New compounds for the control of bacterial gill disease

BACTERIAL GILL DISEASE, a common epizootic among hatchery fish, can be controlled by copper sulphate dips, as stated by Davis (1945), or by prolonged treatments with Roccal, as noted by Fish (1947). The use of copper sulphate is not without danger because of variation in toxicity according to the hardness of the particular water supply; also, the toxicity and efficacy of Roccal have varied considerably in different lots. Neither copper sulphate nor Roccal will cure in one treatcent a well-established epizootic of bacterial gill disease. For these reasons, a series of new disinfectants has been tested in the laboratory in an attempt to find a more effective cure and preventive for bacterial Eill disease. One of these tested, pyridylmercuric acetate, was suggested by Wan Horn and Katz (1946).