It is generally believed that furunculosis was brought to the 

 Western Hemisphere mth brown trout introduced into the United States 

 from Germany, However, Fish (1937) feels it is far more likely that 

 furunculosis was originaliy a disease of rainbow trout ( Salmo gairdnerii) 

 of the Western United States. His conclusion is based upon the fact 

 that since rainbow trout in the United States possess a relatively high 

 inmunity to furunculosis j the disease must be one of long standing. 



Turning to Canada, furiinculosis has been reported by Duff and 

 Stewart (1933] from wild Rockly Mountain whitefish ( Pros opium williamsoni ), 

 Dolly Varden ( Salvelinus malma spectabilis ), and cutthroat trout (Salmo 

 ciarkii) of Elk River in southeastern British Columbia. 



RECORDS OF BACTERIAL DISEASES OF FISH BEFORE 189-^ 



Although furunculosis was not described until 1894-, there exists 

 the possibility that some evidence of it may be found in earlier records 

 of fish diseases. Williamson (1929) reviewed the literature with this 

 in mind but found it impossible to identify with certainty the bacteria 

 described in older records. The general nature of the infections 

 described in the earlier literature was, however, easily recognized. 



Fi'om 1866 to 1868 an epizootic disease among perch in Lake 

 Geneva was investigated by Forel {1868) and Forel and du Plessis (1866- 

 67). The fish died in very large numbers and the investigators 

 referred to the disease as "typhus" or "typhoid" of fish, apparently 

 because one of the symptoms was a yellow discharge from the cloaca. 

 The condition was that of a general infection, in which the bacteria 

 appeared in the blood during life<. Small superficial hemorrhages were 

 seen and there were degenerative changes in muscle, skin, and fins. From 

 the description, a secondary infection, possibly the same as that now 

 recognized as Saprolegnia ferax (Hume Patterson 1903) appeared to have 

 taken place, as patches of white mossy substance were seen on the skin. 

 Hemolysis took place in the blood vessels, but the bacteria disappeared 

 rsipidly from the blood after death. The organisms seen were short, 

 ?pindle-shaped rods, often in pairs. The mode of infection was not 

 discovered. Healthy fish kept in tanks beside diseased fish did not 

 beccme irifected. 



Fab.re-Domergue (1890) described a tumor-like lesion in Caranx 

 t rachuris and stated that the lesion was full of bacteria. The organisms 

 were often seen in pairs, and larger forms were twisted spirally. He 

 mB.de cultures on fish gelatin which was liquefied and assumed a green 

 fluorescence. The bacteria were, he thought. Gram-negative. Experimental 

 inoculation of cultures into several fish was unsuccessful. Williamson 

 (1929) felt that Fabre-Domergue (1890) had isolated Pseudomonas flucrescens, 

 although not in pure culture ^ and that the spiral organism present was 

 either a water vibrio or spirillum. She also felt that the lesion was 

 a coimective tissue tumor which had undergone degeneration and had been 

 invaded ty water organisms. 



