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Journal of Agricultural Research 



Vol. XIII, No. 2 



fly to and from an infected farm. This belief is founded also upon the 

 knowledge that the virus of cholera exists in the carcasses of dead hogs 

 and on premises occupied by herds that are infected with the disease. 

 It is reasonable to assume that any agency likely to carry bits of tissue 

 from carcasses of hogs that have died of cholera, as for example, buzzards, 

 or any agency likely to carry particles of dirt from an infected hog lot, 

 as, for example pigeons, may serve to disseminate hog cholera. How- 

 ever, although there is ample ground for suspecting that certain birds 

 do at times carry the disease from one farm to another, absolute and 

 convincing evidence upon this point is lacking. The following experi- 

 ments were carried out v/ith the object of securing definite experimental 

 data relative to the likelihood of the conveyance of hog cholera by 

 pigeons. 



Two pens, 5 feet square, were placed facing each other, 10 feet apart, 

 and the space between was inclosed with wire netting. Small hinged 

 doors were cut in the sides of the pens, so that the pigs could be fed from 

 the outside. The upper portion of the front of each pen was left open. 

 The pens bore the numbers 19 and 22 (fig. i). 



Fig. I. — Diagram showing the arrangement of pens for pigeon experiments: a, b. Doors for feeding and 

 watering pigs; /, /, framework for holding wire netting. 



Experiment XIV. — Two pigs, No. 2283 and 2284, were injected with 

 hog-cholera virus and placed in pen 19 on September 18. Two unin- 

 oculated, susceptible pigs, No. 2285 and 2286, were placed in pen 22 on 

 the same date. Six pigeons were placed within the wire inclosure, the 

 birds having free access to both pens through the open fronts. No food 

 was placed in the space between the pens and the birds were forced to 

 go into the pens with the pigs to secure their food. 



The two injected pigs in pen 19 developed characteristic cholera 

 symptoms and died on September 26, showing extensive hemorrhagic 

 lesions and intestinal ulceration at autopsy. The pigeons were fre- 

 quently in the pen with the sick pigs and even sat on the bodies of the 

 sick pigs when these were in a moribund condition. They were also 

 frequently in the pen with the exposed pigs. 



