62 o ACCIDENTS INCIDENTAL TO PARTURITION. 



it has been affirmed by highly competent authorities that it has been 

 observed in Cows which had not received any assistance during parturi- 

 tion. 



It can easily be understood why, if there is any material obstacle to the 

 passage of the fcetus — such as induration or torsion of the cervix, or a 

 malposition or deformity of the young creature — the violent contractions 

 of the powerful muscular layer of the organ should overcome the resist- 

 ance of some portion of its own fibres, and thus lead to a more or less 

 extensive solution of continuity, which may involve the other tunics and 

 produce complete perforation. Non-penetrating, or incomplete lacera- 

 tions, in the majority of instances occur towards the cervix, and are 

 usually longitudinal. Complete rupture may take place at any part of 

 the organ. 



This accident is more likely to occur spontaneously when there 

 chances to be an alteration in the texture, wholly or partially, of the 

 uterus wall ; though this predisposing cause does not appear to be so 

 often present in animals as in the human female, in which sudden per- 

 forating ruptures never take place when the uterine tissue is healthy. 

 Nevertheless, there can be no reason to doubt that in animals alterations 

 in the tissue of this organ may and do occur ; and, as in woman, this may 

 assume the form of anomalous development ; interruption of the normal 

 tissue by interstitial fibroids or cicatrices ; separation of the muscular 

 fibres by submucous fibroids, or by projecting thin parts of the foetus ; 

 inflammatory softening of some portions of the parenchyma during preg- 

 nancy ; or thinning of the wall at some part by pressiire. This pressure 

 may arise from contact with the brim of the pelvis, or exostoses in or 

 upon the bony canal. 



The exciting cause, however, proceeds from considerable mipediments 

 to the progress of labor, and the accident is due to the energetic contrac- 

 tions of the uterine walls and abdominal muscles, as well as to the pres- 

 sure, direct or indirect, of the diaphragm through the fully dilated chest 

 cavity. 



In such cases the rent may be so great, that the fcetus passes entirely 

 through it into the abdominal cavity, enveloped or not in its membranes ; 

 or only a portion of it has escaped through the tear, and it may be 

 extracted therefrom with more or less dA^oxAiy per vias naturales, and in 

 some recorded cases birth has taken place by the natural efforts, the 

 existence of rupture only becoming evident when the uterus was acci- 

 dentally extruded after birth. 



More frequently, however, the accident arises from artificial mechani- 

 cal causes, brought into operation in the course of manoeuvres for 

 effecting the extraction of the fcetus. The various instruments employed 

 may either tear or incise the uterus ; or the organ may be lacerated dur- 

 ing traction on the foetus when the " waters " have escaped, and its walls 

 closely envelop the young creature ; or during retropulsion or version. 

 The tenuity of the uterine parietes at this period, renders such an acci- 

 dent as laceration one of easy occurrence ; and, however large the tear 

 maybe during life, after death it usually appears much smaller, because 

 of the contraction of the muscular tissue. 



In all these cases, when the organ remains /;/ situ, the diagnosis is diffi- 

 cult, and generally it is only on post-mortem examination that the lesion 

 is discovered. Nevertheless, certain clinical symptoms are often 

 observed during life, which, if they were constant, might lead to a sus- 



