At least some cats condescend to wash their anuses out first. My Bombay is uber clean but my Angora gets poop stuck in hair and I have to shave his butt and the little pouch thingie his pee wee is in. He is 15 with arthritis and diabetes so that gives him an excuse although the first time this happened and I shaved it he enjoyed the shaving and now it happens regularly which is no coincidence. Probably sneaks out and tells all the cats in the area that he has me shaving his butt hole for him. Got an electric pet shaver. Grooming isn't as easy so we shave some knots he gets on his backend where his arthritis is. He seems to enjoy things most cats hate including blood sugar ear prick tests which can even piss off dogs. Vet sucked urine from his bladder with a syringe for a sample and he didn't mind. My pain tolerance is high but I can't say I'd be very likely to do that
