Why do dogs eat grass?

ask a vet, online vet, why do dogs eat grass

It’s a question I’ve heard more times than I can remember, and yes, as a dog owner, I too have seen my own dogs (and cats) go outside for a munch of the green stuff, chow down, and often times throw it right back out.

Dogs too often will seek out a natural remedy for their GI ailments, be it if their tummy is upset or if they are feeling a bit bloated and gassy. Typically they will nibble just a bit, but some dogs will graze more.

So why do dogs eat grass and then throw it up?

When they eat the blades of grass, it is believed the tiny “hairs” on the blade tickle the esophagus and stomach as they go do. This then often causes the dog to vomit, which may be just what the doctor ordered if something they ate is upsetting their tummy.

Many household and landscaping plants are poisonous to dogs, and dogs are no better botanists than their people, so make sure they don’t have access to the dangerous herbage.

Typically, dogs will chew and graze more when they are feeling well. The more they chew the grass, the more the blade becomes saturated with saliva, and in becoming so, it is less “tickly” as they swallow. These dogs may just be craving some roughage in their diet, or may find the texture appealing.

Alternatively, the quicker they gulp it down, the more likely they are to throw it right back up.

So, why do dogs find grass appealing?

Dogs, unlike cats, are not carnivores. Their ancestors would often eat their prey entirely, including the stomach contents of grass and vegetable eating prey. Dogs in the wild have also been known to eat vegetables and berries. Dogs have nutritional requirements that are not met by just meat.

When you let your dog loose in the back yard, it makes sense for him or her to eat whatever is accessible, and that is usually grass. Most dogs aren’t the pickiest of eaters, and today just as history shows us, dogs devour anything and everything to meet their dietary requirements. Ever given your leftovers that you were bored with to your dog? Chances are, unless you are the proud pet parent of a tea-cup chihuahua, Fido was happy to clean your Tupperware.

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The consensus on safety

Whatever the reason for chowing down on some green may be, there really is no danger in letting your dog eat grass.  You can even grow them some safe grass free of chemicals indoors to munch on:

Cats and dogs instinctively chew & eat grass to obtain vitamins, minerals and live enzymes provided ...

But not much in veterinary medicine is without a catch…

  • There is no danger as long as your grass hasn’t been treated with chemicals.
  • Many parasites have eggs in the yard, so eating grass is a common way for your dog to contract intestinal parasites.  If your dog is kept on heartworm meds year round, this shouldn’t be a problem, as heartworm meds protect against the most common intestinal parasites.
Also, if your dog was never prone to eating grass, suddenly becomes starts eating lots of it and vomiting, it may be a sign of a serious illness they are trying to self-treat. In this case you should ask a vet.

If your dog is a frequent grass consumer, it could be a sign they are missing some fresh produce in their diet. While raw veggies are great, a number of dogs won’t eat them.  Cooking vegetables and adding them to their diet may decrease the amount of time they spend grazing the green.

So let’s take a poll and find out how common this is among  dogs.  Does your dog eat grass from time to time?

Dr. Laci


Dr. Laci Nash Schaible, DVM

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February 21, 2011 at 18:13

Both Jasmine and J.D. eat grass, but they are very particular about which one. They eat that one when it’s available. That is interesting on its own. They usually don’t throw up after eating it, though Jasmine is more likely to seek it when her stomach is upset.

Our vet believes that grass does mechanical damage to the stomach though ..?

February 22, 2011 at 11:26

Hi Jana,

Maybe that particular type has a preferable flavor or texture? I haven’t heard anything about mechanical damamge though. Interesting.

Conni Ersland
February 21, 2011 at 20:49

Thanks Dr. Laci! I will try adding some veggies to their diet and see if the grass eating subsides a little…

February 23, 2011 at 13:26

You are very welcome Conni! Thank YOU for the great question. The veggies certainly can’t hurt and are always a healthy addition to any pooch’s diet provided they are healthy and don’t have diseases that would restrict or alter their dietary intake–like kidney failure or diabetes.

Hope it helped shed some light, and thanks for commenting!

February 22, 2011 at 15:18

Our dogs (both permanent residents and fosters) seem to be most interested in eating grass for sheer enjoyment in the spring when it is new. Other times of the year they don’t eat much grass unless they need to heave their cookies.

Many of them also really like to chow down on the wild mint that grows in our yard.

February 23, 2011 at 13:27


That is really interesting and make perfect sense regarding the spring grass cravings / novelty of it. HAHA, we look forward to sunshine and flowers and they are excited about different snacks. Thanks for commenting!

Linda Oliphant
February 22, 2011 at 15:23

My dogs both eat grass. One not very often, so when I would see him eating grass I would give him some canned green beans on his food. I just thought he may like some veggies if he is eating grass. The other dog eats grass more often and vomits often also. He is a grazer, so I keep a close eye on him to make sure he isn’t sick for too long.

February 23, 2011 at 13:29

Linda, It sounds like you are on top of it! Funny how they have their preferences just like we do. Thanks for reading and commenting!

March 3, 2011 at 22:41

My dog is eating A LOT LESS grass since he started a hydrolyzed protein diet.
He loved (and still eats some) wild/weedy early spring grass, and has a particular favorite. He does not eat the (chemical free) lawn. He once vomited a clump of grass that was the size and shape of a small gopher. I think he only vomited after eating grass one other time in his many years of grazing. Generally, the grass moves through his system w/out being digested.

Dr. Jed Schaible
March 4, 2011 at 11:35

KD, Sounds like there may have been a nutritional component. Glad it sounds like you have found a diet that is better meeting his nutritional needs and satisfying his taste buds! Gopher sized–geez!

Thanks for commenting!

Rachel G.
May 26, 2012 at 22:17

My cat looooooooooves grass. I can go outside and cut a few tiny pieces for him to eat, walk into my room and he instantly knows that I have grass (I hide it in my hand). He loves it more than catnip. The only problem is, if I let him eat it, he starts to throw up (normal) but then starts to go limp and sort of acts like he is going pass out. It scares me so I don’t let him eat grass anymore. This is awful because he cries and cries and cries to go outside and eat grass. Once in awhile I do cut tiny pieces and give it to him. if they’re tiny pieces he seems all right.

Barry Hyde
June 7, 2012 at 21:46

I feed my German Shepard wheatgrass once a week and he loves it and this keeps him from eating grass from the yard and it really seems to help his digestive system. He has never been sick since we started feeding him whetgrass!

August 2, 2012 at 20:58

i have a 2 year old king shepard boxer dingo pit mix and he grazes like a cow eating grass everytime he goes out side but he never throws up so i read your article and i will start giving him cooked vegestables thanks Kim

August 12, 2012 at 09:55

I don’t like that picture. Dogs should never have corn on or off the cob. Too much can be toxic and even a little can cause gut problems.