EXPERIMENT STATION BULLETINS. 435 



TUBERCULOSIS IN FOWLS. 



Circular No. 12. 



Tuberculosis is a very widespread disease. Nearly every species of 

 animal may contract this disease under certain conditions. We are 

 familiar with tuberculosis chiefly as it occurs in human beings, cattle, 

 swine, and chickens, and its economic impoi-lance depends largely upon 

 its occurrence in these animals. It is with ihis disease in poultry that 

 we wish to deal here. A knowledge of the disease is of importance to 

 both consumers and producers, and especially to the latter since they 

 are both producers and consumers. 



Tuberculosis in fowls is said to be a serious pest in Europe, but 

 authentic reports of it in this country are not sufficient to warrant us 

 in stating that it is i>revalent. As a matter of fact, we do not know how 

 widespread the disease is. We know that it exists to a considerable 

 extent in Ontario, Canada, in Oregon and California, and that it has 

 been found in New York. It has been found in flocks in several counties 

 of Michigan, and occasionally in market chickens. 



A single illustration will help to emphasize the importance of this 

 disease : In January, 1911, a large flock of mixed Black Minorcas and 

 Brown Leghorns was found in Livingston county, badly affected with 

 tuberculosis. In the spring of 1910 this flock consisted of nearly 300 

 birds. By January, 1911, there were about 160 left. A positive diagnosis 

 was made as a result of the examination of a bird sent to this laboratory. 

 An arrangement was made whereby 140 birds were killed and dressed, 

 and the remainder (those visibly affected) were sent to the laboratory 

 for experimental work. Of the 140 birds killed, 40 were found to be 

 tuberculous. 



Tuberculosis is found in a great variety of species of birds. It is 

 reported in the common fowl, pea fowl, ducks, turkey, goose, pigeon, 

 dove, grouse, partridge, pheasant, stork, crane, canary, finch, owl, swan, 

 vulture, ostrich and parrot. There are several types of the microorganism 

 causing tuberculosis and we do not know whether the avian type is 

 responsible for the disease in all these species. The relation of tuber- 

 culosis in birds to that in mammals is still an unsettled question. It 

 is known that some birds, such as parrots and canaries, die of tubercu- 

 losis of human origin. The avian germ is not easily made to reproduce 

 the disease in mammals, but experiments have resulted in its successful 

 transplantation into rabbits, guinea pigs, and a cat as well as pigs. Rats 

 and mice are said to die of avian tuberculosis in bird parks of zoological 

 gardens, and in turn infect birds that feed upon their dead bodies. It 

 is not easy to produce tuberculosis in chickens by feeding human tuber- 

 culous sputum, but there is a record of a whole flock of chickens in- 

 fected by the sputum of a tuberculous man who used to sit in the yard 



