symptoms may be similar to furunculosis, may be refractory to sulfonamide 

 treatment. In case of mixed infections in which B. sa lmonicida is also 

 present, treatment with sulfonamides should be given. 



3. Treatment should be started before the results of bacteriological 

 examination are known. If bacteriological examination reveals infection 

 with pathogens v;hich are knovm to be refractory to sulfonamides, 

 treatment should be discontinued and other measures tried. 



4,. Mix sulfonamides very thoroughly with food of good cohesion. 

 Good practice is to mix sulfamerazine with dry feed (containing U 

 percent salt) before it is mixed with spleen and water. A satisfactory 

 ratio of meat, dry feed, and water is 2s2;l by weight. 



5. The effectiveness of treatment can be increased by removal 

 as often as practicable of all dead, sick, and runt fish which are less 

 likely to take adequate quantities of medicated food. 



6. Treatment should be repeated if the disease reappears. Very 

 prolonged treatment, or treatment -with inadequate dosage of drug may 

 result in the appearance of drug-fast strains of micro-organisms. 



7. Give fish plenty of food—about all they will take, but no 



8. Keep pools and troughs clean and observe strictly all sanitary 

 measures practiced in the control of infectious diseases. 



SmfHvIARY 



1. Furunculosis was first described by Emmerich and Weibel (189A)> 

 who found the causative agent to be Bacterium salmonicida . Since then, 

 the disease has been found widespread throughout Europe and the United 

 States. 



2. Numerous bacterial diseases of fish were described before 

 1894 but from the literature only can the general nature of these be 

 recognized. 



3. B. salmonicida is a short cylindrical organism. Gram- negative, 

 nonmotile, non-spore-forming with a tendency t'Owards pleomorphisra. 



4. The temperature range for grovrbh of B. salmonicida is 

 between 5° and 30° or 32° C. The optijnura growth temperature is stated 

 to be from 10° to 22° C. The organism has been recovered from fresh 

 water for up to 2 weeks. It is short-lived in salt water. The organism 

 survives longer in sewage material free from trade wastes (up to 67 

 days). The organism is an obligate parasite. 



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