Snake Care and Health : Ball python with RI...please respond ASAP

[momoffive]

I own four ball pythons and my biggest (my female) has a respiratory infection (I know because I had a spider male who had all the signs and he died last week)

My husband, like so many in todays economy, lost his job and we cannot afford vet visits. I understand how to give injections to my snakes and have read up on Baytril, but can someone please, please tell me where I can get it without a prescription? Getting a prescription is not possible for me as I cannot afford the vet visit...i can only afford the bottle of baytril and I will need it if my others snakes fall ill (this female was in with my patsel male a few days ago before I knew she was sick)