There are different types of treatments are used in the different types of diseases. Based on the symptoms, you need to give the treatment of the fish. If your fish get the bacterial infection than you can use the Chloromycetin or doxycycline. If your fish facing the dewormer than you must have to treat it with the metrogyl and H4.
If your fish get injured so you need to use the melafix and other types of drug to treat the wound. It is better you can consult the fish expert to treat the infection of the fishes.