Antimicrobials and fish: a review of drugs used to treat bacterial diseases of channel catfish and rainbow trout.

The principal bacterial diseases of cultured rainbow trout (Salmo gairdneri) and channel catfish (Ictalurus punctatus), and the antibacterials used in their treatment are briefly reviewed. Gram-negative bacteria predominate, and oxytetracycline is effective in treatment of infections induced by them. The only antibacterials now registered by the US Food and Drug Administration are sulfamerazine for the treatment of furunculosis in trout, and oxytetracycline for the treatment of furunculosis in salmonids and Aeromonas and Pseudomonas infections in salmonids and catfish. Registration 9/50 is now complete for the potentiated sulfonamide Romet-30 for controlling furunculosis in salmonids. Studies on the metabolism of antibacterials in fishes are limited, and are primarily concerned with tissue residue and elimination rate.