Bovine Tuberculosis 729 



media. The cultures of the bovine bacillus tend toward alkalinity, 

 those of the human bacillus toward acidity. 



Pathogenesis — (a) Guinea-pigs.— The bovine bacilU are more 

 virulent than those of human tuberculosis, intraperitoneal inocula- 

 tion of the former producing death in adult animals in from seven 

 to sixteen days; of the latter, in from ten to thirty-eight days. Sub- 

 cutaneous inoculation of the bovine bacillus causes death in less 

 than fifty days; of the human bacillus, in from fifty to one hundred 

 days. 



(b) Rabbits. — Rabbits inoculated into the ear vein with the bovine 

 bacillus die in from seventeen to twenty-one days. Those receiving 

 human baciUi sometimes live several months. 



(c) Cattle. — Cows and heifers receiving intrapleural and intra- 

 abdominal injections of the human bacilli usually gain in weight and 

 show no symptoms. When examined postmortem, circumscribed 

 chronic lesions were found. Those inoculated with the bovine 

 bacillus lose weight, suffer from constitutional symptoms, and show 

 extensive lesions at the necropsy. Two-thirds of the cattle inocu- 

 lated experimentally with the bovine bacillus die. 



Lesions. — In general the lesions produced by the bovine bacillus 

 are rapid, ^ extensive, and necrotic. Many bacilli are present. 

 Those produced by the human bacillus are more apt to be productive, 

 chronic, and contain relatively few baciUi. The bacilli of human 

 tuberculosis produce lesions with many giant cells; those of bovine 

 tuberculosis, lesions with rapid coagulation necrosis. The lesions 

 resulting from the intravenous injection of human bacilli into rabbits 

 resembled those observed by Prudden and Hodenpyl* after the 

 intravenous injection of boiled, washed tubercle bacilli. 



From these data it is evident that the bovine bacillus is by far 

 the more virulent and dangerous organism. 



At the International Congress on Tuberculosis, held in London, 

 1901, Koch expressed the opinion that bovine tuberculosis was not 

 communicable to man. The matter is of the utmost importance to 

 the medical profession and of far-reaching influence upon many im- 

 portant sanitary measures that bear directly upon the public health. 



Koch's opinion, being opposed to all that had been believed before, 

 received almost universal disapproval. The papers by Arloing,t 

 Ravenel, J and Salmon§ contain evidence showing that under certain 

 conditions bovine tuberculosis can be communicated to man. 



Ravenelll has reported 3 cases of accidental cutaneous inoculation 

 of bovine tuberculosis in man. All were veterinary surgeons who 

 became infected through wounds accidentally inflicted during the 



* "New York Med. Jour.," June 6-20, 1891. 

 f "Lyon Med.," Dec. I, 1901. 



% "Univ. of Pa. Bulletin," xiv, p. 238, 1901; "Lancet," Aug. 17 and 19, 1901; 

 "Medicine," July and Aug., 1902, vol. viii. 

 ] "Bull. No. 33, Bureau of Animal Industry," U. S. Dept. of Agriculture, 1901. 

 I "Phila. Med. Jour.," July 21, 1900. 



