Baytril is the antibiotic I was trying to think of. Thank you momosgarage
. If this is bacterial the Baytril injectable mixed with a PH balanced ear wash is the best, I have found. I would also look to switch foods to non-grain duck, venison or fish protein. But give the food switch time as it will take awhile to get the old allergins out of her system.
Please think about the allergy testing as I think it is key if no mites are found. FYI, in my area ear mites are very rare but some vets want to always try and blame it on mites. They have ear mite medicine to sell, ya know.
Best of luck,