I have a 18 month old brother & sister. The boy is very stinky, it's his rear end that smells to the extent that if he sits on my lap I have to change my clothes. It isn't all the time but fairly regular.
I took him to the vet who did an anal check (very unhappy cat!) and couldn't find a cause and it's not his glands. .he wasn't smelly when he was at the appointment though.
Both are neutered and his sister is absolutely fine. They are on wet & dry food and he loves his food so eats very well.
I've had cats since my childhood and never had this before (Phobe's smelly cat song plays in my head)
Any ideas?