Do you ever hold the end of your cats tail for them, so that they can clean it? I do this & only became conscious of this fact tonight.
It first started with my late cat, who always had a disgustingly dirty end of tail. So much so, that I once took him to the vet with said tail, cos I thought it was diseased, only to have the vet tell me that it wasn't a disease but a load of dirt and that he was a very dirty boy. He actually wasn't known for his cleanliness and very rarely washed. He was filthy dirty the day he turned up on my doorstep as a stray and I spent weeks combing the dust out of him. That was 20 years ago now. Happy days.