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Why Do Some Dogs Eat Grass?


As an owner of 3 dogs all ranging in different ages, my dog’s health is a top priority.

I spend a lot of money on providing them with nutritious high-fiber dog food filled with everything that they need to stay in good tip-top shape because I want them to be with me for a very long time. 

That’s why it drives me insane when sometimes I catch them with mouthfuls of grass from our yard. 

Thankfully, none of them vomit afterward which leads me to believe that they like the texture of grass or they just want to think that they’re ancient wild dogs. 

My previous dog Leroy, who had inflammatory bowel disease, used to eat large clumps of freshly cut grass and again, he never vomited afterward but I learned that it was a sign that he was about to have a flare-up.

young dog eating grass in yard

Why Do Dogs Eat Grass?

Ah, the age-old question that all dog owners have that doesn’t have a simple explanation!

Truth be told, it seems that there’s no short answer to this because dogs can’t tell us why they’re eating grass, we as pet parents just have to watch and observe and talk with our veterinarian if we have concerns.

But let’s dive in just a little bit deeper about our dog’s grass-eating habit.

Years ago and even now, some people and veterinarians believe that when a dog is eating grass it’s a sign of a vitamin deficiency. 

does eating grass make a dog sick

There is something lacking in their diet such as not getting enough fiber, so they seek out grass to help them pass gas, stool and to assist other bodily functions. 

However, a study performed by the UC Davis School of Veterinary Medicine, found that although grass eating was a common behavior seen in dogs, no clinical connection was identified. 

Some dogs were found to vomit after ingesting too much grass but they were found not to have any obvious signs of illness and these dogs did not have access to eating grass regularly. 

Further investigation revealed that dogs without regular access to grass were more likely to vomit after ingesting it.

It is now believed that grass can act as a stomach irritant in dogs that are unaccustomed to it.

It is possible some dogs may learn to associate grass-eating with vomiting and seek it out when they are feeling ill.

However, this study revealed that grass ingestion does not appear to be a form of self-medication in dogs with a clinical illness.

Two Main Types Of Grass Eating

The common theories of why a dog eats grass is normally for 2 reasons:

  • grazing
  • instinctive behavior


The most common reason that dogs eat grass is that they can. 

It’s usually just a dog going outside in your yard, walking around and they decide to take a taste of grass. 

A dog that is in good health and just eats small amounts of grass can be normal dog behavior. 

For some dogs, eating grass can be a sign of an upset stomach or even conditions such as inflammatory bowel disease and they are looking to relieve that discomfort by eating grass. 


dog eating grass field

Younger dogs will often eat grass out of curiosity or it’s a sign of boredom.

For some dogs, it can be a sign of separation anxiety and also a sign that a dog is lacking mental stimulation.

Instinctive Behavior

The other main reason for dogs to eat grass is more of instinctive behavior. 

As mentioned above, this is sometimes thought to be a dog’s instinct to try and make themselves vomit. 

They could do this because they ate something that doesn’t agree with them and they have an upset stomach and their instinct is to try to vomit so that they feel better. 

Dogs that are feeling sick will normally seek out grass quickly and swallow it without really taking the time to chew it.  

Some people say that the long grass tickles their throat and in turn, makes them vomit. 

It makes perfect sense if you think about it!

Not All Grass Is the Same

It is important to keep in mind that not all grass is safe or healthy for dogs to eat.

It’s not so much that your type of grass is harmful to dogs but what’s hidden in the grass such as toxic mushrooms which can accidentally be ingested when a dog is grazing.  

Grass that has been treated with toxic chemicals during the summer months such as fertilizers, grass seed or a weed control product should also not be consumed by any pets. (If you have a yard service that takes care of your lawn on regular basis, it’s always a good idea to ask them what type of yard sprays they use and if it’s safe for dogs)

can dogs eat grass

Some lawn grass can also be home to parasites such as hookworms and roundworms that come from the feces of other dogs.

So if dog owners are going to let your dog eat grass, make sure it’s safe grass and keep your dog away from tall grass and grass-type weeds in public areas.

How To Make A Dog Stop Eating Grass

If your dog’s grass-eating habit is driving you insane and you’re worried about their health, the best way to stop them is to not leave them unattended on your own lawn, which I know sounds a lot easier than it is. 

But you need to break the habit and in order to do that, you need to be there to correct them. 

If you think your dog might be bored and that’s why they’ve turned to chowing down grass and dirt, offer them some more mental stimulation. 

If you suspect that your dog might have a nutritional deficiency, reach out to your vet or schedule a vet visit and ask for suggestions on a commercial diet, cooked diet or raw diet that might be better suited for their needs. 

When To Be Concerned

A healthy dog that is eating mouthfuls of grass or a dog that shows a sudden increase in eating grass should be monitored.

Dogs that are vomiting often or have other medical issues should be seen by a veterinarian. 

Puppies that are vomiting, lethargic, eating grass, experiencing weight loss, and have diarrhea should seek veterinary advice.

A few blades of grass normally won’t cause issues but if a dog is eating excessive amounts of grass,  especially piles of freshly cut, wet grass it can get lodged in the small intestines and cause an intestinal blockage. 

Should You Let Your Dog Eat Grass?

This post is for informational purposes only, if you’re concerned about your dog’s health or their grass-eating habits you should always speak with your veterinarian to rule out any medical conditions. 

Some dogs just really like to graze on grass and it’s perfectly fine for them. 

I would caution that if your dog likes to eat freshly cut grass that you don’t allow them to eat clumps of it which can cause an intestinal blockage. 

I always try to pick up the big clumps of grass left behind by the lawnmower, especially if they are wet. 

So is your dog a grass eater? A grazer? Do they ever vomit?

Contary to popular belief, when dogs eat grass it doesn't always mean that they are feeling sick. Many dogs will eat grass because they like the taste of it.



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Jan K

Monday 2nd of July 2018

This was so interesting, but University of CA seems to be the ones that got it right. We have definitely had dogs that sought out grass when they don't feel well, and if they did, it would make them vomit. But they always had access to it. However, Luke eats grass all the time, and very rarely vomits. It sometimes even seems like an obsessive behavior with him, or he just simply likes it. Now, you need to figure out why cats do it. Ours definitely seems to love it, but she never keeps it down!

My Golden Life

Sunday 10th of June 2018

Shadow doesnt usually eat grass unless she's hungry. And I can't remember the last time she vomited.

Ducky, OTH, will eat anything she can find in the yard EXCEPT grass. She will eat dirt, dead leaves, pieces of twigs, pieces of acorn shells, and just recently - are you ready? - birdseed!! Normally, though, it's only when she's eaten her breakfast or dinner too quickly and can't get it to go down properly so she gets obsessive about eating anything to make it all come back up. The obsessiveness was quite frequent when she was having the IBS episodes; but now that we have that mostly under control, it's only an occasional thing. And, luckily, most times I catch it before it gets too bad. Our vet suggested trying CatLax for her at those times. I've only known it to not work twice in the last year.

Dan Zurcher

Friday 8th of June 2018

Our last 2 Newfy's have been grass eaters. I think the younger one does just because the older one does. He eats the long grasses one blade at a time every day, never vomits. Neither one does. We had a Great Pyrenees a few years ago who would eat grass and vomit pretty regularly. The Newfs never do....

Thursday 7th of June 2018

Years ago vets used to say that dogs induce vomiting by eating long grass to tickle the back of the throat. I find it interesting that my dogs always eat from a very small patch of grass in the garden, I never see them eating from other areas. I think mine just like a little salad now and again!


Thursday 7th of June 2018

I'm pretty sure that's what our old vet use to say too. Sherman doesn't do it everyday but if he sees a long blade of a grass he goes for it. It's so funny because he's so gentle about it!

Tails Around the Ranch

Wednesday 6th of June 2018

Some dogs (like Old English Sheepdogs) are genetically programmed to eat grass. When they worked the Highlands watching herds of sheep, it was the majority of their food. Thanks for sharing info on this interesting topic. It's a lot like the what came first, the chicken or the egg conundrum. ?


Thursday 7th of June 2018

That's pretty cool to know! Thanks for sharing!

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