Why Does My Dog Eat Grass?

Have you ever taken your dog out for a potty break and turned your back, only to discover them chomping on a large mouthful of grass? While you might panic and think about the vomit you’ll be cleaning off the carpet, later on, this behavior does not always cause for alarm. But why do they do it and how do you know when it is actually a problem?

Some dog owners and veterinarians assume that grass eating is a form of pica, or eating strange items, sometimes caused by a diet deficiency. Many diet deficiencies are rooted in missing vitamins, nutrients, or minerals that are absent from daily intake. For example, it could be your dog’s way of getting more fiber, which helps them pass gas and stools, and also assists other bodily functions.

But if a dog’s diet is complete and balanced, eating grass may not be related to a deficiency at all—it might actually be instinct. Dogs’ digestive systems, dietary needs, and cravings have evolved to fit the lifestyle of domesticated dogs. While canines in the wild weren’t getting their primary source of nutrients from grass, eating an entire animal provided an optimal diet, especially if the animal’s diet consisted of various plants. Dogs are omnivores and naturally crave the act of eating grass as part of their genetic makeup, dating back to when they hunted their own prey.

Of course, they might also just enjoy the taste and texture of the grass in their mouths, especially when new grass is emerging for the first time during spring.

Is Eating Grass Bad For Dogs?

The consumption of grass can be a sign that your dog is attempting to relieve an upset stomach and some pups do vomit soon after eating it. That said, fewer than 25 percent of dogs actually vomit from eating grass, and only 10 percent show signs of illness prior to eating grass, meaning most are not likely eating it because they’re sick. But while it’s not typically harmful to dogs, eating grass can cause intestinal parasites that are easily picked up from animal droppings and stools. It’s also important to note that the herbicides and pesticides sprayed on your lawn can be harmful to your pup.

When Should You Take Action?

If you notice them eating grass more frequently or excessively, be alert of potential underlying illnesses that your dog is attempting to self-treat. Also look for vomiting, diarrhea, weight loss, decrease in appetite, blood in stool, lethargy, or lip licking.

Always monitor your dog when there are house plants nearby, as certain varieties can cause toxicity if they’re chewed or ingested. While chewing on the lawn is a common behavioral action in many canines, you can train your dog out of the behavior to help provide peace of mind.

It’s always best to consult with your vet if you think your dog has chewed on a toxic house plant or possibly ingested too much grass or small amounts of chemicals. The vet will be able to perform assessments like fecal samples, blood tests, or even physical exams to determine underlying conditions. If your dog doesn’t exhibit any symptoms, but you feel that they may have ingested too much grass, keep them hydrated and allow time for potty breaks. Have your dog fast 8-12 hours before introducing food slowly. After 12 hours if your dog continues to show signs, check in with your veterinarian.

Keep an eye out for these grasses.

Foxtails — small, dry seeds produced by invasive, grass-type weeds — are prevalent in many lawns and pose a serious risk to dogs. If you have foxtails in your yard, be diligent about removing them (dig or pull them up, or soak them with vinegar at ground level), and watch your dog closely when in the yard.

One caveat when it comes to grass consumption: Long, rigid grasses with sharp edges have been known to cause throat abrasions. The esophagus is sensitive and in some cases, dogs who eat this type of grass can experience a serious medical issue. If your dog is coughing or showing signs of irritation after eating grass, it’s best to contact your veterinarian immediately.

And, as always, if you have any concerns whatsoever, especially if your dog’s grass-eating seems excessive, persists for long periods of time, or if they aren’t eating normally, it’s best to have them assessed by your veterinarian.