Why Do Dogs Eat Grass – 9 Reasons Backed By Science

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Why Do Dogs Eat Grass

Here is a jump-to-table of contents. In this article I will discuss:

1. Why Do Dogs Eat Grass
2. How To Stop My Dog From Eating Grass
3. Is My Dog Eating Grass Harmful Or Dangerous
4. Why Do Dogs Eat Grass And Vomit
5. Why Is My Dog Eating Grass All Of A Sudden
6. What Types Of Grass Are Dangerous For A Dog?
7. Unresearched Reasons Why Dogs Eat Grass
8. Dog Parent Takeaways

Why Do Dogs Eat Grass?

It’s common to see a dog eating grass. Dogs eating grass straddles the line between dog behavior, dog nutrition and dog biology. Luckily for you, I am a Certified Dog Behaviorist and Dog Nutritionist.

That’s relevant because Certified Dog Behaviorists and Nutritionists specialize in both reasons why a dog might eat grass. Your dog eats grass typically due to behavioral and/or nutritional factors. So let’s dig in.

TL;DR:

• Dogs eat grass because exploring the world through their mouth is normal behavior and part of the canine ethogram (and healthy as long as the grass is organic.)
• It’s part of a dog’s genetics. Dogs are omnivores that scavenge, forage, and love carrion smells/tastes such as vile, pungent odors and stuff to play with and eat. Dogs eat lots of things with zero nutritional value for fun or because it seems interesting to them (like eating poop.)
• The most effective way to get your dog to stop eating grass is management. However, there are many other methods and factors to consider that may help with grass-eating dogs such as dog training, behavior modification, enrichment, exercise, and nutrition.

In a written survey of 47 pet parents, 79% of healthy dogs ate grass.

That includes grass and/or other plants.

Further, 68% of dogs ate grass regularly (daily or weekly) while other dogs ate grass once a month.

For example, while at my dog boot camp in Los Angeles, many dogs munch on grass, sticks, bark, leaves and other organic matter.

Eating grass is very common.

Here are 9 reasons dog eat grass backed by science and experience.

Dogs Eat Grass Because:

1. It’s FUN! Dogs explore the world through their mouths (and all other senses)
2. It’s a displacement behavior (anxiety-reducing behavior, similar to how a person may tap their foot, twirl their hair or bite their nails)
3. A dog may have nutritional deficiencies
4. It’s an attention-seeking behavior. If a dog is not getting enough attention (or dog training they will quickly figure out how to get your attention. If your dog needs more social interaction and attention from you and eating grass gets your attention (even if you yell at your dog to stop! – which is attention) they will continue to eat grass to get attention.
5. Dogs will enrich and entertain themselves. If a dog is under-enriched and trained, (AKA bored) they will employ themselves and we won’t always like what jobs they decide are fun.
6. Grass tastes good
7. Grass feels good on a dog’s tongue, mouth, teeth and gums (just like people chew twigs, toothpicks, gum, etc.)
8. Hunger – some research papers have discussed the time of day and how hungry your dog is as a reason for grass-eating. It stands to reason that satiety (the hungrier you are) the more desperate you become and the more food sources you will eat for survival. However even though true, since we are not talking about starving dogs, pack animals or free-roaming dogs or general canids, this is likely off the table as a reason for grass-eating dogs.
9. Fiber – Dogs need fiber and in this one research paper, scientists found one dog, an altered male poodle, where his long-time grass-eating habits disappeared when the dog’s commercial food was changed for a higher fiber food.

 

How To Stop My Dog From Eating Grass

Most importantly how to stop your dog from eating grass is just like all other behaviors, through dog training and management.

However, it will benefit you to get into the habit of asking what behaviors you want your dog to do instead of asking how to STOP a dog from eating grass.

What you would like your dog to do instead? Then practice that often with dog training. Which is what conditioning and learning are all about.

Here are some management and dog training techniques to practice so your dog stops eating grass and instead encourages them to pay attention to you and do other preferred behaviors instead.

• Dog training – Teach your dog any of the following dog behaviors that are incompatible with eating things off the ground such as grass. Teach your dog a strong recall, to look at you, heel next to you as you walk/jog/run, leave it, drop it, stand, etc.
• Behavior Modification through exposure therapies such as differential reinforcement of incompatible/alternative behavior (DRA/DRI) etc. and D/CC
• Have your dog wear a head harness to give you extra control over your dog’s mouth and head
• Condition your dog to love wearing a muzzle. While grass, food and water should be able to be accessed through ALL muzzles, it should help slow down a dog’s grass-eating behavior or give you time to get your dog’s attention when you see them going for grass.
• Management – All dog training requires an environment set up for you and your dog’s success. Keep your dog leashed. Don’t allow your dog outside off-leash or roaming around in your backyard unattended. Pay attention to your dog. Make sure you are feeding your dog complete and balanced high-quality dog food and food items that are healthy and ones that he loves. Here’s a list of dangerous dog foods to stay away from

 

Is My Dog Eating Grass Harmful Or Dangerous

Yes and no. As mentioned there are a number of reasons why dogs eat grass and equally as many reasons to not want your dog to graze on grass.

The most dangerous part of a dog eating grass is the chemicals used to treat lawns, yards and grass fields. Dangerous chemicals on grass can kill your dog.

Don’t let your dog eat grass on any lawn that “looks perfect” or is chemically treated.

The same reason people eat organic fruits and vegetables is the same reason you want to stop your dog from eating grass that has been chemically treated (unfortunately that is most grass you see in the Pacific Palisades, Beverly Hills, or anywhere in Los Angeles or your neighborhood)

Grass Eating Is Not:

• Dangerous for your dog. Your dog eats grass for many reasons, and it is not dangerous as long as the grass isn’t chemically treated.
• Necessarily Pica – Pica is eating non-edible foods typically with insignificant or zero nutritional value. While grass is not complete and balanced it has some nutritional value as a plant and hence what a dog absorbs in the gut from digesting grass is not moot. Pica is also typically associated with eating dangerous non-food items. Eating organic grass is not dangerous.
• Caused by atavistic qualities – Eating grass is not that much of an atavistic behavior. While wolves do eat grass and plants it is not a large part of their diet or behavior.
• Because they are pack animals – Dogs are not pack animals, alpha or wolves
• Because it’s a wild dog. What is a wild dog? Let’s assume wild canids include wolves, jackals, foxes, and coyotes. Of which, dogs Canis lupus familiaris are none. Also, dogs in the wild are very rare and non-existent in the United States let alone in Los Angeles California.

Inherited from a domesticated dog’s ancestors are scavenging and foraging behaviors that contribute to a dog’s opportunistic eating habits.

Because domesticated dogs are not wild dogs then any argument about domesticated dogs doesn’t include wild dogs (or wolves).

To elaborate on the argument comparing domesticated dogs to wild dogs, in actuality community dogs and feral dogs are the closest you will get to “wild” dogs in the United States and most other countries.

Domesticated dogs are scavengers and foragers and not hunters. Hunting (killing prey to survive) has largely been bred out of dogs over the decades through domestication.

Dogs are opportunistic and if they are able to and inclined to hunt other animals (most aren’t) they will usually eat a dead animal not successfully kill a live one.

Yes, a dog might kill a squirrel, rat or vermin on occasion but it’s not a sustainable food source for a domesticated dog. Dogs were selectively bred for thousands of years for domestication. AKA to be dependant upon and to require people to survive.

 

Why Do Dogs Eat Grass And Vomit

As a vegan, I am happy to say that dogs are omnivores, scavengers and foragers (even though taxonomically classified otherwise) They thrive on a balanced and complete diet whether vegan, plant-based or with meat and vegetables.

Yes, dogs can thrive on plant-based diets (balanced and complete) and explore the world through their mouths.

Dogs like to eat non-edible/nutritional items all the time (toys,  poop, sticks, shoes, etc.)

From the same Internet survey of pet parents mentioned earlier, a smaller 22% of the dogs ate grass and vomited after ingestion.

Why dogs eat grass and throw up is likely a cause-and-effect scenario. Either the dog was already ill, ate too much or the type of grass and/or chemicals or bacteria on the grass in the dog park caused vomiting.

However, there is no evidence that shows that dogs eat grass to induce vomiting. But rather, it’s a simple factor of they ate bad “food” (grass).

A dog will eat grass for many reasons, but if the grass is unhealthy or disagrees with their stomach a dog may throw up. Just like when we eat food and occasionally get food poisoning we vomit. But we don’t eat the food to cause vomiting.

Most of the grass a dog eats passes through the dog’s intestinal tract digested. You can see this by Fecal Scoring Chart after your dog eats grass. While some blades of grass may exist (like corn in a human’s poop, yuk) all of the grass contents are not visible and or come out whole. This is not only due to the masticating effect of chewing the grass but also to a dog’s gastrointestinal tract digesting the grass and utilizing some of its nutrients.

Dogs have the ability to digest and thrive on carbohydrates.

The answers to the questions “Is it OK for dogs to eat grass?” and” Should I let my dog eat grass?” is yes.

It is OK and normal for your dog to eat grass.

 

Why Is My Dog Eating Grass All Of A Sudden

In this scenario, if my dog all of a sudden starts to eat grass, take note of the setting events, antecedents, your dog’s overall health, enrichment, training and all of the other factors mentioned above about why dogs eat grass.

It’s likely something has changed in the dog’s diet, environment, and or routine that is either causing boredom, stress, interest, lack of training, enrichment,  etc.

 

What Types Of Grass Are Dangerous For A Dog?

Grass species are all different. For perspective, there are around 12,000 different types of grass in the botanical family Poaceae.

Yes, 12,000!!

They are like all plants, specific to some environments based on weather, elevation, climate, etc. Whether you live in Los Angles, the desert, by the beach, or mountains your environment has certain types of grass.

Some dogs prefer one type of grass over others. (just like dog poop. Gross I know!)

But fresh grass (also like poop) might be more desirable than long, mature grass. Green grass over browner grass, etc.

If your dog is eating a healthy balanced and complete diet and not throwing up after eating grass there is nothing to worry about and your dog can safely eat grass.

If your dog is eating a healthy balanced and complete diet and vomiting either change the grass your dog has access to and/or change your dog’s food and experiment with other foods that have different fiber, vitamins and nutritional content.

It’s also much healthier for a dog’s gut to have a variety of food sources (protein, carbs, vitamins, minerals and nutrients) in their diet and not the same food most of their lives.

 

Unresearched Reasons Why Dogs Eat Grass

After studying dogs for 30 years and spending most of my career as an animal behaviorist and dog trainer, there’s still a lot we don’t know or understand about dogs.

Conjecture and anecdotal reasons you might read in the internet comment sections are that eating grass causes a dog to vomit. While this might be correlated it does not prove causation or intention.

A dog who feels sick or has worms is not likely to eat grass to induce vomiting. Dogs don’t eat grass as an emetic behavior.  Dogs don’t eat grass to vomit.

In a study where a gastrointestinal disturbance was induced in dogs to cause diarrhea, it showed that dogs with mild diarrhea did not seek out grass-eating. Nor did they vomit after eating grass.

These dogs did not eat grass in order to throw up or elevate gastrointestinal illness.

 

Dog Parent Takeaways

Dogs run, drool, roll around in the dirt and eat stuff we don’t want them to. That’s part of being a dog and typically not dangerous or harmful behaviors.

Teach your dog compassionately what you want them to do instead of any unwanted behavior.

If you’re having trouble with your dog’s behavior and want Certified Dog Behaviorist, Trainer and Nutritionist Russell Hartstein to work with you and your dog, get started with our Dog Boot Camp in Los Angeles CA, or hop on a Phone/ Video Call from anywhere in the world to get some immediate dog training help.