By Jennifer Copley (Last Updated 5 September 2010)
Wild hunting cats and dogs consume some greenery when they eat the stomach contents of their prey, and non-hunting pets may need to get this vegetable matter by other means. Grass eating is a natural behaviour. Even big cats such as cougars eat grass.
Reasons Why Dogs and Cats Eat Grass and Other Plants
It’s not known for sure why cats and dogs eat grass and other plants, but the most plausible theories are that grass is needed as:
- Roughage (for its laxative effects)
- An emetic (to help with vomiting up indigestible matter)
- A vitamin supplement
It’s possible that all three of these requirements play a role.
When cats and dogs consume prey whole in the wild, they often consume bones, fur, feathers, and other indigestible parts. Cats and dogs also swallow their own fur during grooming, and if hairballs begin to form, they must be either vomited up or moved down through the digestive tract efficiently so that they don’t form a digestive obstruction. Grass may aid both in inducing vomiting and providing laxative fiber that moves hairballs and other indigestible matter through the digestive system, preventing obstruction and constipation.
Some biologists have suggested that dogs and cats eat grass to obtain small amounts of critical nutrients, particularly folic acid. Folic acid is a vitamin that aids in hemoglobin production and other functions. If they do not get sufficient folic acid from their diets, animals can become anemic. Cats and dogs may eat grass to obtain trace amounts of this vitamin, and perhaps other nutrients as well.
Grass Eating is a Natural Behaviour in Cats and Dogs
Most cats and dogs will snack on grass if given the opportunity, and grass-eating is only a problem if the grass is coated in toxic pesticides (those with gardens should use non-toxic pest control to avoid poisoning free-roaming pets). Dogs can usually get their fill of grass while out on walks, but an indoor cat doesn’t have this opportunity, so she should be provided with a pot of cat grass.
- Bush, B. (1984). The Cat Care Question and Answer Book. Boston, NY: Bookthrift Co.
- Busch, R. (2004). The Cougar Almanac. The Lyons Press.
- PetMD.com. (2010). “Why Do Cats Eat Grass?”
- Nelsen, K., Dr. (4/2/2010). “Sago Palms are Poisonous to Animals.” Dr. Nelson’s Veterinary Blog.
- Tobiassen Crosby, J., DVM. (n.d.). ” Frequently Asked Question: Why Does My Dog (or Cat) Eat Grass?” About.com.