94 Fowl Cholera 



fectiou is produced by an injection into the breast muscles, a yellow gelatinous in- 

 filtration of the subcutaneous tissue develops at the point of inoculation around 

 which the surroumling muscles show a yellow discoloration and necrosis. Mice maj 

 also be used for diagnostic purposes. In these the bipolar bacilli may be demonstrated 

 in large numbers in the blood. 



Treatment. At the onset of the disease the treatment of 

 the affected as well as the exposed fowls w^ith highly potent 

 immune serum is indicated (see page 95) ; otherwise, the af- 

 fected birds are given the customary weak solutions of disin- 

 fectants, which may be added to the drinking water. These 

 solutions, viz., iron sulphate, salicylate acid, tannin (i/> to 1%), 

 sulphuric or hydrochloric acid (2%), may also be given in 

 tablespoons or teaspoons (Ward and Stange give a 1 to 1500 

 or 2000 corrosive sublimate solution as drinking water). The 

 same methods may be also applied as preventive measures 

 against the disease in healthy birds which are threatened by 

 infection. The subcutaneous injection of a 5% carbolic acid 

 solution (Nocard, Barberio) is followed by little or no bene- 

 ficial results. 



Prevention. Great care should be exercised in order that 

 the introduction of the disease by the purchase of new birds 

 may be prevented. In addition to careful examination of the 

 source, it is advisable to keep new birds separated for at least 

 1 week, and only after that period should they be allowed to 

 mingle with the birds of the flock. 



If the disease has already appeared in a flock, entirely 

 healthy birds should be taken to an absolutely clean place with- 

 out delay. ■ Those already affected or suspected should im- 

 mediately be slaughtered or taken to a separate place for treat- 

 ment. The carcasses should be buried deep, or, still better, 

 burned. After burning or burying the droppings,^ the walls 

 and roosts of the chicken houses as well as the drinking vessels 

 and containers used for feeding, should be scalded with hot 

 water or washed with hot lye. They should also be sprinkled 

 with lime, and the previously cleaned floors should be sprayed 

 with a 3% creolin or lysol solution. Airing of the chicken 

 houses for several days promotes good results from this method 

 of prevention. The droppings from the affected as well as the 

 healthy birds should be collected at least once daily and burned. 



Immunization. Formerly attenuated cultures were used 

 for this purpose, while recently the immunization with blood 

 serum is more extensively employed. 



I. Immunization with attenuated cultures (Pasteur's 

 method). According to the investigations of Pasteur (1880) 

 the bacteria of chicken cholera in bouillon cultures are gradually 

 attenuated under the influence of the atmospheric air until after 

 about two months standing they lose their virulence entirely. 

 If allowed to stand for a shorter time the bacteria are attenuated 



