86o MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



FOWL PLAGUE* 



This disease (Hiihner Pest; Ger.: Peste aviaire; Fr.) of fowls, which 

 is to be distinguished from chicken cholera, is not known in the United 

 States, but has caused extensive losses of fowls in Europe, particularly 

 in Italy. Affected chickens cease eating, the feathers become ruffled 

 and the comb darker in color. The lesions found at autopsy are not 

 constant, but a pericarditis is usually seen. There may be, also, con- 

 gestion of the lungs, liver, and kidneys. The intestinal lesions are not 

 as marked as is the case in chicken cholera. 



Fowl plague has been shown to be due to an invisible microorgan- 

 ism which is present in the heart blood and in practically all of the 

 organs of the body. Most fowls are susceptible; guinea-pigs and mice 

 are refractory to the disease. The virus passes through Berkefeld 

 and Chamberland F cylinders; it is quite resistant to drying but is 

 destroyed by an exposure of half an hour to a temperature of 60. 

 Several authorities have passed the filtered virus through four or more 

 hens successively, thus demonstrating positively that the filtered virus 

 is capable of multiplication. 



HOG CHOLERA* 



The first recorded outbreak of hog cholera in the United States 

 occurred in Ohio in the year 1833 and it now exists in practically all 

 sections of this country. Hog cholera is most prevalent in the late 

 summer and fall, although outbreaks are reported at all seasons of the 

 year. All races of hogs are susceptible and the average mortality is 

 about 80 per cent. In the United States alone the losses from hog 

 cholera are estimated to average at least $15,000,000 annually. Hogs 

 only are attacked. This disease is supposed to have been introduced 

 into the United States through the importation of hogs from Europe, 

 where it is known under the names "swine fever" (Br.), " schweinepest" 

 (Ger.), and "peste du pore" (Fr.). 



The essential features of hog cholera may be briefly summarized as 

 follows: Extreme contagiousness. Symptoms of severe illness accom- 

 panied by fever, loss of appetite, weakness and diarrhoea. Haemor- 

 rhagic lesions in the various organs and lymphatic glands and round 



* Prepared by M. Dorset. 



