Foot and Mouth Disease. 317 



aud swine. Man however is susceptible as are also horses, dogs, 

 cats and fowls, when they are inoculated or fed upon the in- 

 fected milk or other products. It is doubtful if any warm- 

 blooded animar enjoys an immunity. 



History, Geographical Distribution. Toward the middle of the 

 eighteenth century this disease prevailed in Central Europe and 

 England. The latter country stamped out both this and the 

 Rinderpest, but it continued to prevail on the Continent and was 

 re-imported into England in 1839. It reached America through 

 an importation from England to Montreal in 1870, but owing to 

 more or less effective quarantine, to the absence of cattle traffic 

 from east to west, and above all to the prolonged confinement in 

 yards and stables during our northern winter, it burnt itself out 

 in the course of the year. In Asia it has prevailed from time 

 immemorial, aud it was imported into South America in 1870. 



Etiology. This disease has long been known as caused by 

 infection alone. Excluded from England in the middle of the 

 eighteenth century it did not appear again until re-imported in 

 the middle of the nineteenth, and then speedily overran the 

 whole island except the breeding districts into which strange 

 stock were never taken. In South America it was unknown 

 until imported from the Old World into the Argentine Republic 

 and then it made a wide extension aud maintained itself where 

 the stock was kept on unfenced ranches. In our fenced North- 

 eastern states it died out aud has not re-appeared. 



The infection is especially resident in the vesicles or aphthse. 

 From the mouth this is distributed, with the abundant drivelling 

 saliva, on pastures, roads, feeding and drinking troughs, ponds, 

 streams and halters, and readily communicates the disease to 

 healthy stock following in the same places. From the feet and 

 especially the interdigital space, it is left on the vegetation, build- 

 ings, yards, cars, boats and all other possible media to infect 

 other stock in turn. From the teats it mingles with the milk so 

 as to infect the young suckling and all animals and men to whom 

 the milk may be given. It may become dried on litter and other 

 light objects and carried by the winds, or it may be carried on 

 the feet of men or animals including birds, but apart from this it 

 is not readily diffused and oftentimes a broad highway may set a 

 limit to its propagation. 



