Why Dogs Eat Grass | VCA Animal Hospitals (2024)

Veterinarians will tell you that they answer this question all day, every day which means lots of dogs eat grass. Eating “strange” non-food items (like grass) is technically known as pica and may be associated with a diet deficient in nutrients, vitamins, or minerals. But dogs on well-balanced, commercial diets should not be nutritionally deficient, so why do they eat grass?

The question may be simple, but the answer is not.

Is eating grass a physical need?

One common assumption is that dogs eat grass to relieve upset stomachs. Some dogs consume grass with urgency, then vomit shortly afterwards. Here is the chicken vs. egg dilemma: Does a dog eat grass to vomit and soothe an ailing stomach or does he develop a stomachache and vomit because he ate grass? Since studies show that less than 25% of dogs vomit after eating grass, it is unlikely that they turn to the green stuff as a form of self-medication. In fact, only 10% of dogs show signs of illness prior to eating grass. The bottom line is that the majority of grass-eating dogs are not sick beforehand and do not vomit afterwards.

However, there may be another digestive need filled by grazing. Dogs need roughage in their diets and grass is a good source of fiber. A lack of roughage affects the dog’s ability to digest food and pass stool, so grass may actually help their bodily functions run more smoothly.

Caution: If your turf-munching dog shows signs of stomach discomfort, he may have a medical problem such as gastric reflux, inflammatory bowel disease, or pancreatitis. See your veterinarian to rule out serious medical conditions and receive appropriate treatment.

Is eating grass a psychological need?

A dog’s day focuses on his owners’ activities, watching them leave and anxiously awaiting their return. Although most dogs enjoy being outside, some get bored when alone and need to do something to pass the time. Nibbling grass that is readily available helps fill the hours.

Dogs crave human interaction and may try to get their owners’ attention through inappropriate actions like eating grass if they feel neglected. In addition, anxious dogs eat grass as a comfort mechanism much like nervous people chew their finger nails. Whether dogs are bored, lonely, or anxious, it is often noted that the grass eating increases as owner contact time decreases.

What can owners do for these grazing dogs? For anxious dogs, a new toy or an old t-shirt with his owner's familiar scent may provide a modicum of comfort. A food-containing puzzle toy that challenges the dog will provide mental stimulation and relieve boredom. More active dogs benefit from more frequent walks and strenuous play time. For dogs that crave socialization with other canines, doggie day care may be a good option.

Is eating grass instinct?

Your dog’s ancestors did not eat kibble packaged in sealed bags. Dogs in the wild balanced their diets by eating what they hunted—all of what they hunted including meat, bones, internal organs, and stomach contents of their prey. Eating an entire animal provided a fairly balanced diet, especially when the prey’s stomach contained grass and plants that fulfilled the dog’s need for fiber.

Dogs are not true carnivores (strictly meat eaters), but they are not exactly omnivores (meat and plant eaters) either; dogs in the wild consume anything that helps fulfill their basic dietary requirements. Examining stool samples shows that 11-47% of wolves eat grass. Modern dogs do not have to hunt for their food, but that does not mean that they have lost the natural instinct to scavenge. Some dogs, even those that love their commercial dog food, will eat grass as a reflection of their ancestry and the need to be scavengers.

For these dogs, eating grass is a behavior problem that really may not be a problem at all. You need not worry if the occasional grazing session does not make your dog sick and consistent parasite prevention is provided (intestinal parasites may also be consumed with grass). In fact, behavior modification may interfere with natural instincts and do more harm than good.

Do they like grass?

Despite the numerous well thought-out explanations for why dogs eat grass, we cannot overlook the simplest explanation of all, that just like it. Dogs may simply enjoy the texture and taste of grass in their mouths. In fact, many dogs are grass connoisseurs that prefer to eat grass in the spring when it is newly emerging.

How do I stop my dog from eating grass?

Regardless of why your dog eats grass, it is not the best snack for him. While the grass itself may not be harmful, the herbicides and pesticides sprayed on it can be toxic for your dog. Also, when plucking the grass from the ground, your dog may ingest intestinal parasites such as hookworms or roundworms that contaminate the grass in fecal residue from other dogs. So, how do you stop the grazing?

Dogs that respond to food treats may be trained to stop the grass eating in exchange for a better option. That means you need to bring treats along when you take your dog for a walk and accompany him on potty breaks. Any time the dog leans down to nibble grass, distract him by directing him to walk in another direction or offer a verbal correction and offer a treat when he complies.

Dogs that are driven by affection can be trained using the same method as above by simply substituting positive verbal reinforcement and petting as rewards. Dogs that respond to verbal commands may require a simple “heel” command to interrupt the grassy snack and re-direct their attention.