microbial diseases of man and domestic animals 807 

 Foot-and-mouth Disease* 



Foot-and-moutli disease is primarily a disease of cattle, though 

 the other domestic animals and man may be attacked. The disease 

 is very contagious and is characterized by the eruption of vesicles in 

 the mouths, on the udders and on the skin surrounding the hoofs of 

 cattle. It is very prevalent in European countries. There have been 

 two outbreaks in the United States both of which were promptly eradi- 

 cated by vigorous repressive measures instituted by the Federal 

 authorities. 



The cause of this disease is an invisible microorganism which exists 

 in the lymph from the vesicles which form in the mouths and on the 

 feet of cattle. This virus has never been (;ultivated artificially. It 

 passes through the Berkefeld cylinder but not- through the finer-pored 

 Kitasato filters; it is quickly destroyed by formaldehyde, carbolic acid 

 and similar disinfectants. 



The disease is readily transmitted from one animal to another by 

 contact and the contagion may persist for some time in the manure, or 

 straw from infected stables. The milk of infected cows has been said 

 to produce the disease in children. 



Animals which recover from an attack remain immune for a short 

 time only; it is therefore not surprising that no satisfactory means of 

 artificial immunization has been devised. 



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 faU, 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.). 



* Prepared by M. Dorset. 



