If you're a first-time dog owner who just brought home a new puppy, it's only a matter of time before you're wondering to yourself, "Why do dogs eat grass?"

We've pretty much all seen it—and some of us surely have likely seen a dog eating grass before vomiting (we'll get to that later). You're not alone. Your grass-eating dog is among friends because this canine practice is actually pretty common.

Keep reading to learn about the everyday reasons dogs eat grass, the possible health-related reasons they do it, and what you can do to stop the grass-eating behavior.

Why Is My Dog Eating Grass?

There are more than a few theories about why dogs eat grass, so it's difficult to determine the reasoning behind your dog's behavior. Especially because we can't ask them to tell us. Here are several potential reasons dogs eat grass:

They Like the Taste

Yep, some dogs think grass is tasty—especially when it's young, green, and tender. They may also enjoy the texture, which is delightfully different from the dry kibble or canned food they usually find in their bowls. So even though your dog gets the recommended amount of commercial or homemade food every day (plus treats!), he is biologically programmed to scavenge for food. And when he's out in the yard or walking with you around the neighborhood, millions of fragrant blades of grass beckon.

They're Bored

In some cases, a dog out in the backyard eats grass just to pass the time—especially if the squirrels aren't taunting him and his human is inside the house or at work. Or, he knows that eating grass will result in attention from his owner. Either way, Fido needs something to keep him busy, and snacking does the trick. Relatable, right?

It Might Fill a Nutritional Need

Veterinarians, scientists, and research librarians will tell you the act of eating odd, non-food items is technically known as pica—which may indicate a dog's diet is lacking certain vitamins, minerals, and fiber or chlorophyll (both of which aid in digestion). Some experts, such as the vets at VCA Hospitals, support the theory that it's because grass is a good source of fiber. Eating it helps a dog's bodily functions run smoothly. But there's no solid scientific evidence to prove this theory right or wrong, according to Psychology Today.

If grass-eating has you worried about your dog's diet, though, consult your vet about the most nutritious kind of dog food to feed your best pal.

It Could Help an Upset Stomach

Many experts believe dogs sometimes eat grass to induce vomiting that relieves their upset stomachs. It's an evolutionary thing, says Marty Becker, DVM, on his blog. Ancient wild dogs felt nauseous, which triggered an instinct to eat grass, which irritated their stomach linings, which led to the grass and the offending dietary choice being heaved up. So perhaps contemporary dogs come with the instinct to self-medicate with grass.

There's no solid scientific evidence to prove this theory one way or the other, however, and VCA Hospitals notes a tricky conundrum: Does a dog eat grass because he has an upset stomach and wants to vomit? Or does he develop an upset stomach after eating the grass?

Still, Deb Eldredge, DVM, who breeds Belgian Tervurens in New York, has found that her own dogs eat grass if they're stressed, have upset stomachs, or both. "They eat new spring grass like it's salad," she says. "But when they go for larger, wider, taller blades of grass, I know it's because they're going to vomit."

When To Be Concerned About Grass Eating

It's possible you landed on this article because you've seen your dog eating grass and vomiting yellow bile or something equally gross. Here's what to do: If your dog eats grass and vomits, but then seems fine, he's probably fine and just doing what dogs do. (After all, this species also eats poop, chews on couch cushions, and rolls in dead animals.) But if you have a dog eating grass and throwing up continuously, you should consult your vet. That's what you should do anytime you're seeing abnormal behavior in your dog.

"If your dog is constantly eating grass and throwing up, something's not right," Eldredge says. "If I were examining this dog, I'd want to get a really thorough history. Is your dog eating at all? Is he eating different food or different treats? Is he on medication that's upsetting his stomach? What is your dog throwing up? Is it bile and grass? Or just food? Does your dog have diarrhea? All of these things are important to find out."

Depending on the dog's history, Eldredge says she may take X-rays and conduct a blood chemistry panel to rule out liver and kidney problems. "The most common cause for a dog's nausea is a foreign body in the stomach," she notes. "Stomach ulcers and stomach cancer are less common causes."

If you have a teething puppy, he should be closely monitored, according to the American Kennel Club. He may be eating a lot of grass (as well as leaves and sticks) which could lead to a blockage.

Should I Let My Dog Eat Grass?

The short answer is no, you shouldn't let your pup eat the green stuff. Even if your dog is eating grass just because he loves the flavor, it's not guaranteed to be good for him.

Fresh, green grass may be tender and tasty, but unless it's your own lawn, you don't know if the blades have been sprayed with toxic chemicals that could make your pet sick. Nor can you tell if your dog is eating grass contaminated with intestinal parasites (such as hookworms) that come from droppings left behind by other dogs. Yuck!

Also, keep in mind that many house and garden plants are toxic to dogs, especially if eaten. Check out the ASPCA's Animal Poison Control Center for more info.

How Can I Stop My Dog from Eating Grass?

Stopping your dog from eating grass boils down to giving them something better to do.

Train Your Dog To Ignore Grass

If your dog keeps pulling you off the sidewalk to dine on grass, distract him when he's grazing by gently leading him in another direction. Or, try bringing high-value treats along when you take him on a walk. If he veers off course to nibble grass, give him a verbal cue such as "sit" or "drop" and reward him with a tasty treat when he complies.

Keep Your Dog Busy

Make sure he's able to entertain himself while he's alone outside. Give him a rugged chew toy to occupy his mind and his jaws. Exercise his body by investing in toys that don't need a pet parent involved, such as an interactive dog toy that dispenses treats or an electronic ball launcher.

Remember: It's not the grass itself that's bad for your dog, but the potential contamination from lawn chemicals and intestinal parasites. When your pup is distracted and away from temptation, you'll both be better for it.