11 



eases of this class, immunity following it is very slight; cattle 

 often suffer from a second attack within a few weeks. 



The period of incubation is said by most authorities to be 

 from three to six days. In the present outbreak evidence has been 

 accumulated to show that it may be much longer. 



Another point of interest is the rapidity with which the dis- 

 ease runs its course and the promptness with which the lesions in 

 the mouth will disappear. The mortality is very slight. It is 

 given by different authorities at from one-half of one per cent, 

 to ten per cent., but occasionally there are outbreaks in which the 

 mortality is very high. The sequelae of the disease may be varied. 

 While many animals recover, a considerable percentage of them 

 develop abscesses in the udder and in other cases the hoofs drop 

 off. This latter seems to be particularly true of hogs. 



While the disease is not, in the beginning, very serious the 

 secondary lesions that follow, together with the loss of milk and 

 flesh during the disease, render it one of the most serious of the 

 infectious diseases of animals. 



Dr. Cope (Seventh International Congress of Veterinary Sur- 

 geons, Baden Baden, 1890, vol. 1, p. 184) stated at the Interna- 

 tional Veterinary Congress at Baden Baden in 1899, as follows: 



' "It is true that Foot and Mouth Disease rarely assumes a fatal 

 character, but the fact that nearly all classes of animals on the 

 farm are susceptible renders the neighborhood losses much greater 

 in the case of Foot and Mouth Disease, than rinderpest or pleuro- 

 pneumonia, which only affects cattle. In my country, where it has 

 existed for at least 50 years, it has caused enormous loss and in- 

 convenience, greater than that of all the other contagious diseases 

 combined." 



This is an exceedingly important statment when we call to 

 mind the statement of Dr. Gangee, that because of the neglect on, 

 the part of the British government, rinderpest and pleuro-pneu- 

 monia had cost Great Britain and her colonies more than four 

 hundred million dollars. 



Hafner stated, at the same congress, concerning the ravages 

 of this disease in southern Germany, that : 



"Foot and Mouth Disease had prevailed almost continually in 

 Germany for a long series of years and it had caused losses much 

 greater than all other episodic diseases combined. It had also been 

 found that the disease, instead of following a benign course as 

 formerly, had, during recent years, become very malignant. In 



