Don't you know that dogs are eating grass so that they could treat their upset stomach? They would regurgitate that foods that is making them ill after they have eaten blades of grass. I'm amazed because dogs also know how to use herbs to cure their own sickness.
It is kind of funny that they have that built in instinct. Cats do that too. The only problem I have with it is when they eat grass outside and then puke in the house!
It's not just dogs, cats do it too. I was afraid when my cat started to chew on grass when he went outside so I asked the vet and they said it was fine. It is great that they know how to take care of themselves.
In PetSmart they actually sell little kits so you can grow grass indoors for cats. I've never bought one, but I think they're like little window boxes and they come with the seeds and everything you need.
Interesting. Dogs and most other animals usually develop instincts for curing themselves and maintaining their health. They even do fasting (stop or reduce eating) when they are sick.