Ripley is 12 1/2 and has only had it done before his dental and once when he was extremely sick. My vet has never mentioned having it done annually but when I took my Dad's cat to their vet this year they wanted to do a whole "senior workup" on her and she's only 8. I didn't do it because it's dad's money and if my vet doesn't feel Ripley needs it then I'm going with his opinion over the other vet.