72 THE SURGICAL ANATOMY OF THE HORSE 



Tumours or other growths may thus be excised, a dry sponge being 

 tVeely used to absorb and remove any hemorrhage and prevent its 

 escape down the trachea. Extreme precaution in this direction must 

 be taken during the removal of purulent or other such accumulations 

 in the larynx. 



If, after examination, it is found that the condition necessitates a 

 prolonged operation, it is usual to insert a tracheotomy tube in order 

 that the respirations may not be interfered with, and through which 

 the administration of anaesthetics may be continued. It may also be 

 necessary to extend the wound by cutting through one or two rings 

 of the trachea. 



In such cases the operation wound is prevented from closing for 

 several days, in order that the interior of the chamber may be examined 

 and dressed frequently, and any complications which may arise at the 

 seat, attended to. 



Arvtenectomy 



This is the operation which has already been referred to as one of 

 the methods of relieving dyspnoea in cases of "roaring." By the term 

 is meant the excision of the arytenoid cartilage. 



The animal is secured, placed on its back, and the occipito-atlantal 

 joint fully extended, as in the operation previously described. A 

 tracheotomy tube should be inserted and the operation of laryngotomy 

 performed, the first two tracheal rings being included in the incision. 



The apex of the left cartilage (the one usually removed) is seized 

 with a long pair of rat-tooth forceps and with a sharp knife, or 

 preferably a pair of scissors, an incision is made through the lining 

 membrane as it passes from the surface of one arytenoid cartilage to 

 that of the other. This incision should then be carried along the 

 base of the cartilage, the cartilage being frequently twisted on its base 

 in order that its outline may be traced and followed. 



The course of the incision is next bent at right angles, and takes 



