The fever should break within 48 hours of starting the antibiotic.
Unfortunately abx are grossly overprescribed and most ear infections are NOT caused by bacteria, but by viral infections on which the antibiotic has NO effect at all.
Then, because they are so frequently overprescribed, the small percentage that is typically caused by bacterial infections, might now have involvement of resistant strains, against which the first line antibiotics do no longer work.
My daughter went for 8 or 10 rounds of antibiotics for ear infections in an 8 month period around her first birthday - until we traveled abroad for a vacation and got her checked out there. The doctor (a regular pediatric doctor in Europe) was horrified to hear the treatment regimen and prescribed a mucolytic and medicated nosedrops to reduce the swelling in her sinuses and help the fluid drain from her ears. They do NOT routinely prescribe abx unless it is absolutely necessary.
My personal experience leads me to believe that US doctors may not have the latest information that is internationally available for the treatment of ear infections in infants... in addition the drugs we were prescribed are not available in infant doses in the US... really quite sad.
We brought an ample supply and will refill (these are OTC meds) when we go back. I usually give my daughter just one dose of nosedrops and mucolytic when she gets nasal congestion and that has really kept it at bay. We cleared this with our US pediatrician by the way, who agreed that it was ok.
We had been talking about getting tubes after our return from vacation, but after being treated in Europe my daughter's ear infections did not return. It's been more than one year now.
Unfortunately getting a second opinion will not help very much, since abx is the standard treatment in the US. You may want to consult an ND for alternatives...