10 Pathogenesis. 



The horses belonging to the Remount Depot of 

 Military Horses have contracted the disease and a con- 

 siderable number has already been lost. When the initial 

 outbreak took place we do not know, but since 1905 a 

 great many horses have died from deaths attributed to 

 the diseases of the spinal cord, of the heart, anemia, etc. 

 in the pastures of the Branches of the Remount Deport 

 at Hagino, Yamagata Prefecture, Kajiyazawa, Miyagi 

 Prefecture, Rokuhara, Iwate Prefecture. In 1907 it was 

 discovered that all the losses had been due to infectious 

 pernicious anemia. Ever since that date the disease has 

 invaded all the pastures of the Branches of the Remount 

 Dep6t and the maximum losses came in 1910, the num- 

 ber of the horses that died and were killed taken toge- 

 reaches over 500. Since then the number of patients 

 has decreased as the result of strictly carrying out the 

 preventive measures. As the virus is usually introduced 

 into the pastures of the Branches of the Remount Depot 

 through two-year horses, which look healthy, when 

 bought, and afterward prove to have been infected when 

 pastured in the summer, our constant effort to anihilate 

 the disease completely has not as yet been rewarded. 

 And even now fairly heavy losses take place every 

 year. 



III. PATHOGENESIS. 



A. Nature of the Disease. 



The great spread of infectious anemia in pastures is 

 due to the transmission of the virus from one individual 

 to another by insects. Very seldom are horses infected 

 through the alimentary canal in stables. 



Unless the disease is of a subacute nature and death 



