r.Mim.li-.lL IIERXIA. 711 



ally repels the contained viscus, the margins of the abdominal opening 

 come into apposition, and, with the connective tissue, are inflamed and 

 soon unite. 



The needle of the syringe must not pass beyond the subcutaneous 

 connective tissue. 



3. CoxsTuicTiON. — Constriction of the hernial sac has been largely 

 reported to for the cure of umbilical hernia, with the view of destroying 

 it by mortification, causing adhesion above the part where this has 

 taken place, and including secondary cicatrisation when the sac has 

 sloughed away. The constriction is produced by li(ialurc, cla)ns, and 

 .suture. To apply these, the animal must, in nearly all cases, be thrown; 

 but before this is attempted, the tumour should be well examined, in 

 order to ascertain if it is reducible, if there are adhesions, the extent of 

 the abdominal opening, and the limits within which the constricting 

 iipparatus should be applied. 



The best position for reduction and constriction is the dorsal. The 

 animal, if a Foal, should be cast on a good bed of litter, and placed on 

 Its back. Very often the change of position reduces the hernia ; if not, 

 gentle manipulation and pressure will effect this, and then the empty 

 sac is pulled well away from the body, and the operation completed. 



The oldest procedure is ligaturing the entire mass of the hernial sac 

 by a piece of cord tied firmly round it, close to the body. This produces 

 at first a merely mechanical occlusion, but subsequently this is physio- 

 logical — exudation and organisation of the plasma thrown out by the 

 iiiHammatory process set up, producing adhesion of the peritoneal 

 surfaces. A piece of whipcord answers very well for this ligature, but 

 it must be drawn very tight around the neck of the sac, in order to pro- 

 duce its immediate and consecutive effects. 



To keep the ligature in place, some practitioners pass one or two 

 wooden pegs through the sac where it is encircled by the ligature; these 

 ])revent the twine being displaced by the swelling which quickly super- 

 venes. Sometimes a ring is employed, which is less in diameter than 

 the umbilical opening, and through which the hernial sac is passed 

 before the ligature is made. 



Some authorities prefer a double ligature, made by passing a double 

 cord through the base of the sac by means of a sacking needle, and tying 

 each separately or entirely round the sac. Sometimes the ligatures are 

 multiple ; and Legoff has recommended the employment of several 

 ligatures passing through the sac from apex to base, each becoming 

 tighter as the abdomen is neared. 



Ligatures are very simple and easily applied, but they have their 

 drawbacks, and these have led to their disuse. .\mong their dis- 

 advantages are uncertainty in their action — which is sometimes too 

 intense, at other times insufVicient ; the sac often sloughs off before 

 adhesion has taken place to such a degree as to sustain the weight of 

 the abdominal viscera ; and it has been pointed out that there is risk of 

 including or wounding the intestine. 



Very favourable results obtained by the elastic ligature in castration 

 have been reported by Guerin ;* this ligature might prove effective in 

 umbilical hernia. 



The procedure by clains is often resorted to, particularly when the 

 hernia is serious. The ordinary wooden clam (Fig. 225) may be employed, 

 ' Jiccucil de Ucdccine Vttirinaire, 1S77. 



