Bella's scratching her ears !

Hi
Bella was at the vets on Wednesday to get spayed and she has had a buster collar on since. Yesterday she was trying to scratch her ears but couldn't, I just thought that the collar was annoying her, this morning I took the collar off her for while and she scratched her ears for about 10 minutes and black stuff came out, it didn't look waxy more like flakes, I looked in her ears and they looked ok, I took her buster collar off tonight for a while and she scratched again and a little of the black stuff came out, but ever since she has been shaking her head and desperatley trying to scratch her ears. I never noticed her doing this before wednesday. Does anyone have any ideas ? I was wondering if she could have caught something while at the vets, does that sound possible ?

Well, the scratching and black stuff indicates ear mites to me. Go back to the vet, have his ears checked, and get some drops, if necessary.