BY HERNIOTOMY. 549 



sac appears most markedly strangulated. This point lies in the 

 inguinal canal a little below the internal abdominal ring, as Hering 

 and French veterinarians have noted. Reduction may now some- 

 times be effected by introducing a finger into the inguinal canal and 

 pressing and kneading this point, especially if an assistant pass his 

 hand into the rectum and pull gently on the bowel. Moller prefers 

 to carry out this accessory manipulation personally, because, whilst 

 it is important to exercise a steady and regular pull on the portion 

 of bowel in the inguinal canal, the spermatic cord must not be grasped, 

 as it would limit the pull. With a little practice the parts may easily 

 be distinguished through the rectal wall. Should these attempts 

 fail, the operator must proceed to internal herniotomy, that is, incision 

 of the tunica vaginalis and of the abdominal ring. The seat of in- 

 carceration may generally be felt by introducing the finger, and 

 division must be made at that point. 



According to Moller's experience, in old stallions strangulation occurs 

 about an inch below the internal abdominal ring. In geldings, on the 

 other hand, he has generally found the annulus abdominalis the narrowest 

 point. Possibly the heavy pull of the testicle on the spermatic cord, which 

 becomes fan-shaped in the abdomen, exercises some influence on the funnel- 

 shaped, or, as the French call it, the " hour-glass " dilatation of the tunica 

 vaginalis, which is most noticeable towards the inner abdominal ring. 

 The continuous pull can without doubt produce a dilating influence of 

 that kind, which would explain the greater predisposition of old stallions 

 to protrusion of the bowel at the point indicated. 



Girard constructed for this operation two long hernia knives, 

 one in the form of a greatly enlarged straight tenotome, and the 

 other in that of a bent tenotome. The ordinary herniotome (Fig. 397) 

 may also be employed, or in case of need, a blunt-pointed bistoury. 

 The abdominal ring must be incised near its anterior angle, and 

 in an outward direction. Towards the middle line, and in the neigh- 

 bourhood of the posterior angle, are certain blood vessels, which 

 must be avoided, and any lengthening of the anterior angle is apt 

 to be followed by tearing of the inner oblique abdominal muscle. 

 Even when the point of incarceration has only been incised to the 

 extent of two or three lines, reposition becomes easy, and indeed 

 usually results from the pull of the abdominal viscera themselves. 

 Paty recommends pouring extract of opium and belladonna dissolved 

 in oil into the tunica vaginalis. This certainly lubricates the contents 

 of the hernial sac and assists reposition ; but plain oil sterilised by 

 boiling would serve the same purpose. After reduction, treatment 

 is the same as in non-strangulated rupture, that is, a clam or tape 

 ligature is adjusted as high up as possible over the spermatic cord and 



