534 Veterinary Medicine. 



History of the Disease. Luis Calendrini da Silva Pacheco 

 says the malady was unknown on the island until 1830, when, on 

 account of the great excess of wild horses and their devouring 

 the pastures needed for the more valuable cattle, great numbers 

 were killed and their hides marketed. This continued for over a 

 year without any attempt to dispose of the carcasses. These ac- 

 cordingly lay in heaps in a damp climate, under the equatorial 

 sun, in a condition of putrefaction, exhaling the most offensive 

 odors. Stimulated by frequent complaints, the government or- 

 dered that the carcasses should be burned to ashes, but no success 

 was accomplished, in one case 800 bodies having been merely 

 roasted a little on the surface. The district around Chaves con- 

 tained the greatest number of horses, there the greatest number 

 were killed, and there the disease broke out. A number, vari- 

 ously estimated at from 25,000 to 60,000 were driven into the 

 little bay of Juncal and killed by burning the grass, which, how- 

 ever, did not at all consume the bodies. The disease attacked first 

 the capivaras (rodents) in the district of Chaves, killing off the 

 the whole race ; then the wild and domestic swine suffered, and 

 finally it ravaged the equine race, and though confined to Chaves 

 for two years it was extended through sales of horses and raged 

 with such fury that in five years not a horse was left alive in the 

 island, except a small remnant of a few hundreds in Chaves, 

 where the infection started. 



Causes. The microbian cause of the disease has not been 

 definitely ascertained, so it is idle to speculate whether we have 

 to deal with a saprophyte which has taken on deadly pathogenic 

 properties, or whether the infection was carried to the island by 

 winged insects or birds attracted by the decaying carcasses. 



Certain conditions may be named as accessor}^ or favoring 

 causes. The wild horse often escapes so long as he is on the 

 pasture, but when lassoed, taken to the corral and broken, he 

 will die in four to six days. This suggests that the infection is 

 laid up and preserved in the corrals or stables, the mangers or 

 racks, or possibly in the water supplies. The contact with even 

 the reins (harness) of other horses is alleged to be a prominent 

 cause of infection. Another significant point is that around 

 every hacienda, within a radius of a mile, there are numbers of 

 carcasses, so that there is every opportunity for the infection of 



