584 SPORADIC DISEASES. 



practice witli some to place it against a wall, and threaten it 

 with the whip ; if it gvinits, it is further tested ; if not, it is 

 merely made to congh by pressing the larynx, and if the cough 

 has a healthy sound the animal is generally passed sound. 



This plan is not always satisfactory, and the better way is to 

 have the animal galloped, or if a cart-horse, to move a heavy 

 load some little distance, when, if it be a roarer, it is sure to 

 make a noise. 



Treatment of Roaring. — If the sound can be traced to any 

 removeable cause, the practitioner knows what to do, but the 

 removal of the causes of the form of roaring generally met with 

 is, however, a matter of great importance. Many experiments 

 have been tried ; in some rare instances the application of 

 blisters, or the actual cautery, to the skin of the laryngeal region, 

 has succeeded, not only in arresting the progress of the atrophic 

 change in the muscles, but in materially improving their strength 

 and tone ; but in order that this may prove effectual, the animal 

 is to be treated in the very earliest stages of the disease. In 

 addition to " iiring," I have only to suggest that the chlorate of 

 potash is worthy of trial, as it is found to have some power 

 in arresting fatty degeneration. 



In very bad roaring the sound may be modified by pads 

 attached to the bridle and fitted over the false nostril. These 

 pads regulate the quantity of air taken in at such inspiration ; 

 for it is observable that when a roarer is pushed in its work or 

 paces, that the nostrils dilate greatly, thus admitting a large 

 volume of air, which by its weight and pressure causes a further 

 falling in of the arytenoid cartilage and an increased constriction 

 of the laryngeal opening. If this method be inefficient, trache- 

 otomy is to be performed, and the tube kept in tlie trachea for 

 the remainder of life. Excision of the left arytenoid cartilage 

 (presuming that the left muscles are atrophied) has been sug- 

 gested by Giinther of Hanover, and has, I believe, been more or 

 less successfully carried out. The operation is to be performed 

 by making an incision through the skin into the superior part of 

 the trachea, the collapsed cartilage seized by forceps or tenacula, 

 and excised by means of a pair of scissors. 



It will be apparent that a bad roarer, no matter what the 

 means may be by which the sound is modified, is only useful for 

 slow work ; and lastly, I have always observed that confirmed 



