So far two of my cats have needed to have their teeth cleaned. Storm is 7 and had his teeth cleaned when he was 6 years old and Sunny is almost 3 and had his teeth cleaned this past April. I used to feed them both wet and dry food but now I only feed them dry food. I dropped them off in the morning and picked them up on my way home from work. They were still a bit groggy and weren't allowed to eat for a while. I was also told to keep them separated from the other cats until morning. They're supposed to stay quiet. Good luck. I think it's well worth it to have their teeth cleaned.