Why Does My Dog Eat Grass and How Do I Stop It?

white lab dog laying in tall grass while eating it

To some dogs, a thick, green lawn looks like an all-you-can-eat salad bar. If your dog is a grazer, don’t worry. Eating grass is a perfectly normal canine behavior, and there’s nothing wrong with it nine times out of ten. 

However, in some cases, a sudden hankering for grass could indicate a health problem or a diet that’s lacking in nutrients. We can’t say for sure, since the reasons why dogs eat grass are shrouded in mystery. But we’ll go over some of the most common, scientifically supported theories behind the behavior, followed by advice on how to stop it.

Whatever reason your dog eats your grass, one thing is certain: Those nibbles won’t be enough to cause significant damage to your lawn. If it’s lawn damage you’re worried about, the real problems are dog urine and feces

Theories on why dogs eat grass

Why do dogs eat grass? There’s no clear consensus among veterinary experts, but there are a lot of educated guesses. Pay attention to your dog’s general behavior to figure out which one of these popular theories could be the reason behind her grazing. 

Dogs eat grass to settle an upset stomach

One common suggestion is that dogs eat grass when their stomach gets upset to make them vomit. After they puke up whatever was making their tummy hurt, they’ll feel better. 

If this is the case for your dog, you’ll probably notice him acting sick before grazing. Look for things like unusually lethargic behavior, loss of appetite, severe gas, rumbling tummy, or runny poop.

Dogs who eat grass as the result of an upset stomach only do so occasionally. If your dog is a regular grazer, this theory probably doesn’t apply to her. 

Even though this theory is popular, research suggests gastrointestinal issues aren’t a common reason for dogs to eat grass. One study from UC Davis School of Veterinary Medicine found that, based on their pool, only 9% of grass-eating dogs act sick before grazing, and only 22% of dogs vomit right after eating grass. 

Dogs eat grass because of a nutritional deficiency

Another reason dogs might eat grass is that they aren’t getting all the nutrients they need from their dog food, especially fiber. Grass leaves, like a lot of edible plant matter, contain fiber. 

The evidence seems to back up this theory. In one case, a miniature poodle regularly ate grass then vomited it up for seven years. After switching to a high-fiber diet on advice from a veterinarian, she stopped eating grass completely. 

Like that poodle, your dog may be trying to tell you that he needs a type of dog food with more fiber. Before switching your dog’s food, consult your veterinarian to make sure it’s the right move. 

If you decide to make the switch to high-fiber dog food, don’t do it all at once. Make a gradual transition from the old food to the new one to prevent vomiting, diarrhea, or upset stomach (which could lead to more grass-eating). 

Dogs eat grass because they’re bored

Dogs sometimes resort to destructive behaviors (like chewing up your brand new shoes) when they’re bored. They may be seeking attention, or they may just want something to do. Grass eating could be one of those behaviors that stems from boredom. 

Dogs get bored when they don’t get enough exercise and mental stimulation. If you think your dog might suffer from boredom, try:

  • More frequent or longer walks
  • Interactive play with a chew toy, frisbee, or ball 
  • Agility courses (which you’ll often find at public dog parks)
  • Training your dog to do new tricks 

If boredom is the cause of your dog’s grass-eating, the behavior should stop once your dog gets more exercise and interaction with you. 

Dogs eat grass to satisfy a natural instinct

Unlike cats, dogs aren’t carnivores. They’re omnivores (like us) which means they eat both meat and plant matter. That’s why many dog foods contain grains, vegetables, and fruits. 

Even wild dogs eat plants sometimes. Domesticated dogs may have inherited that instinct from their wild ancestors. They may eat your grass as a way to satisfy the urge to “scavenge” for plants (as opposed to “hunting” for meat, which they already get in their regular diet). 

You can’t change your dog’s instincts, but you can try to train her to ignore them if necessary. We’ll talk about how to train your dog to stop eating grass later in this article. 

Dogs eat grass because they’re anxious

Grass-eating in and of itself isn’t a sign that your dog is anxious. However, dogs who suffer from anxiety or obsessive-compulsive disorder (OCD) sometimes develop “pica.” Pica is a medical term for the act of eating something other than food, which includes grass and dirt. 

Casually nibbling on the grass from time to time is NOT a sign of anxiety or OCD. If your dog’s grazing stems from a deeper psychological issue, you’ll notice these traits:

  • You can’t stop your dog from trying to eat grass, even with physical restraint.
  • As time goes on, your dog eats grass more often or spends a longer amount of time eating grass.
  • You see signs that your dog is hurting himself, such as missing fur, raw skin, or the tip of the tail missing. 

If you think your dog might have anxiety or OCD, consult your veterinarian for diagnosis and treatment options. 

Dogs eat grass because they like the taste

Some dogs may eat grass just because they like the taste and feel of it in their mouth. There’s no way to prove scientifically that dogs enjoy eating grass, but it’s the only apparent explanation in many cases. 

It might seem odd that dogs would enjoy an activity that makes them sick sometimes, but think of it this way: How many lactose-intolerant people have you met that still eat cheese or ice cream all the time because they love it so much? 

Still, as a pet parent, you don’t want to let your beloved canine companion eat grass if it always makes her vomit. Depending on your dog, you may be able to train her to stop. More on that below.

How to stop your dog from eating grass 

As we mentioned earlier, eating grass is an extremely common behavior in dogs, and it’s usually harmless. Training your dog to stop grazing might not be worth the effort. 

However, there are some cases when stopping the behavior could be necessary to protect your pup’s health.

Should you stop your dog from eating grass?

You only need to worry about your dog eating grass if:

  • It usually makes him throw up
  • You use any chemicals on your lawn (such as pesticides, herbicides, fertilizers, or fungicides)
  • You take your dog to a park or other public space where there might be chemicals on the grass
  • Your dog eats other plants that might be toxic (check the ASPCA’s list of toxic plants to find out if you have anything dangerous growing in your landscape)
  • You or your neighbors don’t pick up dog poop in your yard (even tiny traces of dog poop can contain bacteria or intestinal parasites such as hookworms and tapeworms)

If none of the above conditions are true, there’s no harm in Fluffy taking a bite of your grass every now and then or even every day. 

Training your dog not to eat grass 

In cases where eating grass is bad for your dog’s health, here are some training methods you can try to get her to stop:

  • Food-motivated training: When you go for a walk, bring along your dog’s favorite treats. Any time he veers off the walking path or starts to eat grass, call him back to you and offer him a treat.
  • Affection-motivated training: Some dogs respond better to affection than food. If that’s the case for your dog, then any time you’re out for a walk and she starts to eat the grass, call her back to you and shower her with pets and praise. Establish a phrase such as “good job” or “yes” that she will learn to recognize over time as a good thing. 
  • “Heel” command: The “heel” command teaches your dog to walk parallel to your left side with no more than 6 inches between you. Once your dog masters the heel command, you’ll be able to keep him from getting distracted by grass or anything else on your walks. Learn how to establish the heel command in this guide from the San Francisco SPCA.

Keep in mind that how your dog responds to training and how long it takes for commands to stick depends entirely on the dog’s individual personality. 

How dogs give your lawn a grass-kicking

Dogs nibbling on grass won’t cause significant damage to your lawn, but dogs have other behaviors that can kill your grass and plants. The most common dog-related lawn damage comes from peeing, pooping, digging, and running around on the grass. 

Is your lawn riddled with brown spots and bare patches? There’s a good chance your good girl or boy is the culprit (just not because of grazing). Check out these guides for advice on how to dogproof your yard:

As long as you’re willing to work at it, it’s possible to have a lush lawn with a dog — even if your pooch treats the backyard like a salad bar.

Wishing Fido ate enough grass that you could stop mowing the lawn? Our local lawn care pros might not be as cute as your dog, but they can still take lawn mowing off your to-do list

Main Photo Credit: smerikal | Flickr | CC BY-SA 2.0

Jordan Ardoin

Jordan Ardoin is a writer and indoor plant enthusiast hailing from Florida. In her spare time, she enjoys chasing her two cats around the house and trying to keep her houseplants alive.