Tracheitis. 167 



swollen, velvety, friable condition of the mucosa, visible enlarge- 

 ment of the mucous follicles, more or less desquamation of the 

 epithelium (the surface, columnar, ciliated layer ; the middle, 

 pear-shaped or even the deep spherical layer). When the whole 

 thickness of the epithelium has been removed the basement mem- 

 brane shows clear, smooth and even glistening, while if the de- 

 struction has extended, still deeper distinct ulcers are formed. 



Symptoms are not prominent yet the windpipe is tender to 

 pressure at the affected parts, and in cases due to fracture of the 

 rings, puncture, tracheotomy or the presence of a foreign body, 

 this may be narrowly circumscribed. At first, with dry, thick- 

 ened walls, there is a loud blowing sound in breathing, followed, 

 on the advent of secretion, by a coarse mucous rile or gurgling. 

 In very severe cases the exudate may infiltrate the muscular and 

 subcutaneous connective tissue, causing, in solipeds, a distinct 

 swelling along the line of the trachea, and inducing more or less 

 difiiculty in swallowing. Fever will correspond to the severity 

 of the inflammation, there may be accelerated pulse and breath- 

 ing and elevated temperature, or there may be little or no con- 

 stitutional disturbance. 



In the croupous or diphtheritic form the fever runs higher, 

 dyspnoea is more marked, the breathing more stertorous, and 

 later the discharge of shreds of false membrane in the expectora- 

 tion is pathognomonic. In parasitic cases, the parasite may be 

 found in the sputa, in malignant growths the microscopy of the 

 expectoration may reveal the nature of the trouble, and in tuber- 

 culosis or glanders the testing with tuberculin or mallein will de- 

 cide the case. 



The treatment of these cases is essentially that of the laryngitis 

 or bronchitis of which they are the concomitant. Ivocalized 

 cases may sometimes be effectively reached and treated through 

 the opening made in tracheotomy. 



DEFORMITIES OF THE TRACHEA IN SOLIPEDS. 



Beside congenital distortions like truncated or double trachea, 

 these are examples in acquired deformity in otherwise well de- 

 veloped windpipes. 



Compression by an enlarged thyroid is a common and 

 fatal condition in newborn lambs, and in one newborn camel I 



