Why Do Dogs Eat Grass – The Definitive Answer

Written by: Milica Brzakovic
Every dog owner has seen its dog eating grass, but the question ‘’why’’ is often asked when this type of behavior comes up. There are various explications, but not only one right answer. Let's take a closer look!

The first time you see you dog eating grass you may be confused and maybe even worried.

Is my dog sick? Bored? Hungry? Am I not feeding him properly?

Don’t worry, you’re not alone to ask all these questions!

Most dogs eat grass from time to time, some more often than others. This is completely normal.

However, if this becomes a very frequent habit or if your dog starts eating big amounts of grass even if it has never done it before, this could be something you should look into and pay more attention to.

There are many speculations and explications, but it’s still not sure exactly why dogs have this habit. Here are some of the more common explanations.

Why Is My Dog Eating Grass?

Dogs eating grass are one of those things dogs do that stay a mystery for us. As mentioned, there are many possible reasons that could lead to this behavior. Let’s take a look at all these theories!

1. Intent to Vomit

You will probably see your door by the door, impatiently waiting to get out. As soon as he goes out, he will gulp down a a big amount of grass – no matter what kind of grass. After having eaten the grass, he will start licking his lips, which is a clear sign that vomiting is about to start.

If a meal hasn’t been properly digested and your dog feels a bit sick it’s normal that it wants the feeling to stop. This is why the dog will ingest a big quantity of grass in a short period of time. This amount of grass will irritate the stomach and make the dog vomit, after which he or she will probably feel better.

In this case, the grass eating is for a purgative purpose. Whatever it is inside the stomach that’s causing discomfort, or even pain, the dog wants to get rid of it.

According to some studies, dogs that eat grass fast will probably vomit afterwards, which isn’t the case with dogs that eat slowly. Therefore, the conclusion could be that dogs that eat grass rapidly do it for a purpose – to vomit and feel better.

2. Craving

This behavior is a bit different from the previous one. In this case the dog doesn’t show the need for large amounts of grass and he eats selectively, not indiscriminately like in the previous case.

Believe it or not, some dogs eat grass simply because they like it. They like the taste and will eat it even if they don’t want to throw up. They might like the way grass feels in their mouth or something else.

It’s difficult to determine if your dog is eating grass because he likes it or for some other reason. However, if you notice that he doesn’t eat rapidly and that he’s being a bit choosy about the grass it could very possibly be signs of your dog liking the taste or the feeling.

3. Psychological Condition

This theory is based on the belief that grass eating is a result of psychological problems. Dogs, like people, tend to do strange, but comforting behavior when they’re upset. For some dogs grass eating falls under this category!

Severe anxiety problems can result in compulsive behavior, like this one. If you notice that your dog is unusually anxious when eating grass, this could be an explication why.

4. Natural Instinct

The dog’s ancestor is the wolf who had a ”diet” based on meat, berries and grass. This inharited behavior could be the reason your dog is eating grass.

According to this theory, dogs eat grass because it’s a natural instinct. If you think that dogs are carnivores, you are wrong. They are actually omnivores to a certain degree.

Before they became domesticated, dogs ate whatever they could scavenge. That way, dogs used to eat prey items, meat, organs, bones etc. Quite different from the food we’re giving them today!

Even though dogs don’t have to get their food by themselves anymore, it is believed that they still have a natural scavenging instinct. Wild dogs still eat plants, vegetation and grass, but for domesticated dogs the easiest is to obtain grass and satisfy this inherited instinct.

Most dogs with this instinct don’t understand why they are doing it, but they keep doing it because it’s natural to them.

5. Pica

Pica means eating something that isn’t food, something that isn’t normally edible. When your dog eats things like sand, earth, grass it all fall down under the category of pica.

Pica can be a consequence of various problems, such as issues with pancreas, digestion or metabolism, but it’s usually believed that a dietary imbalance (lack of fibers) is behind this behavior. However, it can be a sign of boredom as well, especially when it comes to puppies and younger dogs.

If this type of behavior continues it would be best to consult your vet who will run different tests in order to discover what’s causing this kind of behavior.

6. Improving Digestion

Some believe that dogs eat grass because they want to improve their own digestion. How can grass do that, you ask yourself?

This is because grass contains fibers, which are necessary in a dog’s diet. Dogs have certain nutritional needs that need to be filled, fibers included.

If your dog’s diet isn’t as rich in fibers as it should be, the dog will look for fibers elsewhere, for example in grass. If the lack of fiber is the case you have to add fibers to your dog’s meals. Fibers can be found in carrots, broccoli and kale.

7. Lack of Attention

This theory is often being overlooked, but could in fact be behind all the grass eating. If the dog isn’t getting enough attention, it will do something forbidden or unwanted in order to gain the owner’s attention.

8. Boredom

A lack of owner engagement can lead to boredom. Boredom can result in all types of unwanted behavior, in this case too much grass eating.

Dogs need regular exercise and interaction. If this need isn’t fulfilled, they will start entertaining themselves, which can explain why your dog suddenly started eating an awful lot of grass.

Is Grass Eating Dangerous?

Having read about the possible theories behind grass eating, you now ask yourself if this is something alarming and something you should worry about. So…is it? Should you let dogs eat grass?

Unlike with some plants that are poisonous for canines, if your dog eats grass from time to time in normal amounts it isn’t something you need to worry about. However, there are some situations where grass eating shouldn’t be allowed.

Good to know: Learn what you can expect if your dog eats arborvitae

When Should Grass Eating Be Prevented?

The most important of these cases is when grass has been treated with chemicals. Certain herbicides and pesticides on lawns can be toxic, in particular if ingested.

In public parks and other public places, companies have the obligation to put around warning signs if the grass contains pesticides or chemicals. Not only is it dangerous because they can swallow it, but they can also lick it off the pads of their feet.

In these situations, where grass is contaminated, dogs should always be kept away from the lawns. Pesticides and herbicides are one of the most common causes of pet poisoning.

Last but not least, keep in mind that some plants in the garden can also be toxic and lead to problems if they get swallowed together with grass, so make sure to inform yourself.

But what if the grass isn’t treated with chemicals, should you stop your dog from eating grass anyway?

If your dog is eating grass, you have to ask yourself the following questions:

– Is this behavior new?
– Is it frequent and is it like a routine, at the same time every day?
– Is your dog vomiting after grass eating?
– Are there some other symptoms you notice or is your dog not the same as usual?

If your answer to these questions is yes, it’s possible that something has changed and a visit to the veterinarian could be a good idea.

How Do I Stop My Dog From Eating Grass?

In order to stop your dog from eating grass, you first have to determine what’s causing your dog to do it. Easier said than done!

If you think the reason why your dog is eating grass is boredom, you should make sure he’s getting enough interaction and exercise, both mental and physical. Create interesting activities, such as tossing a Frisbee or another active game. Same goes for attention.

If the reason is nutritional deficiency, try switching to a better dog food or add the substances that are missing, most importantly high-fiber substances, such as broccoli, kale and cauliflower. Keep in mind that every diet change should be done slowly and in small steps, even good changes.

Another method is to add raw or lightly cooked vegetables and that way increase fiber content.

However, it’s important to inform yourself beforehand on bad food for dogs so you know what’s safe to give them.

If your dog is eating grass out of a natural instinct, it’s possible to train this out of your dog, but if it’s not causing any medical problems there is no reason to do it. It can only lead to unnecessary stress and the dog will probably feel like someone is preventing them from behaving naturally.

If your dog is anxious and he manifests it through grass eating, it’s important to consult a vet and find the right solution. There are various methods, such as desensitization therapy, herbal remedies, increased exercise, prescribed medications etc. so it’s all about finding the right one.

Determining The Cause Behind Grass Eating

It can be very difficult to identify why your dog is eating grass, but it’s vital if you think that something is wrong and should be changed.

The first step is to visit a vet for tests, such as blood drawl, fecal and urine testing in order to check for potential problems. It’s important that you can report about your dog’s behavior related to grass eating so that the vet can easier figure out the cause.

Most often, no signs of sickness are found which indicate other causes, such as lack of fibers. Suggested methods usually include diet changes, simple training methods with for example treats or positive reinforcement, or allowing the grass eating as long as it’s monitored.


Grass eating is something most dogs do at some point. Even though there isn’t only one right answer that can explain why, it’s important to know that it’s normal and usually harmless.

Determining the cause behind the grass eating can be difficult, but we hope that we made it easier for you now that you know what different causes can be behind it.

As long as you keep your dog off lawns with pesticides and chemicals and you monitor for other signs of problems, occasional grass eating is completely fine and not dangerous!