About a year and a half ago, our cat Diana was clearly dying. She abruptly lost a lot of weight, looked absolutely miserable, and gave up interacting with her environment. Naturally, we were very upset, and rushed her to the vet, expecting the worst. It didn't seem like diabetes (we've maintained two diabetic cats before); it seemed to resemble more closely the kidney failure that had claimed her sister Sasha.
However, her prognosis turned out not to be quite as dire as Sasha's--according to our vet, elderly cats are prone to hyperthyroidism, and if you can get it under control (which she later confessed she didn't think we were going to, as badly off as Diana was, but happily, we did), they can actually be maintained with decent quality of life. Diana currently seems to be doing fairly well on Methimazole (applied, interestingly, as a topical cream to the inside of her ear; apparently not an option available to human thyroid patients) since she was diagnosed. Radiation remains an option, but up until now, she has been reasonably well-maintained on the topical cream, so we haven't opted for the additional absence from home, and constraints on mixing in person and in the litter box with our other cats that radiation would require.
Lately, though, Diana is slowing down more, and I've noticed a dynamic developing between us that has occurred with our other elderly animals as well--Momo and Shaman the cats; and Dorothy, Dorothy, and Dorothy the hamsters, among others.
It goes like this--the animal, who is older and slowing down, starts sleeping more and more soundly, getting much more deeply relaxed, and--not to put a fine point on it--looking like it might be lying there dead, since it's often very hard to see its breathing. I come along, see it lying there, watch it for a while trying to see it breathe, get more and more concerned as I can't be sure, and finally, I can't resist--I have to touch it to make sure it's still alive.
The animal, who's been sleeping very soundly, jerks awake in terror at this unexpected stimulus--and that burst of adrenaline just can't be good for it, I know it. So in trying to reassure myself that the animal is still alive, I hope I'm not actually shortening its life. :P
There's got to be a better way for both of us than this cycle.