196 
TRACHEOTOMY. 
though its value is not great. It consists of a special forceps (see 
figures 83 to 87), with jaws bent at right angles to the limbs and externally 
ground to a sharp cutting edge. When closed, the head of the instru¬ 
ment is readily thrust through the skin and into the trachea; the jaws 
are then opened and the canula slid into position between them. The 
figures very clearly show the instrument and the mode of using it. 
(2) Incision into the trachea is most generally practised. The trachea 
may either be split or a portion excised from one or more rings. The 
splitting, although it increases the difficulty in introducing the canula, 
Figs. 83, 84, 85.—Thompson’s tracheotome. 
is sometimes preferred where the tube is likely to be only temporarily used, 
is less apt to cause deformity and stenosis, and hence is generally com¬ 
mended in acute diseases like strangles for foals and race-horses, in which 
even slight stenosis is dreaded. The excision of a portion of the trachea 
facilitates the introduction and removal of the canula for cleaning, and is 
specially desirable in such chronic cases as paralysis and contraction 
connected with the nose, larynx, or trachea. Experience does not justify 
the belief that stenosis is more apt to result when the cartilage is excised 
than when it is split. 
Tracheotomy is conveniently performed whilst the horse is standing ; 
casting usually aggravates any dyspnoea present. The animal should 
