Why your dog is trying to eat grass: Debunking the myths

Although dogs are omnivores, most dogs are not known for being fond of salad or greens. Yet a surprising number of dog owners find themselves asking, “Why is my dog trying to eat grass?”.

You may be wondering if your dog is sick or if eating grass is a sign of a bigger problem. If you see undigested plant material in your pet’s vomit or stool, do your best to look at it closely so you can tell if it truly is grass. Vomiting and diarrhea are the most common early symptoms of ingesting a toxic plant, but if it’s clearly just grass, there’s nothing to worry about. Eating plain grass that hasn’t been treated with chemicals is not dangerous for your dog. Since a dog isn’t capable of thoroughly digesting grass, it’s not unusual to see grass in vomit or stool, which begs the question: why do they eat it in the first place? There are a lot of misconceptions out there, so let’s break it down.

Myth 1: To induce vomiting

This idea isn’t so much a myth as it is a misunderstanding. There is no scientific evidence to support the notion that dogs eat grass on purpose because they want to throw up. The desire to eat grass is instinctive to dogs, and the main reason they eat it is because it’s there and it’s appealing to them. Dogs who are suffering from nausea sometimes have intense episodes of frantic licking or eating just about anything. Carpet, upholstery, and grass can be common targets of this nausea-triggered ingestion. Even though there is no evidence to support the notion that dogs eat grass to make themselves throw up, it’s important to consider that excessive, rapid licking at or consumption of anything, including grass, may indicate that your dog is experiencing nausea. A variety of insignificant and short-lived illnesses can cause nausea, but in some instances, feeling nauseated may be a symptom of a chronic illness. If your dog shows symptoms like frequent vomiting, decreased appetite, low energy, or weight loss, be sure to have him evaluated by a veterinarian, whether he is eating grass or not.

Myth 2: My dog has pica

If your dog seems to be a habitual eater of grass, you might wonder if he is suffering from the compulsive eating behavior known as pica. Although pica is a serious condition that should not be ignored, it is very rare. Pica causes compulsive ingestion of non-food items. Like many mental illnesses, pica can be so severe that it interferes with a dog’s ability to carry on with normal daily activities. Common targets for this obsession include rocks, sand, and articles of clothing like socks and underwear. If your dog is consuming huge amounts of grass (or any other non-food items), he may need to be assessed for pica, but eating grass in and of itself from time to time does not indicate a behavioral disorder. With that being said, don’t allow extreme behaviors to go unattended. If your pet ingests large volumes of indigestible material, this could create an intestinal blockage which is a surgical emergency.

Myth 3: Nutritional deficiency or parasites

Similarly, you can put to rest any ideas you might have that eating grass is the result of a nutritional deficiency or something your dog does to get rid of worms or other intestinal parasites. Simply put, that isn’t true.

While it’s reassuring to know that the vast majority of the time it’s totally normal for a dog to eat grass, you can talk to a veterinarian today to learn more about your dog’s grass eating habits if you are still concerned.

But there are blades of grass in my dog’s vomit (or poo), should I be concerned?

The misconception that dogs eat grass on purpose to make themselves throw up is largely due to the fact that dogs often regurgitate grass immediately after attempting to eat it. This is because dog teeth are not well suited to chewing up grass in the same way herbivore teeth are. When the dog tries to swallow the nearly intact blades of grass, it can lead to gagging, which in turn leads to foamy regurgitation. There is no evidence that dogs are trying to do this to themselves on purpose. It is just a sequence of events brought about by an animal eating without really giving it a lot of thought or consideration.

Similar reasoning explains why you may find intact blades of grass in your dog’s feces. Even though plant material is a potential source of food for your dog, his digestive tract isn’t equipped to efficiently digest it in the same way a herbivore stomach is. Given this, a lot of grass won’t get regurgitated and will pass through the dog’s GI tract undigested and show up again in the stool. The poor digestibility of grass means if your dog is experiencing digestive distress for any reason and also happens to eat some grass, you’re probably going to see some of that grass again. It’s an error in logic to attribute the cause of the GI distress to the grass itself.

If you are concerned about how much your dog is vomiting because he throws up on a regular basis -even if he seems otherwise fine- that should be pursued with a veterinarian regardless of whether your dog has ingested grass or not. Similarly, if your dog is experiencing frequent diarrhea, reduced appetite or weight loss, provide him with the medical care these symptoms warrant regardless of the presence of grass. In the vast majority of cases, eating grass does not cause illness.

How To Keep Your Dog From Eating Grass

The good news here is that since eating grass is usually a normal behavior, there’s no reason to try to stop your dog from doing it. As long as the grass isn’t treated with any toxic chemicals, it’s harmless. Even if long strands of grass gag your dog and make him throw up, that’s not harmful either. Like wolves, dogs have evolved to regurgitate easily and this type of occasional vomit doesn’t cause any injury to your dog.

If your dog falls into the less common category of eating grass because he’s nauseated as a result of some underlying illness, the best way to stop the behavior is to pursue diagnostic testing and treatment. Once the underlying condition is successfully managed and the nausea resolves, the grass-eating behavior will stop.

In the truly rare situation of a dog with pica, the only way to prevent the compulsion to ingest large amounts of non-food items is to prevent access to them. If the object of the dog’s obsession is grass, this could mean taking drastic steps like eliminating grass in part or all of the yard and training the dog to wear a basket muzzle around grass. Tactics like this are obviously not easy, but thankfully this is a rare disorder.

If your dog is otherwise healthy, it’s overwhelmingly likely that he eats grass for the same reason that people climb mountains. Dogs primarily eat grass because it’s there. Dogs are omnivores and grass can be appealing to them, so they eat it. This is especially true with the novelty of newly abundant, soft, green grass. Consuming any source of available food is instinctive for dogs and grass is no exception. So get out there with your furry friend and enjoy all of the sun and running around that summer has to offer, resting easy that a little bit of overzealous snacking isn’t going to do either of you any harm.