My dog has excessive head shaking?

ania Asked: My dog has excessive head shaking?

I have just recently noticed that my dog has been shaking her head and scratching her ears a lot. I took her to the vet today & the vet took debris or something out of her ears. The vet took out brown gooey stuff, so what was that?? She listed stuff that I shouldn't give my dog, and one of them was pork, and my dad gives her pork. So i think that is it. SO the vet gave me ear drops that I have to give to my dog for 7 dayss and the vet & her assistant said that I should receive only positive results from this.The vet used that ear tool thingy and she thoroughly checked both of my dog's ears with it. And the vet used another tool to reach down into my dog's ear canal & etc and pulled out the debris. She looked into both ears a few times thoroughly with that ear microscope thingy. How would we know if it was ear mites? Because that is my MAIN concern. I thought she might have them. The vet examined the debris & did not mention that anything was moving. I checked on WebMd for dogs and it says that a symptom of an allergy (including food allergy) is itchy ears & ear infections. However.. None of these websites say that excessive head shaking is due to a food allergy. Do you think that my vet might be wrong?? I love my dog and I want the best for her.