636 Veterinary Obstetrics 



fetus, until the tail may be reached and traction applied to it, or a 

 hook implanted in the anus or about the buttocks, so that traction 

 may be applied to the tail end, causing it to advance until the 

 hind legs may be secured and the traction applied to them. 

 When the posterior limbs have been secured and the feet have been 

 brought into the passage, it yet remains to rotate the fetus and 

 convert the dorso-ilial into the dqrso-sacral position, after which 

 the rules for delivery in posterior presentation, dorso-sacral 

 position, apply. 



D. Extension and Adjustments of the Extremities. In 

 dealing with the attitude of the fetus during parturition, we have 

 described the normal position of the extremities and have noted 

 that, when they become materially deviated, they produce more 

 or less serious obstacles to the expulsion of the fetus. The de- 

 viations with which the obstetrist must deal are those of the 

 head, neck and limbs. 



The correction of these deviations must be carried out anterior 

 to the pelvic cavity, within the abdomen. It is consequently 

 essential, in most cases, that .the fetus be repelled in order to 

 bring about these corrections. It should be constantly remem- 

 bered that, in a large proportion of cases, repulsion of the body of 

 the fetus, and those extremities which are presenting normally, 

 has a constant tendency to bring about a correction of the devi- 

 ation. 



If the head is deviated to the right or the left, upward or down- 

 ward, repulsion of the fetal body tends constantly to cause the 

 head and neck to become extended. The reflexed head comes 

 in contact with the uterine walls, which resist its retreat while 

 the body is being repelled, and the head then tends to come for- 

 ward into its normal attitude. The same is more or less true 

 with most of the deviations of the extremities, which are con- 

 stantly aggravated as the fetus advances toward the vulva, and 

 tend as constantly to be ameliorated or even overcome when the 

 fetus is repelled into the uterine cavity. 



In addition to the two foregoing factors, the securing of room 

 and the natural tendency for these parts to become extended in 

 their proper position during repulsion, the veterinarian must in- 

 telligently apply his knowledge of mechanics and anatomy to 

 his task. If the head is reflected to the left side of the fetus 

 along the right side of the mother, it is very evident that, if 



