Your beloved canine companion clearly isn’t a cow, so you might be confused when you see him eating grass. You might even be worried. Is he hungry? Bored? Sick? Will eating grass hurt him?
First, rest assured that you’re not alone in your concern, especially if your dog is eating grass and vomiting.
Pica is the technical term for the disorder characterized by eating things that aren’t food. Sometimes pica indicates that your dog has some type of nutritional deficiency, though it is often simply a sign of boredom, especially when practiced by puppies and younger dogs.
Source: Web MD