A family that loves animals and owns a lot of them will by necessity have to deal with this kind of pain more often than some other families might. On the other hand, they also get the extra happiness that makes it all worthwhile. A loss of a pet is a loss of a family member, and there's no getting around that.

Pippin was a rat my daughter brought home to "save from a snake." In his later life, he had some kind of a stroke, probably from sheer overeating (made Templeton look anorexic), and had to be cared for and sometimes even hand-fed. There were trips to the emergency vet with my anxious daughter, and nights in a special oxygen box. I probably spent almost a thousand dollars over time on a rat I could have bought for two bucks--and I'd do it again. He died while we were out on afternoon, his head, somewhat appropriately, in his food dish. He's buried outside, under a statue that looks like this:

Now, we have Basil, a white mouse who also was "saved from a snake." He eats good, nutritious low-fat mouse pellets whether he likes it or not.

If it's any consolation, it's entirely possible that the dryer incident and your cat's health problems were coincidental, and not caused by the dryer, other than perhaps making an already existing condition more obvious.

In most of the "cat in a dryer" things I've read about, the cat suffered no permanent ill effects.