Can you post some pictures of the foot in question? Up close and in focus, all parts. Many times antibiotics are not necessary, or will be ineffective unless all the infection is removed first. If any remains, then it will regenerate.Where do you get antibiotics for bumblefoot? I’ve been treating my girl for two months and she’s not well yet! Foot still swollen and area around the hole that’s trying to act like it’s healing is still very hard!
If we can see what you are dealing with, it would help in giving advice. Also description of what you have done up to now for treatment.
Many of the common antibiotics have been pulled and are only available by prescription now, which means a vet. The vast majority of the time I don't use antibiotics beyond a topical ointment that is available over the counter, or sugardine.