[header] How to diagnose chronic vomiting in cats [title] Be aware that if your cat eats grass a lot, she may be a' happy' vomiter. [step] A key sign of a happy vomiter is a cat that is otherwise well but has a tendency to eat grass and make herself sick. This is a predictable chain of events that you can generally observe on more than one occasion. 
Some cats make themselves sick once every two or three days, while others only make themselves sick once a week. Once they have induced vomiting they are content to wander off and perhaps even look for a snack.