THE EESPIEATOEY APPAEATUS. 317 



serves to give mucli information as to their respiratory 

 uses. 



Beonchitis — Inflammation of the Lining Membrane of 

 the Trachea and Bronchial Tubes — is of comparatively fre- 

 quent occurrence in the ox, depending either on the ordi- 

 nary cause of respiratory disorders, exposure, or on 

 extension of inflammation from the larynx and Schnei- 

 derian membrane. Also it may be due to mechani- 

 cal causes, the entry of solid or liquid particles into 

 the air-passages during temporary laxity of the glottis, 

 and the development and residence of parasites in the 

 lungs. 



Symptoms. — Besides the ordinary signs of inflamma- 

 tion the pulse is remarkably hard, and the respirations are 

 increased out of all ordinary relation to the beats of the pulse, 

 the inspirations being difiicult, and each efi^ort short and 

 imperfect. The animal does not look at the side, nor flinch 

 at pressure on it. The cough is paroxysmal, frequent, and 

 very distressing. The visible mucous membranes are purple 

 through defective oxidation, and there is a considerable 

 amount of debility present, due to the same cause. Ausculta- 

 tion in the early stages gives various results according as 

 the larger or smaller air-tubes are involved ; later, both are 

 affected, as well as the lung -tissue in general. Rhonchus 

 or sibilus, according to the region auscultated, in the 

 early stages, and the mucous rale later in the attack, 

 may be present; sometimes, also, we find intermittent 

 loss of sound in some parts of the lung, due to mu- 

 cous accumulations plugging the bronchial tubes. In 

 some cases this latter condition may occur permanently, 

 and loss of small portions of the lung result. This 

 is much less important than the similar state in the 

 horse. The functionless parts atrophy and often burst, 

 and the neighbouring air-vesicles enlarge somewhat. 

 Percussion gives healthy results from every part of the 

 chest. The dry stage of the bronchi is succeeded by pro- 

 fuse discharge from the nostrils, which passes through 

 the usual phases, from watery to muco-purulent. This 

 relieves the inflammation, and recovery may now com- 



