Dystokia 569 



It is diflficult to state whether the comparative frequency of 

 dystokia is dependent directly upon species or if it is due to the 

 prevailing environments or care of the species of animal under 

 consideration. The comparative frequency of dystokia in the 

 cow and mare varies greatly in different regions of the country, 

 according to the character of the breeding industry. Veteri- 

 nary obstetrists, as a whole, agree that the cow is far more sub- 

 ject to dystokia than the mare. For example, Fleming cites 

 two Danish veterinarians, who have had r6 to 19 cases of dys- 

 tokia in the cow to one in the mare, even though there were 

 more horses than cows reared in their districts. Our own ex- 

 perience does not verify this view, and is probably due to the 

 difference in the character of our practice as compared with that 

 of most writers upon veterinary obstetrics. 



We constantly met in our private practice with more cases of 

 dystokia in the mare than in the cow, although in our judgment 

 there were annually more cows than mares giving birth to j'oung 

 in our territory. It should be explained, however, that the calves 

 which were bred in our territory were raised for beef purposes 

 and that the pregnant cows were habitually out of doors through- 

 out the entire year, were well-fed and strong, were not bred until 

 they had attained sufficient size that they would not be likely to 

 suffer from dj-stokia because of immaturity, and were usually 

 sent to the butcher before they had attained extreme old age. In 

 these animals dystokia was exceedingly rare, and it was only in 

 exceptional cases that there was any great difficulty in parturition. 



One other element probably served largely to make an apparent 

 difference in the frequency of dystokia in the two animals in our 

 practice. Owners very generally did not hesitate to attempt 

 assistance to the cow and very frequently succeeded fairly well, 

 so that our attention was not called to the cases. In mares, 

 which, in our territory, were of high value, the owners usually 

 desisted from any attempts at bringing about delivery themselves 

 and we were more or less promptly called. These considerations 

 may have served to make the difference in our experience as 

 compared with that of other obstetrists. 



It is constantly to be noted that dystokia runs parallel in fre- 

 quency to the confinement of the animal. Consequently we find 

 that those females which are most closely housed and least exer- 

 cised are the ones which suffer most frequently and seriously 



