There’s a lot of debate about why dogs eat grass. Some dogs seem to act like mini lawnmowers, eating grass at every opportunity. Others dogs eat grass only occasionally, subsequently throwing it up.

So do dogs eat grass to throw up? This is a debatable issue. This wisegeek author has observed her dog fling himself at the door to get out to grass and eat a few mouthfuls, usually when his stomach is upset. He also appears to do it when he has something stuck in his throat. The end goal of the dog seems to be to throw up.

There actually appears to be two types of grass eating behavior in dogs. Some dogs take a few nibbles, while others eat quickly, barely chewing the grass. Unchewed grass often translates to near instant vomiting. Dogs that are careful grazers, on the other hand, may not get sick from grass.

The latter case suggests that some dogs eat grass because they enjoy it. Most dogs don’t need it to supplement their diets, but because dog diets are primarily made up of herbivores, that grassy taste may be reminiscent of the cattle or lamb product they had for dinner. Some dogs also enjoy green vegetables like broccoli.

If your dogs eat grass on a regular basis, this could suggest dietary imbalance, though many vets might dismiss it. You may want to consider giving the dogs some green vegetables if they appear to want “something green.” Cooking the vegetables first may make them more digestible, resulting in less vomiting.

It’s also important to be careful when your dogs eat grass regularly. Grass from manicured lawns can contain fertilizers and pesticides, which can be toxic to dogs. Instead of allowing “grazing” behavior on lawns, consider providing some doggy grass at home that is not treated with chemicals. Also, if your dogs eat grass all the time, don’t walk them on lawns that have been recently treated with chemicals. Most of these chemicals will break down in a few days, but during the first day or two after treatment, grass-eating behavior could translate to more than tummy upset.

If your dogs eat grass as a new behavior, and are exhibiting frequent vomiting, it’s also important to check with a vet. A dog that suddenly begins to have a taste for grass may be trying to compensate for gastrointestinal problems. This could signify viral or bacterial infections and might require veterinary treatment. On the other hand, when dogs eat grass only occasionally, you can chalk this up to normal canine behavior. A mouthful of grass or two may mean cleaning up some nasty dog messes, but it is unlikely to signify poor dietary health or illness.