CONTAGIOUS DISEASES OF DOMESTICATED ANIMALS. 3 63 



er, Zipplius, &c. The iufrequent recoguition of the disease in veal 

 calves is notewortby, beiug geuerally ouly a fraction of 1 per ceut., but 

 it must be added that tuberculosis in the dam, afiecting the fetus, 

 usually determiues the death of the latter, followed by abortion, and 

 that of those in which the disease stops short of this the tubercles often 

 rest circumscribed and inactive in an unimportant organ until the young 

 animal is more fully developed, or even grown up. 



(I have repeatedly seen abortions as the first indication of tuberculosis 

 in a herd, and calves of healthy breeds infected by milk grow to ma- 

 turity and then fall victims, where the ancient calcified products were 

 found side by side with the recent. It is further to be noted that the 

 calves more severely affected perish of indigestions, diarrheas, &c., and 

 are buried by the owners without any notification of the authorities. 

 These, therefore, cannot be fattened for veal. — J. L.) 



Goring noticed that in bovine tuberculosis 123 were infected by the 

 dam and 13 by the sire. The hereditary cases constituted 12 per cent, 

 of all cases of the <lisease. All veterinary and agricultural writers at- 

 tribute a most disastrous influence to in-and-in breeding (in infected 

 families). 



The special i)redisposition of animals with much loose connective tis- 

 sue has been already referred to. It is further noticeable that this is a 

 prerequisite to aptitude to fatten, and it is notorious that many fami- 

 lies of our best breeds of meat-producing animals are affected with 

 tuberculosis, while the disease is less prevalent among uninii)roved 

 races. 



(In this connection we must not ignore the close breeding of the latter 

 their residence in a hot forcing atmosphere, and their preservation for 

 breeding purposes, even when manifestly unhealthy, nor the free open- 

 air life and the prompt disposal of unthrifty beasts among the less val- 

 uable breeds. The disease being due to a specific germ, it should be 

 limited by the repression of that and not by abolishing in our meat- 

 producing animals those qualities which constitute their value. — J. L.) 



The conclusions as regards heredity are thus : 



1. Tliiit hoiedity is not without iutlaoiice apon the propagation of tuberculosis. 



2. That this uialady is trausuiitted aliku by the sire and the dam. 



:?. That the transmission of the morbific principle to the ovnle or fetus in course of 

 develoimient, is a cause of sterility in the parents, and frequently occasions abortions 

 and premature parturitions. 



4. That a fetus affected with tuberculosis rarely attains complete maturity or comes 

 into the world in conditions of normal viability. 



5. That notwithstanding these facts, we cannot deny the possible birth (perhaps in 

 great numbers) of tuberculous descendants which can develop and multiply cqua] 

 to animals, in perfect health and without any predisposition. 



Contagion as a cause of tuberculosis. — Lydtin refers to the above 

 proof of the transmission of the disease through the ovum, sperm, uter- 

 ine secretions, &c., and proceeds to offer further evidence of direct con- 

 tagion. He quotes Kuhling, Ivrunitz, Fromage, Huzard, Spiuola, Crugel, 



