Why do dogs eat grass?

Amazingly nobody really knows for sure. Grass contains mostly water, but in addition also contains carbohydrates and has low quantities of other nutrients like protein, amino acids, vitamins etc...

After spending many hours searching the internet, and also asking this same question in a number of dog owner groups (online). I have compiled a short list of possible reasons for dogs eating grass. The list is in no specific order of probability.

1. “Dogs eat grass purely because they like the taste”. Certain grasses apparently taste sweet and Dogs do certainly seem to look for specific grasses. They do not just eat any old grass, and it always seems to be new shoots that they go for.

2. “Dogs eat grass as a nutritional supplement”. Personally I’m not convinced about this one as dogs that have a perfectly well balanced diet still eat grass.

3. “Dogs eat grass because they have an upset stomach”. Certainly if a dog eats grass without chewing much before swallowing, the dog will almost certainly vomit. If however the dog chews the grass well prior to swallowing, the dog will not vomit. So if a dog swallows something that makes him/her feel ill, then inducing vomiting would certainly seem like a good thing to do. Also if a dog has a mild upset stomach there would be some logic in them providing their stomach with some form of medicine which possibly well chewed grass might provide.

Personally I feel that it is probably a combination of both opinion 1 and opinion 2. Some dogs including mine could be considered grassers. My dogs eat grass every time they go out for a walk. Sometimes in copious amounts, so they obviously must like the taste. They can’t possibly have an upset stomach every day. I have also observed my dogs eating grass and swallowing without chewing which almost immediately induces vomiting, so I’m convinced that they also use grass as a medicine.