Oh... poor Ashes. We've been dealing with her chewing her fur off for about 4 months now. We have treated it with steroid shots... which help, but only for a month... and we can't keep giving them to her or they can cause other issues. Because the last steroid shot has worn off, she has about a 3-inch by 2-inch patch of fur missing from the base of her tail up her backbone.
It's really so sad. She just chews and chews. We're working on food allergy as an option now, but that could take months to figure out if it is the problem.
In the meantime, I keep an eye on her whenever I'm home, trying to continually distract her from chewing at her bare bottom. This past weekend while I was swapping some laundry from the washer to the dryer, she walked into the laundry room (also where the litter boxes are). I stopped and watched her for a moment, but it appeared like she was going to go to the litter boxes. So, I continued transferring clothing to the dryer and started it up.
The next time I looked up, I didn't see her so I looked over my shoulder to see if she was at the litter boxes. Nope. Hmmm... okay. Shrugging, I figured she'd left the room so I turned my attention to putting laundry into the washer. That's when I discovered THIS: