Hi bella , that tail looks really nasty. Whatever the cause , in order to let it heal she needs to stop chewing on it. I'd get her one of those lamp-shade / Elizabethan collars so she can't reach it while you work it out. My bet would be that anxiety is the cause , so enriching her environment , playdates etc. may help.
She is miserable, and it was during the summer last year that she had the same issue with her tail. No fleas or flea poop.
Welcome, Was last years spot, the SAME time of year? Are the black spots really tiny? Can you pick them off? Is it Flea poop?
You may want to consider a second opinion from another Vet! This looks pretty bad, I wouldn't wait! Let us know what you find out......Good luck, Karla
There are several reasons for why I dog would do this.. They range anywhere from hot spots, Alopecia, Dermatitis, to Pythiosis. It could possibly be anxiety and she chews her tail for relief. I would try to watch her actions closely and do as much research as possible... I hope you're able to figure it out. Poor baby is probably miserable. :(