April 23rd, 2019

Why Do Dogs Eat Grass?

The best thing we can do as dog owners is to always be alert of our dog’s behavior, and take steps to reduce our dog’s chances of getting ill from eating grass.

April 23rd, 2019

Why Do Dogs Eat Grass?

There are many things that our furry friends do that leave dog owners scratching their heads. One of those inconceivable habits is eating grass.

A dog laying on a grass bed, smacking her lips.
Anyone else like getting a little taste of grass?

Whether your pup is wandering about in your lawn, or you’re out for a walk in the local park, you may have noticed your dog chomping away at the grass.

Why do they do it? Perhaps you’ve even seen that after eating grass, your dog goes into a vomiting frenzy. Is eating grass unhealthy or dangerous?

It’s apparent that dog owners are concerned. A Google search for “Why do dogs eat grass” returned 94 million results, with an estimated search traffic of 74,000 times per month. That’s roughly once every 35 seconds.

Moreover, many vets claim that they’re asked this question all day.

This article will explain why dogs eat grass, given all available sources and research I could find. We’ll explain all the potential reasons and determine what you can do to discourage your dog from eating grass.

Pica in Dogs – Eating Non-Food Items

Dogs eating grass falls under the category of pica in dogs. Pica is a condition where your dog ingests non-food objects.

This includes furniture, cardboard, paper, rocks, garbage, metal, plastics, anything really… even their own feces.

You could make the argument that grass is actually an edible food–after all, it’s a staple for other animals like cows. However, since we don’t ever purposefully feed dogs grass, it still qualifies as pica in this case.

Pica is not uncommon in dogs. After all, dogs use their mouths to interact with the world all the time. But it can be a very serious problem if they decide to eat something they aren’t supposed to while out and about.

A dog chewing on a pumpkin stem in her mouth.
Found a pumpkin stem today!

And when that something is grass, we dog owners get especially concerned.

Let’s look closer at this form of pica when it comes to grass eating.

Two Types of Canine Grass Eating

Hill’s distinguishes between two types of grass eating behaviors: grazing and instinctive behavior.

The first type is grazing. This is the same term we use for cows when they feed on grass.

Grazing for dogs is mostly harmless if done in reasonable quantities. The dog usually takes just a few chomps of grass and has no negative symptoms.

The other classification is instinctive behavior, where a dog may eat grass to deliberately induce vomiting. This may be because the dog has ingested something poisonous and wants to get it out of his system.

We’ll discuss later whether or not this form of “self-medication” actually holds true.

For now, let’s get into the reasons for why dogs eat grass and weeds.

Cause #1: Your Dog Is Bored.

Is your dog eating grass frantically despite being fed a full, balanced diet? Perhaps it has to do with boredom more than anything else.

A dog resting on a comfy looking blue bed.
Your dog won't stay drowsy forever.

While some dogs are perfectly content spending the day doing nothing (Yuna is one of them), others need more mental stimulation.

Lying around all day is sure to get boring after a while. Lack of stimulation and/or exercise is a common reason why our dogs start engaging in unwanted behaviors. One of them is grass eating.

You may not be spending enough time playing with your dog. Or, you may not be giving your dog enough exposure to new experiences both in and out of the house. Maybe you’re not exercising your dog enough, period.

Boredom in dogs has many causes. But you will almost certainly the effects, in the form of chewed up furniture, dug-up trash, or a significant increase in grass eating.

The good news is, it’s relatively easy to fix this. Generally spending more time with your dog doing more new, engaging activities, or simply just buying them a couple new toys to gnaw on could keep them from wandering out to the lawn for entertainment.

Cause #2: Your Dog Likes The Taste.

Here’s a fact: your dog likes exploring the world with his mouth. Dogs put things in their mouths all the time.

They do this to feel and taste the object. For puppies, sometimes putting an object in their mouth (and sometimes, swallowing it) is the only way to find out what is edible and what is not. Talk about learning a lesson the hard way!

So if your dog has tried eating grass once, and still chooses to come back for more, it’s not hard to fathom why your dog is eating grass: he probably just likes the taste!

Cause #3: Your Dog Is Making Up For A Nutritional Deficiency

Some sources claim that dogs eat grass to make up for a nutritional deficiency.

There have been studies showing that when given a choice, domestic dogs naturally seek a dietary intake that is high in fat. Similar studies have also shown they naturally seek out foods high in protein.

A closeup of a Labrador's wet snout.
My nose is so powerful I can practically sniff out the fats and proteins!

Does this theory hold true for foods high in fiber too? Well… maybe, and maybe not.

Most sources out there just speculate that grass contains nutrients your dogs may need, without specifically sourcing scientific studies on the matter.

It is definitely possible that your dog is seeking out grass to make up for some fiber, phytonutrients, or potassium that’s missing from their diets.

In that case, I’d recommend just trying to add some other vegetables to your dog’s regular diet, and seeing if the grass eating stops as a result. We’ll talk about good food substitutes in a later section.

But in my opinion, it’s more likely that your dog just enjoys the taste.

Cause #4: Your Dog Might Be Sick

If your dog is desperate to eat grass, it may be because they’re sick.

There are numerous theories out there. One of the most common ones is that dogs eat grass because they’ve got a gassy or upset stomach.

Sometimes, your dog knows when he’s ingested something toxic. He’s got a grumbling tummy and wants to expel the contents, and many vets note that dogs will chomp on large amounts of grass to help them throw up.

After a dog eats raw grass blades, they tickle the throat and stomach lining and trigger vomiting.

This behavior is extremely specific, and really attests to the intelligence of dogs… if it’s true that is! At this time, we do not know for sure whether dogs have the awareness to induce vomiting in this way just by ingesting grass. In fact, some reputable sources consider this explanation a mere myth to be debunked.

Another theory is that your dog is suffering from intestinal worms.

A study from the International Journal of Primatology in 2001 did a study on chimpanzees, where they were observed to swallow leaves to control nodule worm infections. Whether this behavior can be extended to dogs as well is still not clear, but it is a possibility.

Both these theories have been criticized at one point by one source or another. Since there is a lack of scientific research on this topic, we can only currently speculate that dogs self-medicate themselves by ingesting grass when they come across health issues.

A dog licking her lips in front of the Seattle Space Needle.

Speaking of Scientific Studies–Have Any Been Done?

Actually yes–one! From 2008.

There is one study titled “Charactierisation of plant eating in dogs” by Karen Sueda, Benjamin Hart, and Kelly Cliff from the University of California, Davis.

The study first surveyed 47 dog owners whose dogs had daily exposure to plants, reporting that 79% of them had eating grass or other plants.

The study then went online to survey 3340 dog owners, 1571 of which responded with valid answers. Out of those, 68% of dogs had eaten plants on at least a weekly basis; but only 9% were ill, and 22% vomited afterwards.

From this, it is difficult to conclude that dogs eat grass to induce vomiting. Nor is it sensible to conclude that dogs eat grass when they’re sick.

Moreover, this “study” seems more a survey than an actual study with controlled variables.

To conclude, this source simply concludes that plant eating is a normal behavior of domestic dogs.

That is a pretty disappointing conclusion, if you ask me… but well, it’s all we have so far!

A dog with her ears perched, posing in front of cherry blossom trees.
If any new studies come out, I'm all ears!

But My Dog IS Eating Grass And Vomiting. Should I Be Concerned?

If your dog is eating grass and you don’t notice any ill effects, I wouldn’t be too concerned. I would consider adding some cooked veggies to your dog’s diet, which we will discuss in the next section, but you probably don’t need to visit the vet for this alone.

However, if your dog starts vomiting frequently after eating grass, first stop them from doing so, bring them inside, then consult a vet.

Perhaps the vomiting is indicative of something else going on with your dog. Your vet may choose to conduct a fecal float test and blood test to check for a gastrointestinal disease.

Additionally, many lawn care items can contain ingredients that are especially poisonous for dogs. Be careful with any pesticides or products you use to maintain your yards.

Finally, I will note that allowing your dog to develop the habit of ingesting yard plants is generally not good. There are many common garden flowers that are poisonous to dogs as well.

A graphic showing the common flowers your dog should avoid.
See a vet if your dog eats any of these flowers.

So in general, though eating grass itself in reasonable quantities is not cause for alarm, finding ways to curb this behavior is desired.

How To Stop Your Dog From Eating Grass

So what are some ways to try and discourage grass eating? The most straightforward way is to introduce some roughage (food high in fiber content) to your dog’s diet.

There are a few good options here. Sources suggest that since grass is cool, fresh, and textured, good veggie substitutes would be carrots, peeled celery and lettuce.

Steaming these veggies without any seasoning and adding them to your dog’s diet is also just a great health booster.

It may be that your dog continues to eat grass. If your dog has already developed this habit, you need to start supervising your dog while they’re out in the yard, or begin enforcing boundaries.

Some even suggest buying a small tray of grass just for your dog or even starting an indoor herbal garden! The benefit to this is that you control their grass intake and eliminate the possibility of them ingesting any poisonous lawn care chemicals.

Finally, going back to the idea of boredom, maybe they just need more stimulation from you!


A graphic showing the possible reasons your dog is eating grass.
A quick summary of what we covered today.

So why do dogs eat grass? We have given many possibilities in this article, but until there is more research done on the topic, most of these theories are just educated guesses.

The best thing we can do as dog owners is to always be alert of our dog’s behavior, and take steps to reduce our dog’s chances of getting ill from eating grass.

Perhaps the old adage of “going with your gut feeling” applies well here–if you think something is wrong, it probably is. Any abnormal or extreme vomiting should be examined by the vet.

Does your dog eat grass? Tell us about your experiences!

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