The question of “Why do dogs eat grass?” has puzzled many pet owners and veterinarians over the years. Theories abound, but the truth is no one is 100% certain why dogs seem to like to munch on the green stuff. Obviously, your dog is not a cow or goat, so running around the yard eating grass seems like fairly weird behavior for a canine.

Plus, most dogs that eat grass promptly vomit it back up, and then go back to eating more grass! As a pet owner, you might wonder if your dog is sick, has an upset stomach, or perhaps bored, or you might even wonder if you are feeding them enough. Are they hungry? Are they eating grass because they aren’t getting enough food? Why do dogs eat grass and then throw up right after?

To a pet owner who has never seen such behavior, this can be confusing and possibly even worrisome. Rest easy however, most vets and experts agree that though the behavior seems odd, it actually appears to be a natural inclination for dogs. And for the most part, it doesn’t seem to hurt them.

In mental health terms, there is a disorder called pica that is characterized by the subject eating material that isn’t food. It’s seen frequently in humans, when kids eat glue for instance, but it can also be seen in dogs.

Fortunately, as long as the grass or plant your dog is eating isn’t toxic, or coated in toxic chemicals, then it shouldn’t really harm them. Again, there are a variety of “theories” as to why dogs eat grass, but no one has a definitive answer. Keep reading as we explore some of these theories more in depth.

Boredom

Some experts believe dogs eat grass merely out of boredom. If your dog isn’t getting enough exercise or feeling challenged on a regular basis, they may look for ways to keep themselves entertained and pass the time.

For instance, if your dog is left outside alone for long periods, or if you aren’t giving him much one-on-one attention and playtime, you may notice him eating grass more frequently. Sometimes, just making sure they have toys and bones to entertain themselves can help curb grass eating.

It Simply Tastes Good

It’s true that some dogs might just like the taste of grass. No accounting for taste, right? Dogs are natural little scavengers, and it’s possible there’s something about that particular blade of grass that tastes good to them, for whatever reason.

It’s also possible that your dog is instinctively looking to add additional fiber to his diet, that perhaps the food he is eating isn’t giving them. You can try switching his dog food to something that is higher in fiber, and see if that reduces the behavior, or try adding foods with fiber to his current diet to make it into a high-fiber diet.

Gastrointestinal Upset

Some experts believe dogs may eat grass as a way to relieve gastrointestinal upsets, such as gas, bloating, and canine nausea, or as a natural way to improve digestion. Other experts don’t believe dogs are smart enough to treat themselves for an upset stomach. Plus, dogs don’t typically appear to be sick before they eat the grass and vomiting after they eat grass isn’t as common as you might think.

Instinctive Behavior to Induce Vomiting

Though it’s not as common, some dogs do eat grass and then throw up. When dogs vomit after eating grass, it is believed to occur because the dog ate and swallowed the grass quickly, without fully chewing it, if they chewed it at all.

This is thought to possibly be an instinctive behavior they do in an effort to force themselves to vomit. The theory is, when they swallow the grass quickly, the long blades of grass tickle their throat and the lining of their stomach and induce the urge to throw up.

Possible Parasites

Some experts believe that dogs eat grass as a way to treat canine parasites like intestinal worms. This predilection could be inherited from their wild wolf ancestors. As grass and plant materials are digested and run through the intestinal tract, it provides fibrous bulk to help keep the bowels moving properly.

As the grass and plant material moves through the intestines and bowel, it wraps around intestinal parasites to move them out of the body. While most domesticated dogs are worm-free, that doesn’t take away the natural instinct that may have been passed down from their ancestors.

Possible Nutritional Deficiency

Some experts believe dogs eat grass as a way to fill some unknown nutritional deficiency that their bodies instinctively know they are lacking. That malnutrition in dogs could be fiber, or something else.

The best way to make sure your dog is getting the nutrition he needs is to make sure you are feeding him a high-quality diet. You want to make sure what you give him is a fiber and nutrient-rich food that satisfies his nutritional requirements. What the food itself doesn’t provide, you can also try giving him certain supplements to bolster your dog’s health and longevity.

Will Eating Grass Hurt My Dog?

As a dog owner, you may be wondering if eating grass is dangerous for your dog. In general, allowing your dog to eat grass will not hurt him. However, eating toxic plants such as certain weeds and flowers can be harmful to your dog’s health. Certain annuals, perennials, shrubs, vines, and even trees can be toxic to animals, including dogs. There are also tropical plants and bulb plants that dogs shouldn’t eat as well.

You also want to make sure your dog is not eating grass that has been treated with pesticides, weed killers, or fertilizers, as these can all be poisonous agents and cause more harm than good. If you suspect your dog has eaten something toxic, you should contact an animal poison control center as well as your local vet.

If your dog persists in eating grass on a regular basis despite vigorous discouragement and distraction tactics, you may want to just buy him grass that is safe for him to eat. Direct him to the grass you have purchased and keep him away from potential greenery that has been chemically treated.

Should You Stop Your Dog from Eating Grass?

In most cases, you shouldn’t worry too much about your dog’s eating grass habits. It’s considered a natural behavior, and is usually benign, as long as it doesn’t stem from or become an obsessive compulsion.

However, if you think your dog is eating grass out of boredom, if the behavior appears to be obsessive, or if you think there is some underlying cause such as illness, nutritional deficiency, or intestinal parasites, then you should take your dog to the vet for a checkup, just to be safe.

You can decide on a course of action from there. Sometimes making sure your dog has lots of toys to play with and plenty of opportunity for exercise can eliminate a problem that is born of boredom. In other cases, tweaking your dog’s diet can eliminate grass eating, since a well-balanced diet can also solve your dog’s possible nutritional deficiency. You know your dog best, so trust your instincts.

Tips to Stop Your Dog from Eating Grass

If your dog’s grass eating behavior bothers you, there are a variety of things you can try to help discourage him. Depending on why your dog is eating the grass in the first place, these tips may or may not be helpful.

Try Giving Him a New Food

Because many experts believe that dogs eat grass as a way to make up for some sort of nutritional deficiency, one of the most common ways pet owners will attempt to discourage that behavior is by tweaking their diet and changing his food.

This is especially true for dogs that eat foods like canned or dry kibble, instead of a fresh, raw diet. You can look for a high-quality dog food that is rich in fiber, although nothing beats a fresh and raw way of eating. Gradually, over the course of several days, you can change your dog’s food by mixing the new food in with the old food. Simply adjust the ratios a little more each day, until your dog is eating 100% of the new food on the last day.

Changing his food slowly in this manner can help him avoid any tummy upset that sometimes occurs from a sudden change. When looking at dry dog food and kibbles, search for brands with ingredients like rice, soybean, or peanut hulls, bran, beet pulp, and pectin as their fiber sources.  

Another way to give your dog more fiber in their diet is to feed them steamed vegetables. Dogs can safely eat steamed green beans, zucchini, squash, potatoes, celery, spinach, peppers, as well as carrots and broccoli. You will have to test these veggies to figure out what your dog likes best.

Steamed veggies can be included as a regular part of meals, or you can offer them as treats. You can also offer your dog raw veggies, especially things like broccoli, spinach or shredded carrots, as a way to sort of “fool” your dog into thinking they’re eating grass. Ultimately, eating the green stuff just comes naturally for a dog, so try not to be too alarmed by the occasional nibble, as long as you know the source is safe.

Keep Them Busy

Another way to possibly discourage your dog from eating grass is to keep him busy. If your dog is eating grass out of boredom, try giving them toys or chew sticks to keep him occupied. Make sure that any bones or chew toys you give your dog are natural, such as rawhide or beef bones, or non-rawhide chew toys made from chicken and veggies.

You can also give them nylon bones and chew toys if they really like to go to town, since nylon is sturdier and holds up longer. Dental bones can also be a good choice to keep your dog busy and get in a little teeth cleaning in the process.

If your dog doesn’t care for bones, try offering him other toys to play with, like stuffed animals, tennis balls, rope toys, hard rubber toys, or “busy box” toys that you can hide treats inside of. Some pet owners like to offer their dogs old dirty laundry with their scent on it.

You can also keep your dog busy with regularly scheduled activities and playtime, such as a long daily walk, a regular date to play fetch, a long run, or a regular trip to a dog park. The key with exercise and activities is to try to schedule them around the same time each day, so that your dog learns to anticipate playtime.

Avoid Problem Areas

Sometimes, you may find that your dog only tries to eat the grass found in a certain spot. The best way to prevent this is to keep them away from that area entirely, if possible. Maybe that means walking him on a leash, or taking him to a different dog park, or sectioning off an area of your yard that you want him to stay out of. Sometimes prevention is the perfect remedy for undesirable behaviors.

At the end of the day, simply doing your best to keep your dog happy, healthy, and active can go a long way in curbing his penchant for eating grass. By keeping him stimulated and engaged, you will be able to drive away his dirty habit of eating grass.