Experts and owners theorize about why some dogs graze on grass like cattle do. Some people think it’s a sign of an upset stomach, and the grass is soothing. Some dogs just like the taste of it. Others think some dogs just like to have something in their mouths. Retrievers and other dogs who love to carry things in their mouths seem to be particularly fascinated with grass.

Dogs’ stomachs, however, are not always so thrilled with grass. Dogs often vomit up the grass a few minutes after eating it. Bigger dangers lurk if the grass is chemically treated, which makes the green stuff potentially toxic to your pet.

Teaching your dog to curb his appetite for grass requires attention and training. If your dog likes to eat grass, try adding fresh green vegetables to his food (making sure to avoid onions).