First off, I have to question the original diagnosis of an "ear infection" at 7 weeks old. Diagnosing otitis in that age group is unusual and its fairly hard to do considering how narrow the ear canals are. At any rate, assuming the kid had fevers he should have been admitted to a hospital for at LEAST blood and urine work, and probably should have gotten a lumbar puncture as well. Standard 48 hour sepsis work-up w/ IV antibiotics (ceftriaxone 100mg/kg q24h or amp/gent).
The rate of cross-allergenicity between later generation cephalosporins and penicillin is low enough that I would still prescribe it, provided that the mother was savvy enough to monitor for problems and take quick action if there was an issue. Yes, you can use azithromycin but IMHO thats clearly an inferior 2nd line agent for otitis.
I wouldnt use cipro for otitis, but I think the risk of tendon rupture cited in dog studies is way overblown; we can and do use fluoroquinolones in the pediatric world when there's not another good agent available. I've never seen any adverse reactions to it. The doses that result in tendon rupture are higher than anything we would use in kids anyways from the studies I've seen about it.