Originally Posted by Sunflowers
Typical reaction to being bitten by fleas. You may went to get a flea comb and check that area.
It sounds exactly like fleas, but what you saw was flea 'dirt'.
You'll need to hit this on all bases if true. Flea shampoo her, then put some topical from the vet between her shoulders. Vacuum and flea bomb the house.
If fleas you need to get on it NOW cause there are fleas jumping off her and laying eggs in the house that will hatch and get everywhere. It's not just about what is walking around on your dog.
Fleas on Dogs and What You Can Do About Them | petMD