Took Zeus to the vet for his old man checkup on Saturday. He emerged with a confirmed 2 pound weight gain but a clean bill of health. The vet said everything looked good, that his eyes are getting a little cloudy (this I could see and was what prompted the visit) and a very erroneous guess that he's in his mid-teens. Our other vet guesses more like 8 or 9, a more reasonable number if you ask me. And more accurate, given his high energy level.