CHAPTER XXII. 



HORSE-POX.— COW-POX. 



Constitutional Grease or Horse-pox. 



Horse-pox is a vesicular disease of the horse communicable from 

 animal to animal by inoculation, but never infectious. It is 

 communicable by inoculation to man, and the attenuated virus 

 produces phenomena indistinguishable from the results of vaccina- 

 tion with cow-pox lymph. 



The existence of this disease of the horse had long been known 

 to farmers and farriers, but Jenner was the first to draw attention 

 to it in writing. " There is a disease to which the horse from his 

 state of domestication is frequently subject. The farriers have 

 termed it the grease ; it is an inflammation and swelling in the heel 

 accompanied at its commencement with small cracks and fissures, 

 from which issues matter possessing properties of a very peculiar 

 kind." Jenner gave several instances in which this disease was 

 communicated to man and to cows. 



Thus, a man named Merret attended to some horses with sore 

 heels and also milked the cows. The cows were infected, and the 

 man had several sores upon his hands. 



William Smith, on another farm, attended to horses with sore 

 heels and milked the cows also. The cows were infected, and on one 

 of Smith's hands there were several ulcerated sores. 



Simon Nicholls appUed dressings to the sore heels of one of his 

 master's horses and at the same time milked the cows, and the cows 

 were infected in consequence. 



A mare, the property of a dairy farmer, had sore heels, and 

 was attended to by the men of the farm, Thomas Virgoe, WUliani 

 Wherret, and WiUiam Haynes. They contracted " sores on their 

 hands, followed by inflamed lymphatic glands in the arms and 

 axLUse, shiverings succeeded by heat, lassitude, and general pains in 

 the limbs," and the disease was also communicated to the cows. 



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