Why Do Dogs and Cats Eat Grass?

Submitted by:  Dr. Sabrina Walters

Many people are puzzled and sometimes concerned when they see their dogs or cats eating grass. Why do they this, and is it harmful?

First, the dogs. There are a few theories as to why dogs eat grass. One is that it may be an evolutionary or instinctual behavior. Dogs are actually omnivores meaning they eat both meat and vegetable material. Wild dogs forage for fruits, vegetables and other plants to supplement their diets. For our domestic dogs, grass is often the most readily available plant for them to munch. Second, dogs may eat grass if they have an upset stomach. Eating grass causes irritation to the stomach and will often cause the dog to vomit. Occasionally, a poor diet or feeding an inadequate amount of food may cause a dog to eat grass, but this is uncommon. Finally, some dogs just seem to enjoy eating grass. As long as the grass is not treated with any chemicals or pesticides, it is very common and safe for dogs to ingest grass.

Now, on to the cats. Cats eat grass for many of the same reasons dogs do. Cats are obligate carnivores meaning their diet consists solely of meat. Why then would a cat want to eat grass if he is a carnivore? Cats that hunt and eat prey animals may ingest grass to purge indigestible parts like feathers, fur and bones. Eating grass also provides roughage or fiber and can act as a natural laxative helping hair move through the digestive tract and promoting regular bowel movements. Grass also contains folic acid so cats may seek grass as a supplement to their diets. And, just like dogs, some cats just seem to enjoy sampling a few blades of grass.

So, occasional ingestion of non-treated grass is fine and should not cause any worries or harm. But if your cat or dog seems to be eating excessive amounts of grass or is frequently vomiting, visit your veterinarian to make sure he or she does not have a more serious medical problem. Remember, while grass is okay, some cats (and dogs) may also try to chew on or eat other types of plants, some of which can be toxic. Make sure your furry friends do not have access to toxic plants.