Why Is My Dog Eating Grass?

Grass eating is one of the most common behaviors in dogs — studies show up to 80% of dogs eat grass regularly. Despite the popular belief that dogs eat grass to make themselves vomit when they feel sick, research suggests most grass-eating dogs are not ill beforehand and don't vomit afterward.

The most likely explanations: instinctive behavior inherited from wild ancestors (wolves eat plant matter as part of their natural diet), a source of fiber that aids digestion, simple enjoyment of the taste and texture (many dogs seem to specifically seek out certain types of grass), and sometimes boredom or anxiety.

However, there is a distinct pattern of grass eating that does indicate nausea: frantic, urgent grass consumption — the dog seeks out grass with an almost desperate intensity, eats it rapidly, and vomits shortly after. This type of grass eating is different from the casual grazing described above and may indicate stomach upset, acid reflux, or an underlying GI problem.

Potential concerns with grass eating: pesticides, herbicides, and fertilizers on treated lawns are toxic. Grass can carry parasite eggs (roundworm, hookworm) from other animals' feces. Some grass-like plants are actually toxic (foxtails can lodge in the throat or nasal passages).

If your dog is a casual grass nibbler on your own untreated lawn, it's almost certainly nothing to worry about. If the grass eating is new, frantic, or accompanied by other symptoms, it warrants attention.