[Presence of the bacterial kidney disease in salmonid fish in Quebec (author's transl)]

Abstract Presence of the bacterial kidney disease in salmonid fish in Quebec During the summers of 1979 and 1980, wild and hatchery fish were analysed for the presence of the bacterial kidney disease (BKD) agent in salmonid fish in Quebec by the indirect immunofluorescence technique. The causative agent of BKD was detected in all hatcheries tested. Ten to 25% of the fish were positive. The presence of this agent was independent of age and species. We were unable to detect the BKD in fish from the rivers in the northern part of Quebec (over the 50th parallel). The first detection of BKD in Quebec was made in the spring of 1979 in a hatchery. A high mortality occurred in fish over a year old. The majority of the fish were positive by immunofluorescence and the bacteriun was isolated from some fish. Three weeks before the disease appeared, six ponds received fish from this hatchery. No mortality was observed in those ponds and in the middle of the summer the percentage of carrier fish by immunofluorescence was approximately 20%.