158 ANNUAL REl'ORT OF THE Ofif. Doc. 



grams of feces were theu mixed with approximately 250 grams of 

 finely chopped carrots and fed to four guinea pigs set aside in separ- 

 ate cages for each bovine included in the examination. During one 

 of the 1 days on which feces was collected and fed, a rectal scraping 

 was taken from each of the forty cattle. A currette was inserted ap- 

 proximately 8 inches into the rectum, and on the withdrawal of the 

 instrument, feces clinging to the side of the bowel and some of the 

 superficial layers of the mucous membrane of the rectum were in- 

 cluded in the currettement. The material was placed in separate 

 sterile bottles. With an emulsion of the rectal scrapings, two of the 

 four guinea pigs fed feces from the same animal from which the 

 rectal scrapings was taken, were inject;^d subcutaneously over the 

 abdomen. Where the guinea ])igs died shortly following the injection 

 two, and in some instances four more guinea pigs were added to the 

 cage and injected before the feeding of the feces ended. In this 

 •Avay, at least two guinea pigs lived long enough for lesions to de- 

 velop at the end of the 11 days during which feces were fed. All of 

 the guinea pigs alive at the end of from 8 to 9 weeks were chloro- 

 formed and carefully autoi)sled. When lesions resembling tubercu- 

 losis were found, a rabbit was inoculated with an emulsion of one 

 of the lesions of at least one guinea ] ig included in the examination 

 of the feces of each bovine, (o determinj' whether or not the tubercle 

 bacilli would infect the rabbit, thereby giving an indication of their 

 virulence. 



The smear preparations of the feces collected were stained and a 

 large number examined microscoi»ically. 



The following tables include a brief description of each animal, 

 history, result of examination of feces (animal inoculation test) and 

 summary of lesions found at autoi)sy of the cattle slaughtered: 



