Why do dogs eat grass? There doesn't seem to be a clear and definite answer for this question. But just about all dogs do it for one reason or another; whether as an additional vitamin sourse or to empty the contents of their stomach. As I was prepairing my dogs dinner tonight Luke decided to go outside and eat grass. Knowing him like I do; I knew he was going to be sick because he was probably hungry. Could I stop it? Yep. I can usually stop the whole process if I work fast enough, if it is due to hunger. If Luke is not feeling well then he just needs to get rid of whatever is bothering him.
Dogs eat grass and not always to make themselves vomit. Dogs often eat grass because it tastes good, this I know from many years of experience with my own guys. My dogs love spring grass and when they are set loose in the canyon or field after a couple of good rain showers; they resemble cows. They will and often eat grass at all times of the year but the new baby grass is obviously the best.
The only place my dogs are allowed to eat grass is where I know there are no chemicals like in natural fields, canyons or my own yard. In fact when we moved into this house I assumed the grass was treated; so I went out and bought my dogs their own grass and planted a pot of it on the patio. I trained them all that this was their grass to eat and they all graze from it. We don't seem to have grass in our yard that they enjoy eating, it is a much tougher, harsh type.
When a dog eats alot of grass at an increased rate, not the grazing type of consumption; the chowing down kind of eating grass; there is a good chance that they need to clean their stomach. Don't stop your dog if they feel the need to vomit; just keep them outdoors until they are done. Oh, and a rule of thumb is that they always vomit at least two times in a row. All dogs are different but most dogs react to foreign substances in their stomach by vomiting. So the fast consumption of alot of harsh grass works well. I know everytime Luke would eat a bit of his frisbee before returning it to me; he was sure to vomit the brightly colored plastic up shortly.
Grass is a very natural source of vitamins, minerals, enzympes and amino acids for dogs. Chlorophyll can be found in grass, which was used for many ailments before the introduction of antibiotics. Dogs are very smart; they've been eating grass for years and years; we humans are just figuring out the benefits of grass consumption.