Why Does My Dog Eat Grass? 4 Possible Reasons

Why does a dog eat grass? Ask any pet owner if her dog occasionally eats grass. The answer is probably 99 percent “Yes!” Most of us, however, have only guesses as to why this common behavior happens.

I have had two dogs who as far as I can see eat grass only when they have an upset stomach, and eat until it helps them vomit up whatever is bothering them. Other pet owner friends of mine have dogs who chew grass more frequently, and never vomit, or chew grass and even soil on occasion for no apparent reason.

Why Does My Dog Eat Grass?

There are a variety of reasons why your dog is eating grass, including improving digestion, craving some nutritional need, treating intestinal worms or just because it tastes good.


So what do the experts say? Here are the results of my search:

1. Upset Stomach

Do dogs eat grass to make themselves vomit, or do they vomit because they are eating grass? Do dogs “know” enough to eat the green stuff when their stomachs are upset? According to some experts, fewer than 10 percent of dogs who eat grass appear to be sick, and fewer than 25 percent vomit.

2. Pica

Pica is a condition that causes animals and people to crave things that contain certain minerals and nutrients that they are deficient in. Sometimes dogs will eat clods of soil as well.

Perhaps it is an instinctive craving that they carry over from the wild ancestors.

If your dog is eating grass and soil  — or other weird things like paint chips or licking things that look suspicious — it would be a good idea to have your veterinarian check for deficiencies. Pica is also considered to be caused by boredom, and most vets consider it normal dog behavior, according to MedicineNet.com.

If you suspect pica, try to get your dog more exercise! I’m talking playtime with Frisbees or ball chasing and longer walks — and get him a good sturdy chew thing for when you are away from home.

3. Territorial Invasion

Some research suggests that dogs may eat grass that has been marked to sniff and taste who has been in their territory. We all know how much more sensitive the dog’s nose is, and how important those sniff postings are on their daily walks.

4. Taste

Just as we enjoy a good salad, maybe dogs actually crave the taste of grass. Grazing on those tender greens might supply some enjoyable variety to a canine’s daily meals.

If your pet seems to be one of these “connoisseurs,” plant an area in your yard or grow some of these garden greens in a container. Be watchful when you take the dog to public places, and even neighbors’ lawns.

Weather Prediction?

Believe it or not, there is an old farmer’s saying I will paraphrase thusly: “If you see your dog eat grass today, it’s time to hook up the horse and mow the hay.”

The meaning of this saying is that grass hay needs to be cut two or three days for it to dry before it can be baled, and a dog eating grass somehow meant it would be dry for a few days. Oh well, I loved the Farmer’s Almanac as a kid, mostly for the illustrations and the quaint stories, but this seems a bit farfetched.

There is a lot of use of pesticides and poisons by gardeners in parks and on lawns. My neighbor and I have an ongoing discussion about how to keep her yard neat without Roundup being her “go to” solution. She seems to be trying!

Some plants are toxic to dogs. Check the ASPCA’s Animal Poison Control Center website, which maintains a list of toxic and non-toxic plants.

Photo: Adam Foster/Flickr

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  • Janie

    I think dogs eat grass for two main reasons. First, to purge; second, because they want to. What I mean is that grass has a lot of phytonutrients, including chlorophyll, and roughage. Dogs know when they need either of these.