Also, with a new vet do explain which antibiotics he's already been given, they can lose their effectiveness after a while. And not every antibiotic will work with everyone. When I had my first-ever ear infection as an adult, I went through 3 courses of different kinds of antibiotics before they had any effect at all - they said it was a "fractious" infection, and kept asking was I sure I hadn't had "X" antibiotic before. I explained that I had never ever taken any antibiotics for anything ... and thankfully the fourth different one actually wiped it out.

The company that made the good allergy med I took for ten + years stopped manufacturing it, so now, if I don't add a decongestant to my allergy meds from March - November, I end up with ear infections. No fun, so tell you baby I can empathize.