I shaved Dusty's buttocks (she is longhair and she looks like she's wearing "Britches" when she's totally long & furry!).
She can't groom back there very well due to her age. So I shave her down just back there. Not BALD; just a 'nice trim' to help her.
I am going to start shaving the problem areas of my eldest cat, Snickers. He also has been getting severe knots in his long fur, due to not being able to groom his long beautiful britches.
I don't think it's advisable to shave a cat bald... or a dog for that matter. I read someplace that dogs & cats NEED their fur to regulate heat and allow the sweat to have "some place to go" as it evaporates off their body. Sort of like humans. If you have no hair on your head, the sweat just runs off down into your eyes; if you have a full head of hair, it stays up in the hairshaft and then doesn't collect on the skin and/or run down all over the place.
Could just be a rumor, but I read you shouldn't shave long-haired pets 'totally bald'... just a trim here or there in problem areas.
(my pets are all indoor... even our doggie who only goes outside to diddle and play)