It sounds to me like there was an abscess that was originally kept partly under control from the baytril...but it needed to be lanced and cleared out in addition to the meds. Mouth infections can be very stubborn to take care of and they often spread to the tissue along the face and cheek. Did the vet do any sensitivity testing before prescribing baytril? It could be the bacteria is resistant to that particular med. I've also read that adding vit C to crix gutloads helps fight them off.