Our American Pit-bull Terrier gets reoccurring ear infections. Interested in home remedies, ear & diet?

Are pits susceptible to ear infections? Is it due to food allergies? We’ve tried many expensive dog foods that she doesn’t seem to like as well as Pedegree. She is back on Pedegree. We’ve taken her to the vet many times & have an appt. even now. The ear infections come back after a little while. I hate that she has to take yet another antibiotic. She is worse now than she has ever been . Ear infection in both ears and passed worms this am. Her last RX 6 wks ago. She does not have a pen and sleeps indoors. She is not around other dogs and lives in the country if that matters. I would like advice on vitamins for her an ear wash recipe and any other advice on what may be the culprit and cure. Thanks.