540 



INGUINAL HERNIA IN THE HORSE. 



a largely developed testicle in old stallions. In the latter, inguinal 

 hernia sometimes results during copulation, the erect position causing 

 the viscera to be pressed towards the pelvis and into the inguinal 

 canal, which is dilated in consequence of the thighs being turned 

 outwards. 



The condition is rare in geldings, because it is either cured by 

 castration or leads to the death of the animal, and because dilatation 

 of the abdominal ring very seldom happens late in life. The earlier 



Fi<;. 394.— Incomplete inguinal hernia. (The fig. 



shows the position of the inner abdominal ring 

 and the course of the external pudio artery.) 



Fit;. 395. — Inguinal hernia 

 of the horse. (Hering.) 



the colt is castrated the smaller does the inner abdominal ring become, 

 and this explains why it is so small in most geldings, though the 

 latter are not exempt from inguinal hernia. The swelling of the 

 spermatic cord after castration distends the canal and favours hernia ; 

 the contents are usually intestinal, but omental hernia also occurs, 

 though in stallions intestine is much more frequently found. Some- 

 times both intestine and omentum are present in the sac which is 

 formed by the tunica vaginalis reflexa, dartos, and skin. 



Symptoms. The scrotum is increased in size by the entrance of the 

 viscus, but to a very varying degree ; in cases a careful search may 



