From Janet Tobiassen Crosby, DVM,
Your Guide to Veterinary Medicine.
FREE Newsletter. Sign Up Now!

Why do pets eat grass? It may be normal, some pets seem to like the taste of grass. They not be feeling well and eat grass to vomit. Or they may vomit after eating grass. There are many theories about pets and grass, but if your pet exhibits an odd appetite (eating non-food items regularly, called pica), or regular vomiting, please contact your vet as soon as possible.

A. This is an age-old question, one that I have never really seen a clear cut answer to. I think there are many possibilities: they like the taste of grass, they are hungry, they are not feeling well and eating something to see if that helps (kind of like humans do sometimes!). Some say that grass is part of a carnivore's diet -- when they feed on smaller prey they eat the entire animal, including grassy stomach contents.

Most dogs do best with 2 or more small feedings a day rather than one large feeding. Cats optimally would feed several small meals throughout the day. Ideally, for both dogs and cats, food should be available at all times. This aids in weight control (food is no longer a "big deal" and helps maintain digestive health. This is not possible in many situations and busy lifestyles, but if possible, my preferred way to feed pets.

A commercial diet or well-prepared home diet should not be lacking in essential nutrients. If they have an empty stomach, bile can reflux (flow back up in to the stomach from the intestine) and this is irritating. This can cause vomiting of clear, yellow fluid.

Any time that your pet experiences lack of appetite, eating odd items (pica), or vomiting, it is always best to check with your vet. Gastrointestinal blockages are emergencies. Changes in appetite or vomiting can also indicate internal disease (kidney failure, hyperthyroidism, etc.), toxin ingestion, or infectious disease, just to name a few possibilities. Always best to check things out with your vet.