16 Pathogenesis. 



4. Blood was drawn from a young horse of an 

 affected mare, before it began sucking, and was injected 

 intravenously into two healthy horses (Experimental 

 horses Nos. 554 and 615). Two showed typical symptoms 

 of the malady. 



5. A foal from an affected mare was stopped suck- 

 ing at the age of a little over four months and was 

 kept outside the stable. It became ill and died with 

 typical symptoms of infectious anemia. 



From the above experiments we may be able to 

 conclude that the virus is present in the milk of a 

 patient and that the virus also penetrates into the fetus 

 through the placenta. And the transmission of the disease 

 to the young seems to be accomplished more frequently 

 during its intrauterine life than through sucking virus- 

 containing milk. 



Experiments on Various Animals. 



In case the donkey contracts the disease, it ususally 

 shows acute symptoms and dies rather suddenly. As to 

 animals outside the equine family, the pig is most sus- 

 ceptible ; young goats and sheep also show slight febrile 

 conditions; calves, rats, guinea-pigs, rabbits and dogs have 

 no susceptibility at all towards the disease. 



Pig. 



1. Young pig.— 10 c.c. of the blood of a patient 

 was injected subcutaneously into a young pig. After 

 eleven days its bodily temperature suddenly rose as high 

 as 40.2°C., locomotion was markedly interfered with, 

 appetite became poor, the heart action forcible, frequent 

 shiverings, finally it fell into an unconscious state and 

 died after two days {vide accompanying table). 



