Why Does My Dog Eat Grass?

Dogs Eat Grass Because They Like It

The most common reason dogs eat grass is simple: they like it. The term for eating nonfood items like grass is “pica,” and dogs often do it for the taste, texture, or crunch. Some may even enjoy the moisture in grass, especially on hot days when water isn’t available. This behavior is natural and not necessarily linked to illness.

Passages from *Big Kibble* and *Shih Tzu Dogs* both confirm that grass eating is common and often just a matter of preference. One poodle stopped eating grass after switching to a high-fiber diet, suggesting fiber might play a minor role—but no strong evidence supports this as a primary cause.

Does Grass Make Dogs Vomit?

A common myth is that dogs eat grass to make themselves throw up. However, studies show this is unlikely. In a 2008 survey of 1,571 dog owners, only 22% reported vomiting after grass eating. A controlled experiment at the University of New England found that vomiting occurred only five times in 709 grass-eating events.

Another study found dogs actually ate more grass when fed a standard diet than when given a supplemented one—contradicting the idea that they eat grass to relieve digestive discomfort. While some dogs may vomit after eating grass, it’s not a consistent or reliable trigger.

Could Grass Help with Digestive Health?

Some scientists believe dogs eat grass to purge their guts, similar to how wild animals like wolves and apes use it to expel parasites. Wolves have been observed eating grass, and their scat often contains roundworms or tapeworms. This suggests grass-eating may be an inherited behavior from wild ancestors.

Dogs may also eat grass to clear out non-digestible items like toy parts or other foreign objects. While not all experts agree, the purging hypothesis is considered the most likely explanation for grass consumption in dogs.

When to Be Concerned About Grass Eating

Eating grass is generally harmless if the grass is free of pesticides or chemicals. However, if your dog suddenly develops a strong obsession with grass, or if grass eating is accompanied by vomiting, diarrhea, or weight loss, it could signal an underlying issue.

Possible concerns include parasites, inflammatory bowel disease, food allergies, or food sensitivities. In such cases, a vet visit is recommended to rule out gastrointestinal problems.

Keep Grass Safe and Monitor Behavior

As long as the grass is clean and untreated, occasional grass eating is normal and safe. Dogs are natural scavengers and have long been on the lookout for food. However, if you notice a sudden change in behavior—like eating grass constantly or showing signs of illness—it’s best to consult your veterinarian.