156 Roaring in Horses. 



taken that the cannula is not displaced while doing so. 

 The wound is kept open by the finger for a shorty time, 

 to allow any blood to escape ; afterwards the blood is 

 cleaned away from and around the wound, the face and 

 nostrils sponged to refresh the animal, and the body 

 clothed and legs bandaged, if the weather is cold. 



2. After-treatment. 



When able to walk after the operation, the horse is led 

 quietly into a loose box which has no litter on the floor, 

 and the head-collar is removed. It is very necessary, in 

 order to ensure healthiness of the wound, that the box and 

 its surroundings be kept scrupulously clean, the drainage 

 being good and the air sweet. The wound is to be left 

 open and undisturbed. Serosity and mucus will escape 

 from it for a short time after the bleeding has ceased, suc- 

 ceeded by slight purulent discharge as the healing process 

 goes on. The external wound is to be kept free from dis- 

 charge, and if flies are troublesome it may be dressed with 

 a weak solution of carbolic acid, or covered with a piece of 

 thin muslin, tied by tape around the neck. 



The advantages of removing the cannula soon after the 

 operation lie chiefly in the injury it is likely to inflict in the 

 trachea if left there for a considerable period ; respiration 

 is not so easy with as without it ; while its accidental dis- 

 placement or obstruction might be serious. 



Leaving the entire length of the external wound open is also 

 essential to success. Not only does this permit the horse 

 to breathe entirely through the aperture, and so obviates air 

 passing over the intra-laryngeal wound, but it also allows the 

 movements of the larynx to be greatly diminished, and 

 this still further promotes rapid and favourable healing ; 

 while it renders inspection easy, and any needful dressing 

 of the interior can be effected. Another advantage is 

 that the external wound, being immediately below the 



