Sorry... *Baytril.
As for the antibiotic injection, thank your vet for not giving your cat Convenia. It is meant *only* for skin infections and it is the drug that killed my boy.
You can boil water on the stove, pick him up and walk him over to it. Stand close to it as the steam is rising. He will appreciate the warmth. Dont stand any closer than if you were cooking. I did this for my baby boy whenever he had congestion and rocked him. He always appreciated it. It helped...