If Barry isn't having any problems, and isn't senior, an exam may be all you need. If senior, my vet usually does a blood panel once a year. If senior and problems (like insulin-dependent diabetes) or CRF, my vet usually does a blood panel every six months (I sometimes stretch it to 8 months). Last time, my very senior Ennis (17YO) was in for a dental (under anesthesia), he got the full blood panel, chest X-ray, and heart ultrasound. They didn't do a urinalysis because Ennis had none to give. He hasn't had pee in there at the vet's for the last 3 years!
Usually, the vet will talk with you about what s/he thinks are the appropriate testings for age and condition.
