Why Do Dogs Eat Grass? All Info

Why Do Dogs Eat Grass? All Info. Why Do Dogs Eat Grass? All Info. It is not uncommon to see your dog grab a mouthful of grass during their daily walk or a romp through the park. Ever wonder why dogs do that?

Many people believe that when dogs eat grass, they are trying to make themselves vomit. They think it’s an instinctive behavior that a dog engages in to rid themselves of something they should not have eaten.

And some think that it’s an indication that their dog has an upset stomach or intestinal problem.

Reasons Dogs Eat Grass

There have been many speculations and theories, but there is limited research on why dogs eat grass. So the truth is that no one knows for sure. However, scientists have formed a few theories and disproved some myths based on the research we do have.

Instinctive Behavior

Some scientists believe that eating grass is a natural behavior for dogs that comes from their wolf ancestors. We know from research on wolves that 2-10% of their stomach contents may contain plant material.

Additionally, wild canids from the Canidae family (which includes wolves, jackals, foxes, and coyotes) have also been seen to eat grass.

Supplementing a Missing Nutrient

In one particular case report, an 11-year-old Poodle had a 7-year history of eating plants and grass and vomiting afterward. The problem resolved after the dog was placed on a commercial high-fiber diet.

This was evidence that for this particular dog; he was supplementing his dietary deficiency by eating grass and plants. Once provided with adequate fiber in his diet, the grass-eating behavior resolved.

But can dogs actually digest grass? Dogs are primarily carnivores, meaning they eat meat. However, recent studies have shown that dogs have evolved the ability to digest some carbohydrates in response to coevolving with humans.

Carbohydrates are sugar, starches, and fibers mainly found in fruit, grain, vegetables, and milk products. If dogs can digest some carbohydrates, then does this mean our dogs can really digest grass? The answer is no, not really. Grass mainly passes through the dog’s intestinal tract undigested.

Normal Dog Behavior

In another study, Bjone et al. (2007) found that grass-eating behavior in dogs is influenced by hunger and the time of day. Dogs were less likely to eat grass after a meal, and more likely to eat grass before a meal.

Grass-eating also decreased later in the day. The researchers believed that grass eating is normal dog behavior and is not indicative of an underlying illness.

Soothing an Upset Stomach

McKenzie et al. (2010) designed a study that fed one group of dogs a diet containing fructo-oligosaccharide (FOS) while the other group was fed a standard diet. FOS comes from sugar beets and passes through the small intestines undigested into the large intestine where it ferments.

Dogs who were fed large quantities of FOS typically had watery, loose stool. The dogs who were fed the standard diets had more episodes of grass eating compared to the FOS dogs that had diarrhea. This meant that dogs with gastrointestinal upset were less likely to eat grass.


Dogs, especially younger dogs, often explore with their mouths. Eating grass may be something that they try, just like some children eat dirt. Some dogs may learn to like the taste of grass.

Attention From Pet Parents

Some dogs learn that when they eat grass, their owners give them more attention. This may be in the form of you talking to your dog more, or offering them treats as a way to get them to stop eating grass and eat the treats instead.

However, sometimes pet parents pull their dogs away from grassy areas, which may only spur the dog to eat more grass as soon as they find it because it’s now forbidden.

Does Grass Make a Dog Vomit?

Bjone et al. (2007) also recorded episodes of vomiting in their study. There were 5 episodes of vomiting out of 709 grass eating incidents. This study concluded that dogs do not eat grass to cause themselves to vomit.

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