What Causes My Dog to Eat Grass and Then Throw Up?

Dogs have a lot of behaviors you'll get to know as you raise them over time. Some of them are adorable and charming. Others are annoying. Some can be worrying. One that seemingly every dog does at some point is eating grass until they throw up.

Now, we've all been there, right? Everyone has that moment as a kid where they eat too much cake and feel sick, or gorge on holiday candy and treats, or just go too deep on whatever it is they're fixated on at the time. However, we don't usually eat until we actually throw up. And, critically, we're doing it with something we enjoy.

So, do dogs just really like eating grass? Is this a behavior we should be worried about? Let's talk about it.

Why Do Dogs Eat Grass Until Vomiting?

First up, let's talk a bit about why dogs eat grass in the first place. Then, we'll get into whether or not you should be concerned and what you should do about it.

Before getting into the actual reasons, I wanted to mention a common myth: that dogs are intentionally gorging themselves on grass to induce vomiting.

So, you know how when you have nausea, and you feel the bile rising in your throat, and your mouth starts to salivate a lot? It's a biological reaction to get you to swallow a lot of liquid to try to settle your stomach, or at least coat your mouth and throat before you vomit to protect it from stomach acid.

In dogs, the same sort of thing happens, but they don't really know how to deal with it. Most of the time, they start licking or chewing on anything nearby. If they're outside in the yard or on a walk, they'll start eating grass in an attempt to settle their stomachs, but since grass isn't really part of their diet, it can trigger their gag reflex and make them vomit.

Basically, they aren't intentionally making themselves vomit, but that's what ends up happening, and since vomiting often alleviates whatever was causing the digestive upset in the first place, it kind of works out.

Another common reason people think dogs eat grass is out of boredom, but that's not really accurate either. Dogs, when they're bored, are more likely to be destructive than consumptive. They might eat things like grass, cardboard, furniture, pillow stuffing, and whatever else they can get their paws on, but it's more of a side effect of just tearing it apart. They aren't doing it to eat grass; they're doing it as part of just doing something to get your attention.

What are the actual reasons dogs eat grass? There are basically three main reasons.

Reason #1: They just like the taste.

The first reason dogs eat grass is just because they like how it tastes.

You and I eat vegetables and (usually) enjoy them, right? Whether it's some lettuce in a salad, some broccoli or cauliflower roasted in the oven, or a nice pile of carrots and potatoes on the side, vegetables can be quite delicious.

And, of course, we all know that dogs love eating things they find tasty. Whether it's their kibble, a treat like a bit of cheese, or a pile of something weird and gross on the ground, they'll dig right in. Their tastes might not make sense to us, but to them, and the way they see the world, it's delicious.

Grass can be tasty in its own right. Even plants you might not think you would eat can be tasty in the right preparations, and to dogs, that right preparation might be as simple as "still wet from morning dew or a rainstorm" or "covered in the scent of other animals that ran through here."

It also ties into the second reason; after all, when you evolve to do something, you probably evolve to at least find it palatable.

Reason #2: It's an instinctual behavior.

Dogs are a distant offshoot of wolves, and wolves also eat grass. They do it for many of the same reasons, but also, it's just part of hunting. Sometimes, they need something moderately nutritious to fuel them while they hunt prey. Sometimes, when they take down prey, as they eat the meat, they end up with mouthfuls of grass as well. They can't necessarily afford to be picky eaters, so they take what they get.

A lot of times, dogs just have this need to eat grass as they pass by. There doesn't really need to be a deeper meaning to it at all; it's just something they do because their little goofy brains tell them it's a good idea.

Reason #3: They have an upset stomach.

I already covered this one above in a roundabout way. Dogs don't really have the drive to eat grass to satisfy an upset stomach, but if they're feeling nauseous, they might want something to try to keep it down. If they don't have access to grass, maybe they'll just start licking the carpet, or they'll go and drink a bunch of water.

And, truth be told, sometimes it works. In fact, while the experience of a dog eating grass and then throwing up seems universal, studies have shown that only around 10% of dogs show any sign of being ill before they eat grass, and only a quarter of them vomit after eating grass. You might even be able to attribute the vomiting to over-eating in general or to eating something on the grass that disagrees with them.

In a way, it's a lot like how we can settle our stomachs with neutral crackers or digestives or something else that can soak up churning stomach acid and help the system move a little faster.

Should You Worry If Your Dog is Eating Grass?

Honestly, probably not!

It's fairly natural for dogs to eat grass from time to time. Some of them will want to eat grass pretty often, maybe on every walk or every chance they get. Others might only think of it as a sometimes snack, taking mouthfuls of a tasty grass they find along the way but generally leaving it all along.

There are a few good reasons why you might want to do some redirection training and help keep your dog from eating grass too often, though.

• If they eat too much grass, it can fill them up, so they won't eat their normal food and can end up deficient.
• If they eat too much grass, it can cause an upset stomach and lead to problems.
• They might eat things along with the grass that they shouldn't, whether it's sharp bits of wood, stinging plants like nettles, plants like poison ivy that can cause a bad reaction, or things like stinging insects that can cause other problems.
• The grass they eat might have chemicals or other nastiness on it that can be dangerous for your dog, even if the grass itself is not.

Overall, if your dog is eating grass, you should look at the situation and figure out why they're doing it and if it's cause for concern. If it's sporadic or occasional and doesn't seem to cause them any problems, you can leave it be.

If they're eating grass while also doing things like digging holes or tearing up the carpet, it probably means they're bored. They might also do things like eat your houseplants, which is also obviously not something you want them to be doing.

Boredom means that training isn't likely to work since it doesn't address the cause of the problem. You'll simply need to find ways to keep your dog entertained and engaged, even when you're not around. That might mean hiring a pet sitter for the day, or a dog walker, or getting friends to hang out and care for them. Alleviating boredom and the anxiety that comes with it is the key.

If your dog seems to have a compulsion to eat grass and they seem to be fixated on it whenever you take them out, there are two things you can do.

The first is to take them to the vet to see if there's actually something wrong with them. It's pretty rare for this to be the case – your fur baby isn't going to be eating grass as their sole symptom, so you'd be able to recognize if they're sick in other ways – but it's possible. A rare disorder called pica, or disordered eating, can lead to dogs trying to eat just about everything they see, including grass. Other medical issues, like gastric reflux, IBS, or pancreatitis, can also lead to eating grass. It's a good idea to rule these out.

The other thing you should do is try redirection training. Redirection training just means that whenever you see your dog start to lean over to eat grass, you give them a call or command to distract them and reward them for not eating the grass. I find that a "drop it" command can be pretty effective.

If you do this consistently enough, they'll attach the reward in their mind to the act of refraining from eating grass, and they'll stop. You do need to be consistent and proactive with it. It will take some time, just like all dog training, but it's not actually all that hard to do.

Overall, though, unless your dog has accidentally poisoned themselves, gotten themselves sick or parasitized, or is eating so much that they cause problems, you probably don't need to worry about them eating grass. Sometimes, the things dogs do are just things dogs do, and they aren't a sign of anything worse.

Another thing you can try is changing their food. There was one recorded example of a dog that ate grass to the point of vomiting every day for years, and it turned out to be something with their food that disagreed with them. When their parents changed their food, they stopped eating grass, and everything was good. That might not be the case for your dog, but it might be worth a try.

Dog Grass Eating FAQ

Now, let's round things out with a few questions you might have that didn't fit into the main sections.

Do dogs like eating grass?

Maybe! Like most things, your dog is an individual, and they have their own preferences. Some dogs don't care about grass one way or the other. Some prefer to avoid it when they can. Some like the texture or the taste of the grass. Some might not actually be going after the grass itself, but rather, some kind of chemical or fertilizer or a specific plant in the grass, like clover. If you notice that your dog eats grass a lot more in the spring, that's likely it; fresh grass shoots and wildflower sprigs are sweeter and more tender, while later summer and fall grasses are rougher and more likely to be bitter.

Is grass bad for dogs to eat?

Only in excess. Dogs are omnivores just like we are, so just like we can eat some vegetables in our diet, dogs can have a little grass as a treat if they like. Cats are the same way, though they aren't quite the same kind of omnivore.

That said, if they eat too much grass, it can cause problems, so you should probably try to train away that behavior as much as you can. You don't need them to fully stop; just not eat to excess.

More importantly, though, even if the grass isn't bad for your dog, you never know what's in the grass. There could be toxic fertilizer, pesticides, roadside chemicals, and even parasites that can come along for the ride. If you keep your yard free of contaminants, you may be fine, but it's best to be safe.

Is eating grass a sign of nutritional deficiency?

While this is a pretty common myth, it's actually just that: a myth. For one thing, if you're feeding your dog right, they won't be nutritionally deficient in the first place. More importantly, if they are deficient in some nutrient or another, they'll have symptoms of that deficiency, usually weight loss, lethargy, loss of coordination, or another sign of illness.

Overall, you generally don't need to worry about your dog eating grass, even if they vomit after doing it. It's only if they do it over and over and over that it might be an issue, but even then, it's unlikely to be an emergency. Just mention it next time you bring them to the vet, and work on some training along the way.

As always, if you have any questions about anything I covered in this article, be sure to let me know in the comments section!