If a bacterial disease is suspected a culture
must be made to confirm the diagnosis.
It is far safer to use a
non-antibiotic bactericide and only if this treatment fails then an antibiotic resistance test be administered to the fish to determine the proper antibiotic to use.
The appropriate antibiotic should be administered for the
correct duration.
This is obviously beyond the scope of most aquarists and many vets. The problem of indiscriminate antibiotic dosing from non-prescription pet store antibiotics is a serious threat to public health and safety as it contributes to the creation of "super-bugs" - antibiotic resistant bacteria.
This would ordinarily not be a problem except for the one genus of bacteria:
Mycobacterium than can infect and even cause the death of humans.
This is an extremely serious problem and if we as aquarists continue to abuse antibiotics and more human life is lost our hobby could face some undesirable regulatory hurdles.