204 
DANGERS OF TRACHEOTOMY. 
on may injure the larynx by violently bending the head. This seems 
doubtful, provided the canula fits well to the neck. 
The evil results of tracheotomy comprise— 
(1) Mechanical pneumonia, produced by aspiration of inflammatory 
Fig. 97.—Superior orifice of the larynx and glottis of a horse affected with 
chronic roaring. 
secretions in such diseases as petechial fever and acute laryngitis, or from 
abscesses breaking into the pharynx or trachea. These complications 
are prevented by the use of the tampon-canula, made on the pattern of 
Trendelenburg and Hahn’s human canula. The former carries an india- 
rubber balloon, which, after being placed in position, may be inflated 
with a pair of bellows (fig. 105). Where foreign materials are present in 
the trachea, they should, as far as possible, be removed with a feather, 
