Vinny's never had senior blood work. My vet has never told me that he was supposed to have anything special done as he aged. In fact, at my last visit in April, when I suggested starting Vinny on senior food, he shook his head and told me he doesn't need it.
Right now they're eating a mix of Science Diet Indoor and Authority Indoor, as I'm in the process of switching them to Authority. I also feed them Meow Mix wet cups once or twice a week. I'm on a very tight budget with everything in life right now so feeding them more expensive food or more wet food would be a bit difficult.
I'm not concerned with keeping Vinny "trim" as he and my Sherman are both long and lean. Vinny still plays, runs, jumps, scratches, and is friendly. He is getting a bit gray around his eyes and ears, but that's the only sign of age. He also had a minor urinary tract "problem" in April (the emergency vet said she "hesitated to call it an infection because there wasn't blood or crystals in his urine, and he wasn't blocked" but he was visiting the litter box and nothing was happening one day. He was on clavamox for 48 hours and it never happened again) but other than that he hasn't had health problems.