no OPERATIVE TECHNIQUE. 



exit. The point of the needle is then grasped with fingers or 

 forceps, and withdrawn through the upper orifice, bringing with 

 it the tape with which it has been threaded. If, however, the 

 eye is in the point of the needle the tape is not inserted until the eye 

 appears through the upper wound. The tape is then passed and the 

 needle withdrawn, leaving the tape in position. The tape, which 

 must be at least twice as long as the channel to be produced, is 

 secured by firmly tying the ends together or by attaching each 

 end to a transverse piece of rubber tube. The disadvantage of 

 uniting the ends consists in the danger of the loop so formed 

 catching on a hook or other object or being grasped in the horse's 

 teeth, and the entire seton being torn out. To prevent this the 

 horse should be tied up or a side-stick applied. In dogs a muzzle 

 must be put on. 



To increase the action the seton is smeared with irritants, and 

 is daily moved up and down. As soon as suppuration occurs, free 

 drainage should be secured by fomenting the orifices daily and gently 

 stroking the channel from above downwards. The seton may be 

 left in position from eight to twenty-one days. To remove it the 

 upper end is snipped off with scissors and the tape drawn downwards. 



Inserting a frog seton demands certain special precautions. 

 The horn around the point of the frog having been thoroughly 

 thinned, an incision is made above the bulbs of the heel, and the 

 special needle, with its convex side directed towards the tendons, 

 is thrust downwards towards the point of the frog, the foot mean- 

 while being extended as far as possible. The needle should appear 

 near the point of the frog. The ends of the tape are knotted 

 together and a dressing applied. 



Blood-vessels may be wounded in passing setons, but as only 

 small twigs are usually affected no special precautions are called 

 for. Where nerves are injured paralysis may result, and in some 

 cases tendons, tendon sheaths, and joints have been opened. Passage 

 of a seton under fasciae or the panniculus sometimes produces extensive 

 suppuration and burrowing of pus. \\^here a seton is left too long 

 in position the walls of the channel become thickened ; whil^ 

 should the animal not be carefully secured and watched the seton 

 itself may be torn out. 



An operation now almost entirely discarded is the insertion of 

 " rowels," " issues," or " plugs." An issue was produced by incising 

 the skin and thrusting a foreign bod}', like a fragment of leather or 

 of white or black hellebore, into the subcutaneous tissue. In 

 horses the spot most often chosen was the chest, close to the 



