210 Diseases of the Genital Organs 



a bull weighing 2000 pounds and suffered a fracture of the 

 pelvis. The injury was not sufficiently serious to prevent 

 her giving birth in due time to a calf. In another instance, 

 a sucking filly was mounted by a large stallion which had 

 accidentally broken into a field with her, causing dislocation 

 of the sacro-iliac articulation on one side and fracture of 

 the iliac shaft on the other, rendering her useless for labor. 

 She was bred at two years, and destroyed at three years, 

 because of irremediable dystocia. 



It is desirable that young females which come in estrum 

 very early in life should be securely segregated from mature 

 males, not alone because of the undesirability of very early 

 breeding, but in order to avoid serious injuries from dis- 

 parity in size. It is also essential to remember that a male 

 breeding animal regularly confined, in case of accidental 

 escape, will attempt rape upon the most immature young, 

 as in the foregoing case, with serious or fatal results. 



The violent copulatory thrust of the bull occasionally 

 causes a fracture of the base of the tail or the caudal end of 

 the sacrum. I have observed it most frequently in Jerseys, 

 perhaps because the sacrum is relatively smaller and less 

 resistant than in other breeds. It seems to occur at the mo- 

 ment of the copulatory thrust. So far as known, it is not 

 subject to remedy. The result is usually caudal paralysis, 

 with a lateral curvature of the tail and caudal end of the 

 sacrum, disfiguring the cow and destroying the protective 

 value of the tail against flies, without otherwise injuring 

 the animal. 



B. False Copulation 



False copulation, or entrance of the penis into the anus 

 instead of the vulva, is possible in most domestic animals. 

 Harms records it as occurring in the mare, cow and sow. 1 

 have observed it only in the mare and, in all, four times, 

 though I have known of numerous other instances. It is by 

 no means rare and is highly dangerous. Its causes are va- 

 rious, but it is probably due largely to resistance on the part 

 of the female. Sometimes a female is thought to be in es- 



