186 DISEASES OF HORSES AND CATTLE. 



CHAPTER XIV. 



HORSE POX (VARIOLA EQUINA). 



This is a pustular disease, making its appear- 

 ance most commonly on the fetlocks and pasterns, 

 but may be found on other parts of the skin or the 

 mucous membrane of the nose, and cases have 

 been reported where the mucous membrane of the 

 lungs became affected. On account of it breaking- 

 out on the pasterns it has been mistaken for grease 

 in the heels. This disease usually makes its ap- 

 pearance as an epizootic. It appeared in this 

 form in Canada in the winter of 1876; hundreds 

 of horses were laid up at the same time. It start- 

 ed in Montreal, and spread rapidly by contagion. 

 The first symptoms noticed in the majority of cases 

 were: The horse was dull and slightly stiff, the ap- 

 petite usually remained good; next, slight swell- 

 ings of the fetlocks, and if rubbed with the hand 

 they would be hot and tender to the touch, and 

 soon hard, rather flat lumps, from the size of a pea 

 to that of a half-dollar, could be felt. These soon 

 sunk in the center and a small piece of skin would 

 drop off, leaving a pit from which was discharged 

 a copious, thin gray fluid, which would irritate the 

 parts it passed over, causing them to become sore. 

 If it lodged around the coronet for some time, it 

 would cause a separation of the hoof, and in some 



