330 



LARYNX, TRACHEA AND BRONCHI. 



l)y the currents of air during inspiration and expiration causes spasm of 

 the glottis, fits of coughing and threatened suffocation. 



The diagnosis is not always easy, though examination of the nasal 

 cavities, the sinuses, trachea and chest gives negative results. Ausculta- 

 tion of the larynx may suggest the existence of the lesion, but an exact 

 diagnosis can only be attained by digital examination of the larynx 

 through the pharynx. 



The prognosis of these tumours is grave, because death from 



asphyxia may occur during an 

 attack of coughing or as a con- 

 sequence of the fits of suffoca- 

 tion. 



Treatment. As it is usually 

 extremely difficult, if not impos- 

 sible, to discover the exact nature 

 of the tumour, medical treat- 

 ment, except for instance in the 

 case of actinomycosis, is of very 

 uncertain value. 



Surgical treatment alone sug- 

 gests itself. Before attempting 

 an operation tracheotomy should 

 be performed and a metal canula 

 inserted. The animal having 

 been cast, and the ujjper laryn- 

 geal region anaesthetised by 

 means of cocaine, a vertical in- 

 cision is made in the median 

 line below the larynx, passing 

 through the skin, the vertical 

 junction between the neck mus- 

 cles and the three first circles 

 of the trachea, and access is 

 thus obtained to the larynx and subglottal region. The operation 

 should only be performed in exceptional cases, such as that of a valu- 

 able stud animal. 



Provided that the new growth has a well-developed pedicle it can be 

 ]-emoved through the mouth by the use of air ecrascur or simply by 

 tearing out. 



Fig. 170.— Sessile form of intra-laryngeal 



polypus. 



BRONCHITIS. 



Diseases of the bronchi in bovine animals reveal very different 

 characters, according to the nature of the primary cause, for which 



