Drug Research Information Bulletin - Efficacy of AQUAFLOR® (50% Florfenicol) to Control Mortality in Chinook Salmon Diagnosed with Bacterial Kidney Disease

Bacterial kidney disease, caused by Renibacterium salmoninarum (Sanders and Fryer 1980), is a serious disease of cultured and feral salmonids (Earp et al. 1953; Smith 1964). Bacterial kidney disease (BKD) can result in significant mortality, and is wide-spread throughout North America, Chile, Europe, and Japan. Fish with BKD may or may not show external clinical signs (e.g., pale gills, exophthalmia, abdominal extension, skin blisters, shallow ulcers, or hemorrhages). Internally, infected fish are most frequently observed with creamy-white granulomatous lesions in the kidney (Inglis et al. 1993). Renibacterium salmoninarum is a small (0.5 × 1.0 μm), Gram-positive, non-acid-fast, non-spore-forming, non-motile, fastidious diplobacillus that grows best at 15 – 18°C, and not at all at 25°C (Inglis et al. 1993).