TRACHEOTOMY. 449 



if the animals are restive. The head must neither be raised too high, 

 nor turned on its own axis. It is easy to judge of the action of such 

 abnormal positions of the head by attempting to swallow whilst 

 the head is either turned much towards the right or left. Such 

 positions are, however, less dangerous in oxen. Very great care 

 is required if the drugs are not in complete solution, or if they contain 

 irritants. Should the animal cough when receiving a drench, 

 administration should be suspended. Rubbing the neck is not only 

 useless, but also dangerous, as coughing is thus easily induced. 



Large, firm objects can usually be removed from the air passages 

 only after tracheotomy. Removal is sometimes possible with the 

 help of suitable forceps. If necessary, the fissure in the trachea 

 can be lengthened, when the body may be forced out by the pressure 

 of the expiratory current. Tumours can sometimes be removed in 

 a similar fashion. 



(5.) TRACHEOTOMY. 



Tracheotomy consists in opening the trachea for the purpose 

 of inserting a tube or cannula for the passage of air. The operation 

 is adopted to prevent suffocation, or dyspnoea, arising from obstruc- 

 tion (oedema, abscess, tumour, paralysis, fracture, etc.) in the larynx, 

 pharynx, or nasal passages ; to remove foreign bodies from the 

 trachea ; and occasionally to carry out direct treatment of the interior 

 of the larynx or trachea. 



Tracheotomy is almost invariably restricted to horses, in which 

 animals impaired respiration is commonest and interferes more 

 seriously with usefulness. In ruminants diseases of the larynx are 

 uncommon, and when they occur the animals are generally 

 slaughtered. Owing to the comparatively long neck, and exposed 

 position of the trachea, the operation offers less difficulty in horses 

 than in cattle. 



In animals, and especially in horses, there is a wide field for 

 operation, comprising the space from the upper end of the trachea 

 to near its entrance into the thorax. Giinther prefers for the 

 operation a point about one-third of the distance from the larynx 

 to the chest, though he admits that it may be carried out higher 

 or lower without disadvantage. Lafosse chooses the space between 

 the third and fourth tracheal rings ; Krieshaber, that between the 

 larynx and trachea. As a rule, the space between the upper and 

 middle thirds of the neck is the point selected, because it is 

 convenient, interferes less with the appearance of the animal, 



R.S. G G 



