Alright, so here's some background information, maybe it's relevant. We live in a compact three bedroom apartment in Las Vegas. I originally had two cats, but then my sister moved back in and brought her two cats. My two cats were bought as kittens at pet shops and only have whatever basic shots were given to them by the pet shop. I can't say anything for my sisters cats, she got them from friends. The problem described below definitely started after she brought her cats in, but I don't know if they had it when they came in or it developed recently along with my cats, since they're mean and I don't pay much attention to them. They've been with our cats for about 6 months now.
Here's the problem. I noticed that all four of our cats have some weird developments on their chin. They have patches of hair loss or thinning around their chin area, usually with a scab or hardened spot of sorts (which has produced blood upon cleaning) and lots of little black dots around the area. One of them has it really bad with very noticeable patches of hair gone and dark black stuff and dots in the missing patches. The fact that it's happening to all of my cats and only on their chins probably rules out a lot of things, does anyone know what it could be?
Here's the problem. I noticed that all four of our cats have some weird developments on their chin. They have patches of hair loss or thinning around their chin area, usually with a scab or hardened spot of sorts (which has produced blood upon cleaning) and lots of little black dots around the area. One of them has it really bad with very noticeable patches of hair gone and dark black stuff and dots in the missing patches. The fact that it's happening to all of my cats and only on their chins probably rules out a lot of things, does anyone know what it could be?