Herself opted to give him a bath. Although he shook his head a few times when the water was too close to his face, he made no effort to climb out of the sink or to even escape Herself's hands. In fact, he tweeted and chirruped rather amiably, and sat comfortably on the towel while the warm water washed over him. Since guinea pigs can catch cold quite easily, Herself wrapped him up carefully in a towel and had Offspring the Third hold him while she tidied up his habitat. She opted to put a towel/blanket under his house rather than solely wood chips; if he is a tad bonier than he used to be, a softer bed will be more comfortable to him.
He waddled around his habitat later in the evening, and consumed a pile of lettuce with enthusiasm. He followed his lettuce with some hay and a few pellets, too. He's always been quite the eater -- his appetite is undimmed despite his abundance of years.
We do not know precisely how old Moose is. He arrived in our home six years ago this forthcoming August -- an adoption through Craigslist of him and his companion, James, as their human girl was going away to attend college -- and they both seemed to be full grown at that time. Our best guess is that he is between 6.5-7 years old, and probably closer to 7. Depending upon the source of information, the average lifespan of a guinea pig is allegedly between 4 and 8 years (or 5 and 7, or 4 and 5). At any rate and by most scales, though, venerable cavy is Pretty Darn Old.
Age is inevitable, for all of us. It's hard knowing that Moose will likely cross the bridge sooner rather than later. We'll do our best to ensure his twilight months are as comfortable and vegetable-laden as possible.