544 Veterinary Obstetrics 



as a bar to subsequent parturient paresis, but it does so indirectly, 

 in a manner which we do not comprehend because we have not 

 yet succeeded in fully defining the disease itself. 



Prolonged labor of every degree may occur in a way which pre- 

 vents us from drawing any fixed line of demarcation between 

 normal and abnormal birth. What may be an abnormal duration 

 of labor in one species of animal may be wholly natural in an- 

 other ; what may constitute abnormal birth in one animal of the 

 same species may be wholly normal in another animal ; or that 

 which may be normal in a given individual at one birth may be 

 wholly abnormal at another birth. We have already suggested 

 that in the mare the duration of labor is usually but a few min- 

 utes, while in the cow it is from two to ten times as long, and 

 may endure from two to four hours or even longer and yet run 

 an apparently normal course without material danger or incon- 

 venience for either the mother or the calf. It is constantly to be 

 borne in mind that in primipara, where the genital passages have 

 not previousl3' been dilated by a birth, the dilation is slow as 

 compared with animals which have previously given birth to 

 young. If a heifer has been in labor for several hours and the 

 cervix of the uterus is not fully relaxed, but the position of the 

 fetus, its size and condition, and the character of the birth canal 

 itself, all seem to be normal, there is no reason for great anxiety 

 and we had best await the efficiency of nature to accomplish the 

 desired result. 



If animals are debilitated, whether from old age or ineiBcient 

 feeding or care, they may be unable to normally give birth to 

 young, although the fetus is in every way properly presented 

 and the general condition of the genital organs is apparently nor- 

 mal. Heifers which are bred very young are liable to become 

 weak and emaciated on account of the extra burden placed upon 

 their nutritive systems by the pregnant condition, and thus arrive 

 at the period of parturition in an enfeebled state. In addition 

 there may be a relatively large fetus. 



In such animals labor pains may be wanting in vigor and efiE- 

 ciency and after a time may more or less disappear and eventu- 

 ally wholly cease. The uterine walls are so lacking in vigor, in 

 harmony with the general debility of the system, that they be- 

 come exhausted and their force diminishes or ceases. The feeble 

 pains may rupture the fetal membranes and permit the gradual 

 discharge of the fetal fluids. 



