Why Does My Dog Keep Eating Grass?

You’ve probably seen your dog eat grass at least once before. And even though it’s a pretty common behavior for dogs, you might wonder: Why do dogs eat grass at all — and does it mean that they're feeling ill?

There are actually a few reasons why dogs might eat grass, and some are more serious than others.

We spoke to Dr. Jamie Richardson, the medical chief of staff at Small Door Veterinary, to find out why dogs eat grass.

Grass-eating behavior is actually pretty common in dogs — in one study of 47 dogs, about 79 percent of them ate grass after being exposed to it.

But the reason for this behavior is still unknown.

“There isn’t really a definitive answer to why dogs eat grass,” Dr. Richardson told The Dodo. “There are several theories.”

Here are some theories about why dogs eat grass, according to experts.

One theory is that dogs eat grass when they’re feeling sick, since the behavior is sometimes followed by vomiting.

But it’s not certain whether dogs eat grass when they’re feeling sick or if they get sick from eating grass — kind of like a chicken-or-egg scenario.

But since less than 25 percent of dogs actually throw up after eating grass, it’s still unclear whether gastrointestinal issues are the main cause of grass-eating behavior in dogs.

“This is a widespread theory and may be true in some cases, but fewer than a quarter of dogs vomit after eating grass,” Dr. Richardson said.

Sometimes pica (aka eating non-food items) is caused by diet deficiencies.

“Some theories claim that it fulfills an unmet nutritional need for fiber or other nutrients,” Dr. Richardson said.

So if your dog isn’t getting enough fiber in his dog food, for example, he could be craving grass to help with his digestion.

Or if you’re not feeding your dog enough, he could be eating grass because he’s still hungry after meals.

If you think your dog might be eating grass because of nutritional problems, talk to your vet to see if they recommend changes to your dog’s diet or supplements.

Dogs who are bored or anxious will sometimes do weird things to entertain themselves or relieve their anxiety — and eating grass may be one of those things.

“Dogs may eat grass out of boredom, due to stress or obsessive compulsive disorder,” Dr. Richardson said.

If your dog is eating grass as an anxious behavior, he’ll likely have other signs of stress or anxiety, too, such as licking, hiding, aggression or other repetitive behaviors.

Eating grass may also just be an instinct for your pup.

Wild dogs, such as wolves, eat grass (and eat prey who eat grass), so your dog may be craving it because it’s a part of his ancestors’ diet.

It’s possible that your dog just likes the taste or texture of grass or smells something else yummy in the grass.

Dogs have a super strong sense of smell, so he might smell something left over in the grass that you can’t detect, “such as a picnic,” Dr. Richardson said.

While not all dogs get sick after eating grass, some dogs do. But this isn’t because the grass is toxic.

“If the gastrointestinal system detects something inedible (such as a large volume of grass), the body may react by attempting to remove the material via vomiting,” Dr. Richardson said. “If only a small amount of grass has been consumed, your dog may be less likely to vomit.”

So you don’t need to worry about the grass itself being toxic (unless there’s something in it, like pesticides). Your dog might just throw up from eating too much, similar to how you might if you eat way too much at dinner.

If your dog eats a tiny bit of grass every now and then, it’ll probably be fine. But it could quickly become a serious problem if your dog starts to eat a lot — so you should try to stop the behavior before it escalates.

“If your dog ingests a large amount of grass, it could lead to a life-threatening intestinal blockage, which could require emergency surgery,” Dr. Richardson said.

It could also be a problem if there are poisonous substances in the grass or other dangerous plants in the area, Dr. Richardson said. Some things to watch out for include:

If your dog’s eating grass excessively or starts having abnormal symptoms, you should take him to the vet to get him checked out.

“Ingestion of a small amount of grass and/or a single episode of vomiting may not warrant veterinary care,” Dr. Richardson said. “However, if a dog repeatedly vomits or gags without bringing anything up, has diarrhea, seems in discomfort or is lethargic, they should be examined by a veterinarian immediately.”

But if you think your dog just loves to have grass as a snack, you can give him a safer alternative (and limit how much he can eat).

“If you believe they may simply like the taste, you could try giving them a few leaves of spinach or another leafy green to see if that satisfies their craving,” Dr. Richardson said. “You may feel more comfortable feeding them greens you’d eat yourself as opposed to random greenery they find outside!”

You can also grow your own pet-safe grass, like this pet grass kit from Chewy for $6.

“To help prevent boredom, increase the amount of exercise and playtime your dog is getting each day,” Dr. Richardson said. “You can also provide interactive toys, such as food puzzle toys, to provide mental stimulation, especially when they are home alone for longer periods of time.”

This interactive dog toy earned The Dodo’s Paw of Approval, and you can get it from Fable for $55.

If your dog’s eating grass because he’s stressed or anxious, trying to relieve those issues might resolve his grass-eating tendencies.

“Natural therapies and products can also help with anxiety, including calming aids like pheromone collars (Adaptil) or products like the Anxiety Wrap or ThunderShirts,” Dr. Richardson said. “For severe stress/anxiety issues, you may need to enlist the help of a behavioral specialist, who can assist with techniques such as desensitization and counterconditioning.”

You can get the Adaptil calming collar from Amazon for $22 and the ThunderShirt from Amazon for $50.

According to Dr. Richardson, some other ways to stop your dog from eating grass include:

Even though a little bit of grass is OK every now and then, be super careful that he’s not eating too much, and make sure there are no pesticides on the grass. And if you think there’s an underlying reason for why your dog is eating grass, contact your vet.

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