Ask the Veterinarian/Dry patches and hair loss
My one year old red nose pitbull had what felt like dry mud or dirt sticking to her fur on her back and a small inch long rectangle shape chunk of fur came off her back along with what looks like a thin layer of skin but under it looked like black dots and now she is missing a patch of fur right where her collar is and without the chunk of fur it looks like if she got hurt because you see blood. That is the only patch that came off but theres other places on her back where you feel the clumps of fur what is this?, can it be cured without having to go to a vet?, and will her fur grow back?
From your description, this seems to be a superficial skin infection causing this. When there is a large pustule under the haircoat and it ruptures, it leaves a bald patch and loose skin. The hairs are usually dissolved by the bacterial enzymes, so they come off with the mass of goo. Keep these areas clean with an antibacterial soap and if they get bad, you may need to get some oral antibiotics. Once these heal, the fur usually grows back.