EOAEING. 283 



be not unfrequently either remote or proximate causes of 

 Eoaring ; anything, in fact, which directly irritates the glottis, 

 or produces either an active or passive closure of its opening, 

 may either remotely or proximately cause a horse to become a 

 permanent Eoarer. 



A Tumour situated within the hollow of the neck is gene- 

 rally considered to produce difficult breathing (when such 

 exists), in consequence of pressing upon the trachea, and nar- 

 rowing the channel within. This is an error; the difficulty 

 which attends the breathing from such a cause, arises in all 

 probability, from the tumour pressing either upon the trunk of 

 the recurrent laryngeal or some of its branches, which pres- 

 sure induces either complete or incomplete paralysis of the 

 muscles to which this nerve is distributed. The effect is, 

 snoring in the breathing, and the presence, to a greater or less 

 extent, as the case may be, of all the attendant symptoms of 

 asphyxia, and, in all probability, of the animal ultimately 

 becoming a Eoarer — especially if the pressure upon the recur- 

 rent laryngeal be not either speedily removed, or its function 

 for a time completely suspended. The latter is at all times 

 the most practicable, and the way to effect it is by making an 

 artificial opening into the trachea a few inches below the 

 larynx, and inserting a tube within. The great length of the 

 trachea of the horse, and its readiness of access, renders the 

 operation of Bronchotomy a very simple and a very harmless 

 affair. In every case of disease which involves the larynx, and 

 disturbs its function and internal economy, it should be resorted 

 to. It affords, for a time, complete rest to the organ ; and 

 during that time our undivided attention can be given to the 

 subjugation of the disease, with an internal satisfaction which 

 cannot be experienced by any one depending upon the old 

 method of treatment. 



