838 LARYNX, TRACHEA AND BRONCHI. 



termination of verminous bronchitis. It is fomid in fully developed 

 animals, adult or old, and particularly in those inhabiting wet, cold 

 vallej's. 



It is characterised by frequent paroxysms of coughing, which appear 

 on the slightest provocation, such as the action of cold air on leaving the 

 stable or of the air of a confined space on animals returning from the 

 open ; concussion of the chest by the pleximeter, squeezing of the loins, 

 rapid 'movement, etc. 



This coughing is accompanied by the discharge of mucus, which 

 rarely arrives at the nostrils, but is swallowed in passing through the 

 pharynx. Such mucus is always thick, greenish yellow in colour, and 

 w^ithout smell. 



The respiration, although regular whilst the animal is at rest, becomes 

 accelerated on moving, and after attacks o£ coughing. It is sometimes 

 rapid and whistling. 



Percussion discloses neither partial nor complete dulness, but every- 

 where irregularly distributed mucous rattling and sibilant rales are 

 revealed by auscultation. 



There is no fever, the appetite is maintained, and, what is an even 

 more important point, animals in good condition preserve their flesh. 

 Interlobular pulmonary emphysema and emphysema resulting from 

 dilatation are inseparable accompaniments of chronic bronchitis, for 

 which reason the flank respiratory movement is frequently very 

 ^uarked. 



The diagnosis is of only moderate difficulty, because although in 

 certain conditions the disease may be mistaken for tuberculosis or 

 emphysema, it can be distinguished by bacteriological examination of 

 the discharge, by an injection of tuberculin, by careful auscultation, 

 and by consideration of the general condition. 



Lesions. The walls of the bronchi are thickened, the submucous 

 connective tissue is sclerosed, the muscular fibres are modified in 

 structure, and have become fibrous, while the epithelial layer is des- 

 quamated and suppurating. The peribronchial tissue also undergoes 

 sclerosis, and in certain cases the smaller bronchi present marked 

 dilatations resembling small caverns (bronchi-ecstasis). 



Treatment can never be more than palliative ; the aim should be to 

 prevent the lesions becoming aggravated, and to check the pathological 

 secretion from the bronchi, but the lesions already existent can never 

 be removed. Tar water should be perseveringly administered. Essence 

 of turpentine in doses of 2 to 2| drachms per day in electuary 

 (adults), creosote in doses of l^- to 1^ drachms, and terpine in 

 doses of f to 1 drachm give the best results, and produce a marked 

 improvement. 



