I had an elderly kitty who used to throw up everything too until I switched her to a hairball formula. Even though it wasn't hairballs she was throwing up, it solved the problem for her immediately. Before that she threw up at least once a day. After switching her food she threw up maybe once a month or less. What worked for her was Hill's Science Diet Mature Adult Hairball Control Dry Cat Food. She loved it, and we were both so much happier without all the vomit. Hope this helps.