Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a chronic disease that affects the salmonid fishes. Typical manifestations of BKD range from asymptomatic in carrier fish to internal and external clinical signs and mortality. The range of clinical signs may vary from one infected population to another or among individuals within the same infected population. Factors that might contribute to this range of disease expression are varying susceptibility of the hosts and differential pathogenicity or virulence of strains of the bacterium.

The purpose of this study was to evaluate the susceptibility of eight different salmonid hosts to various isolates collected from Lake Michigan and the Pacific Northwest, two geographic regions that are continually plagued with clinical BKD.