ROARING IN HORSES. 15 



II. 



TREATMENT. 



The knowledge of the causes of roaring 

 accompanying pulmonary affections has given 

 rise to a prophylactic treatment, to which 

 several authors have drawn attention. By 

 the administration of alteratives — notably of 

 iodide of potassium — it has been sought 

 to prevent the compressive and atrophying 

 action of the hypertrophied bronchial glands 

 on the left inferior laryngeal nerve, but the 

 efficacy of the medicine is most uncertain. 

 Perhaps in many cases where no action is 

 manifested, the paralysis of the recurrent is 

 due to the pressure exercised upon it by 

 the inflamed lung or of the extension of 

 the inflammatory process, which in the first 



