cat has what appears to be the equivalent of diaper rash...again

My older cat, about every 6-12 months for the past several years,gets what appears to be the equivalent of diaper rash in babies.

Usually a bath and a trip to the vet where antibiotics are prescribed, and the problem goes away.

It is going to be about 4 days before the local vet can see my cat

I have never sought out a second opinion on this re-occuring problem and have had doubts the antibiotics do anything for the problem

Any thoughts?

My thoughts are, if you have your doubts that the antibiotics are working, then why not try doing the bath only, and see if that does the trick, since you can't get to the Vet for a few days anyway .  If that works, then you'll know.

BTW, I don't really understand what it is you're seeing that equates to diaper rash.  Doesn't your cat have lots of fur on his little tushie?  Where exactly are you seeing this?  (sorry, I've never been around any human babies )  Also, what has the Vet said it was, when he's had this issue in the past?  Does it have a name? 

I can't help wondering if this might have anything to do with anal sack disease and/or the results of chronically loose stools. 

So, I'd just like to ask, how are kitty's stools? 

(Normally antibiotics are used for anal sack disease.) 

Sorry about the spelling error.  I meant anal sac disease.