44 



boring structures is very probable iu some cases, particularly in 

 pelvic peritonitis. The Ijaeteriological results hardly bear out the 

 theory of ^Yilliams that the organisms lie dormant in the genitalia 

 of the animals until the advent of sexual maturitj^, at which time 

 they acquire pathogenic powers. On the other hand, his clinical 

 observations seem to indicate that this may be possible. Calves 

 suffering from "calf infections" frequently do harbor organisms 

 in their genital organs, but whether or not they persist there till 

 sexual maturity is a matter of conjecture. The most logical theory 

 seems to be that animals from herds in which genital infections 

 are very severe, or those that have had severe attacl<s of scours 

 or pneumonia, are more susceptible to those infections, due to the 

 early lowering of their vitality. One bull in the department herd 

 certainly had a severe ordeal as a calf, but as a mature bull he 

 was highly fertile. Moderate sexual use and proper sexual hygiene 

 proljably had much to do with this. In the bull, infectjon of 

 some part of the genitals, during some period of life, is very con- 

 stant, however, whether or not it is productive of observable 

 changes in his breeding efficiency. The finding of the fine connec- 

 tive tissue strands and tufts on the serous surface of the tail of 

 the epididymis of practically all bulls examined, both sterile and 

 fertile, indicates past or present infection of the scrotal sac. The 

 vesicles and tail of the epididymis are, as stated previously, the 

 most commonly invaded tissues of the tract. The testes are less 

 frequently involved. 



While it is difficult to obtain irreproachable proof that the bull 

 is a disseminator of genital infections, the findings of clinicians 

 quite clearly indicate that this is true, and laboratory methods 

 tend to support this assumption. Williams believes that not only 

 may the bull infect the female with organisms whicli interfere 

 with the given conception, but that he often implants there organ- 

 isms which interfere with future pregnancies, and even with the 

 life of the individual in some cases. The high abortion and ster- 

 ility rate following the use of certain sires, and the appearance of 

 characteristic infections after seiwice to certain bulls, clearlj^ in- 

 dicate that in all probability the bull does eliminate with his 

 semen those organisms whicli produce lesions in his genital organs, 

 and are capable of infecting the female. W. L. Williams (48) 

 cites the case of a pure bred herd in which breeding had pro- 

 gressed satisfactorily until heifers had grown to breeding age and 

 a second bull was obtained. " Some cows of the old herd were 

 also assigned to the young bull which had not previously been in 

 service. The cows bred to the old herd bull continued to breed 

 normally. The cows and heifers bred to the new bull conceived 

 with difficulty or not at all. Those which conceived mostly 

 aborted, and those which calved had metritis and retained fetal 

 membranes. The two first cows in which pregnancy terminated 

 died of metritis." I have frequently had semen samples sent in 

 from bulls that were not only failing to get cows with calf, but 



