometimes we notice a behavior that is quite strange to us. We see them munching on a blade (or whole pile) of grass.

Naturally, we wonder why they would so willingly go for a plant-based snack, being such carnivores as they are. We wonder if they’re pretending to be a horse, or maybe copying a cat they may have seen doing this.

Such an action is quite common in dogs, and nothing to worry about right off the bat. Though, there are several reasons why this behavior should be discouraged.

Let’s take a look at assumptions we make when our dogs eat grass, followed by some evidence-based theories as to the causes of this behavior. 

Common Belief: Canine Purging

Chances are if you see your dog eating grass the first thing you’ll assume is that they’re doing a sort of canine purge to clean their stomach from something that’s making them feel unwell.  

It’s a common belief that dogs eat grass to detox their stomach. Especially if the grass-eating is followed by vomit. However, it has not been proven that dogs are sufficiently self-aware to do an auto-inflicted medicinal practice. 

The truth behind this myth probably has to do with their instinct: wolves and other wild animals like foxes and coyotes also eat grass. 

If you believe your dog may have an upset stomach watch out for the following symptoms.

  • Nausea (Licking lips or licking the air)
  • Vomiting
  • Diarrhea
  • Lethargy
  • Gulping

If your dog displays any of these symptoms, analyze the severity and act accordingly. If the symptoms are mild, have your dog skip a meal. If they’re severe, contact your veterinarian. 

Why Do Dogs Eat Grass: Research-Based Information

Nutritional Deficiency

There has been sufficient evidence that links grass-eating behavior to a nutritional deficiency. There’s a case of an 11-year miniature poodle who had a long history of grass eating, followed by vomiting, that is often referenced to this point. After being provided with a high-fiber diet, the dog’s grass-eating behavior stopped. 

If you believe your dog has a nutritional deficiency, make sure they’re on a diet that’s appropriate for their breed and age. Check with your veterinarian to be on the safe side. 


“Pica” is a medical condition in which dogs feel the urge to chew on non-edible substances. The causes could be behavioral or medical. Dogs may chew on non-edible substances because they’re stressed out or have separation anxiety. 

They could also be doing this because they’re anemic or unable to absorb certain nutrients. This sub-type of Pica is called geophagia, and it involves behavior such as eating dirt. If you notice your dog has this behavior check with your veterinarian to ensure they’re getting and absorbing adequate nutrients.

Normal Dog Behavior: Boredom, Curiosity, and Attention Seeking

Some more ordinary reasons why dogs eat grass could simply be boredom, curiosity, or plain taste. Grass eating could merely be a quirky thing your dog enjoys. Or maybe your dog is a high-energy breed, and their energy requirements aren’t being fully met. They could be eating grass as a coping mechanism.

Another prominent reason for this behavior could be attention seeking. This would depend on the dog’s intelligence, which is quite high for most breeds. If your dog notices that every time they munch on grass they get attention from you, they’re likely to repeat this behavior.

Is Grass Eating a Threat to My Dog?

We’ve covered the reasons and circumstances that can cause a dog to eat grass. 

But, is this behavior a threat to them? The answer is that in and of itself, eating grass is not harmful to your dog. Dogs can’t fully digest grass, it will simply go through their digestive system. 

The drawback is that, depending on the grass, there could be some substances on it that can be harmful to your dog. These are pesticides, pathogens, and toxins. 

Pesticides are of common use on grass and plants, so if your dog eats grass from a field that you’re not familiar with, they could be ingesting an uncertain amount of pesticide. This can be more or less harmful to your dog, but either way, it poses a threat. 

As for pathogens: if the grass has come into contact with the feces or urine of an infected animal, it could have bacteria that may be harmful to your dog and could produce parasites or a serious illness such as leptospirosis.

In addition to this, some plants may be toxic (such as Daffodils), and your dog will probably not distinguish it from grass. Hence, parts of unwanted leaves may make it to your dog’s mouth, potentially causing an undesired intoxication. 

How Can I Keep My Dog From Eating Grass, and Should I? 

Unless your dog is eating grass from a whole-food source, absolutely non-GMO, organic, and quality inspected, they should abstain from it. All kidding aside: To stay on the safe side, it’s best for your dog to only eat grass if it is clean and safe. 

Here are some tips to discourage grass-eating behavior:

  • Keep your dog on a leash when going to grassy areas.
  • Time your dog’s walks so they occur after a meal, that way they go on a full stomach.
  • When you notice your dog eating grass, calmly interrupt them and suggest they do something else. When the alternative behavior is performed, give your dog a treat or positive reinforcement. 
  • Avoid scolding them when they eat grass.
  • Some dog muzzles can help keep your dog from eating grass and other objects while on their walks if necessary.


Dogs are complex and highly intelligent animals. While there’s no certain answer as to why they do things like eating grass, the best you can do is to pay attention to their behavior and address it. Get to know your dog’s habits, rule out medical conditions by taking them to the vet, and investigate if they’re bored, anxious, or just quirky. 

  1. This was very informative.

    We are a relatively new pup owner, and though we have had 4 previously rescued dogs, they were all pure bread pugs. Our current pup was adopted through a rescue for all breeds and she’s a mix with very different traits and needs from a pug.

    She is almost 9 months old and I am coming to terms that her incredibly high energy is why she feels the need to eat grass (and pretty much anything she can get into her mouth faster than we can grab). We’ve increased her activity levels, but being her age and her suspected breeds, we may need to add some additional activities to her schedule. But this article gave us some good things to watch for as well, so it’s much appreciated, Thank you!

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