Welcome to PT!!

This "coffee grind" sounds familiar to me, my Katz's chin looked that for years; in the end, it was all bloody and bruised. I was told it could be feline acne, but I'm not quite sure. I was also told this easily occurs when cats eat from plastic bowls.

Pulling out the fur could very well be stress-related! But I think a vet should see her, to find out if there's an underlying medical condition, like food allergies etc.

Hope your kitties will soon feel better!

Kirsten