Why do dogs eat grass? This question has puzzled generations of dog owners. One minute they’re playing fetch, and the next, your lawn has become their salad bar. While this behavior is usually harmless, understanding the reasons behind it is key to keeping your dog healthy and happy.

We’ve gathered research and insights from experienced dog caregivers to summarize the main reasons—ranging from perfectly normal behaviors to signs that it might be time to see a vet.

Five Main Reasons Why Dogs Eat Grass

While there’s no single answer that applies to all dogs, research-backed evidence can help explain this common behavior. Based on veterinary insights and observed behavior patterns, here are the five most common reasons:

To Soothe an Upset Stomach

One of the most widespread beliefs is that dogs eat grass to induce vomiting and relieve stomach discomfort. While grass can sometimes trigger vomiting by irritating the throat and stomach lining, studies show that most dogs don’t actually vomit afterward. They may instinctively seek out grass as a form of self-soothing, as certain elements in grass can help lower stomach pH, aid digestion, or ease discomfort.

They’re Seeking Nutrients or Fiber

Dogs are omnivores and may sometimes use grass to supplement their diet with nutrients or fiber. If your dog’s diet is low in fiber, they may turn to grass to aid digestion and maintain healthy bowel movements.

Dogs with nutritional deficiencies or irregular eating habits may also instinctively seek certain plants to supplement their food. Ensuring your dog has a balanced, fiber-rich diet can help reduce this behavior. For example, offering fiber-rich fruits or vegetables can be beneficial.

They’re Feeling Bored

Dogs left alone in the yard for long periods may start eating grass out of boredom. It’s an activity, a way to pass the time. If this is the case, you might notice the behavior decreases when you provide more exercise, interactive toys, and quality playtime.

They Enjoy the Taste of Grass

Fresh, dew-covered grass can be appealing to dogs. Chewing and tearing grass leaves can be satisfying in itself. For these dogs, grass is simply a tasty, readily available snack. It’s important to make sure the grass they eat is free from pesticides, fertilizers, or harmful chemicals.

It’s an Instinctive Behavior

This behavior may be an inherited trait from their wild ancestors. While most domestic dogs now eat commercially produced dog food, wild canines often consume the entire body of their prey, including the grass and plants in the prey’s stomach. Eating grass may be a deeply rooted instinct, a natural behavior that has persisted through domestication.

Do Dogs Eat Grass to Vomit?

This is an important point to clarify. Although it’s a common belief, most veterinarians agree that dogs usually eat grass for reasons other than inducing vomiting. In fact, one study found that fewer than 10% of dogs showed signs of illness before eating grass, and only about 25% vomited afterward.

Therefore, while vomiting can sometimes occur, it’s rarely the intended goal. If your dog eats grass and then throws up, it’s more likely because the grass irritated their stomach during digestion rather than an intentional act to feel better.

When Should You Be Concerned?

While occasionally eating grass is usually nothing to worry about, it’s not always a harmless habit. How can you tell the difference between quirky behavior and a sign your dog needs help?

You should pay closer attention and consider contacting your vet if your dog shows any of the following signs while eating grass:

1. Frequent or severe vomiting after eating grass.

2. Signs of pain or illness, such as drooling, lethargy, loss of appetite, or changes in bowel habits.

3. The dog may eat grass frantically or compulsively, seemingly unable to stop.

4. Suddenly developing this behavior when they’ve never shown interest before.

5. Eating chemically treated grass—this is a serious risk, as lawn pesticides, herbicides, and fertilizers can be highly toxic to dogs.

What Should You Do if Your Dog Eats Grass?

If your dog occasionally eats grass and shows no other symptoms, there’s usually no need to worry. However, you can take a few proactive steps:

1. Monitor your dog’s diet: Make sure they’re getting balanced nutrition and enough dietary fiber.

2. Provide plenty of exercise: Offer toys, physical activity, and social interaction to reduce boredom-related grass eating.

3. Check the environment: Ensure your dog isn’t eating grass treated with chemicals or pesticides.

4. Observe behavior patterns: Pay attention to whether grass eating is linked to illness or stress so you can intervene early.

Conclusion

While the exact reasons dogs eat grass may vary, the general consensus is that occasional grass eating is normal behavior. It can result from a combination of instinct, diet, and boredom.

There’s no need to worry about a dog that occasionally eats grass. Instead, focus on providing a stimulating environment and a balanced diet. Only if the behavior becomes compulsive or is accompanied by vomiting or signs of illness should it be a concern. When in doubt, it’s best to consult your veterinarian to ensure your dog stays healthy.