Biological Therapy 



133 



The symptoms of fowl cholera are essentially those of 

 an Intestinal infection. The droppings usually develop a 

 yellowish color and this is followed by diarrhoea. The 

 droppings may vary from a greenish pasty consistency to a 

 brownish red mucus or a viscous transparent fluid while the 

 feathers about the vent are badly soiled. Drowsiness and 

 disinclination to move are marked and this is followed by 

 congestion of the comb and later by cyanosis. Inappetence 

 is complete but the affected birds evidence great desire for 

 water while drooling of mucus is sometimes pronounced. 

 The temperature may be as high as 106 to 112 degrees F. 

 In the chronic form, usually observed toward the end of an 

 outbreak, the birds show a persistent diarrhoea. In these 

 cases progressive depression and emaciation is associated 

 with pale mucous membranes, lameness and arthritis. The 

 comb is congested or cyanotic. 



LESIONS. Petechiation and hemorrhages are charac- 

 teristic of this disease. These are generally confined to the 

 heart and duodenum although in some instances they may 

 also be observed in other portions of the intestinal tract and 

 the muscles. Involvement of the lungs is constant and 

 ranges from congestion to hepatization and caseation. The 

 air sacs contain a serofibrinous exudate while the intestinal 

 tract is filled with a pasty mass of feces mixed with blood. 



TREATMENT. On account of the septicemic nature of 

 the disease and the rapidity with which death occurs, no 

 pharmaceutical or biological treatment is of value. 



PREVENTION. Close attention to sanitation is of 

 utmost importance. All dead birds should be disposed of 

 quickly and carefully since other birds become infected from 

 eating these carcasses. 



Fowl cholera bacterin has proven of great value in 

 immunizing exposed birds. Although some investigators 

 have been unable to prove the immunizing value of this prod- 

 uct against artificial infections, others have been successful 

 in doing so. Of even greater value than such experimental 

 data is the fact that for several years fowl cholera bacterin 

 has demonstrated its ability to protect birds against natural 

 infection. This has caused bacterins to be almost uni- 

 versally used for prevention against fowl cholera, which 

 in turn has been followed by a marked reduction of losses 

 in infected flocks. The dose consists of 1 c.c. which is in- 



