Is It Normal For Dogs To Eat Grass?

My two Standard Poodles, Zephyr and Raja, are as different as night and day when it comes to eating grass. Zephyr would make a beeline towards any grass stems that he saw and start munching on them right away. After a few minutes of chomping on grass, he would have the tell-tale signs of what comes next: his stomach would start to heave, he would start to make gulping noises, and soon all of the grass would come back up, accompanied by a frothy yellow liquid from his stomach. Zephyr was so enthusiastic about eating grass that one time he ate some kind of grass leaves that had sharp edges, damaging his throat. He went around coughing for about three weeks after that, but the experience did not deter him from wanting to eat as much grass as he possibly could. Raja, on the other hand, could take it or leave it. When Zephyr was eating his fill of grass, Raja would take a few mouthfuls to be polite, but otherwise he was not interested. And he never vomited what he ate.

As I was thinking about this difference in behavior, I came across an article that was published last year about plant eating by dogs (Sueda, KLC et al. 2008. Characterisation of plant eating in dogs. Applied Animal Behaviour Science 111: 120-132).

This article reported the results of a couple of surveys of dog owners whose dogs had eaten grass or other plants. One survey was given out to people who brought their dogs to the outpatient clinic at the University of California, Davis, Veterinary Medical Teaching Hospital. To guard against any biases in reporting, the owners were not told that the survey was designed to assess plant eating by dogs. Instead, they were told that the survey was to provide information about the general eating behavior of pet dogs, and there were questions about the diet of the dogs, whether the dogs ate non-food items, and also whether they ate plants. Of the 47 dog owners whose responses were analyzed, 79 percent reported that their dogs ate plants, and 95 percent of those dogs primarily ate grass.

The authors then did an internet survey of plant eating by dogs. They analyzed 1571 responses. Most people (98 percent) reported that their dogs ate grass at least some of the time. Other plant material included berries, sticks and leaves. Most of the owners (92 percent) said that their dogs were not ill before eating plants, and relatively few (22 percent) said that their dogs vomited within one hour of eating the grass. Those dogs who were fed a commercial diet were more likely to vomit after eating grass than dogs fed a home-cooked or raw-food diet.

When the authors considered the results by age and breed of dogs, some interesting trends showed up. Older dogs (9 or more years old) tended to eat grass more often than younger dogs (less than one year old), although younger dogs tended to eat more different kinds of plants overall than older dogs. Also, older dogs tended to vomit more after eating grass than younger dogs. Among the different breeds, hounds and toy breeds tended to vomit more than other breeds.

Ultimately, the authors of the study could not come to any conclusions as to why dogs eat plants, particularly grass. Here I should say that some plants are very toxic to dogs, particularly some houseplants, and dogs definitely should not eat those plants. But as to why dogs eat grass, the authors were left only with some speculations. One idea was that the grass somehow helps remove internal parasites from the stomach, and the authors suggest that this might explain why older dogs, who might be expected to have accumulated more intestinal parasites, eat more grass. Another idea was that the dogs are somehow extracting medicinal qualities from the plants that are beneficial to their nutrition.

To get back to Zephyr and Raja, this still leaves me puzzled. Zephyr always had problems with his stomach being upset, and perhaps this was a way of clearing out a painful accumulation of stomach acids. Raja, on the other hand, has a cast-iron stomach. Maybe this is the reason, or maybe it is something else. At least I know that my dogs have good company – most of the other dogs in the world probably eat grass too.

--Con Slobodchikoff

Comments

[Domain Names]

I know cows eat grass, and dogs it it when their owner doesn't feed them.

[Sara Wiegmann]

My dogs are 9 month old lab-retriever mixes, brother and sister, and they eat grass, and ANY kind of wood they can find. They LOVE the clumps of grass left by the lawn mower, if I don't get them raked, they eat them all. They chew on tree branches, both live and dead, my deck, my daughter's swingset, and dig fir tree roots! What can I do to stop the destruction?

[Ares]

My dog eats grass all the time. I have heard many different things, from 'It's good for their digestive system' to 'She's gonna DIE!'. She never eats too much, so I have to believe that she doesn't eat it for food, but for some kind of self-medication!?!

[Colleen Falconer, CPDT]

This is a very timely topic for me - thanks so much for blogging about it! I have basenjis and both of them are major grass eaters. Now that spring has sprung here in MN, both of them are out in force, gorging on the new blades. I've notice both dogs have a preference for "quack grass" (the thick bladed grasses) and seek that out, avoiding the shorter, lighter, thinner grasses. Mina, my female, frequently awakes and immediately appears distressed; when I let her outside, she makes a beeline for the thick grass, chomps some down and immediately vomits it back up. She's always had digestive issues and it appears that the grass-eating helps alleviate that temporarily. I've tried a variety of things to help with tummy issues, but the only thing that's seemed to help is to put her on cooked or raw food, which I unfortunately don't offer consistently, due to cost and time constraints.
cheers,
Colleen Falconer, CPDT CTC

[Randall Johnson]

My 10-year-old English cocker spaniel, Goldie,shares something in common with Zephyr in that she often suffers from stomach upsets, eats grass, and later vomits the grass, along with a greenish-yellow liquid. Four-year-old Suzie, a minpin, often eats grass and shows signs of seeking it out, but without vomiting afterwards. In her case, grass-eating may be a case of supplementing her diet. As for Aladar, a Dalmatian mix I adopted off the street a little more than a year again,I've not yet seen him eating grass or any other type of plants. (However, as a former street dog, he still shows occasional interest in the contents of unprotected garbage bags.) Although we think of dogs as being carnivorous, they are technically omnivorous because grasses--and other plants-are also a part of their diet, although to a lesser extent.