BRONCHITIS. 267 



the minutest ramifications of the air-tubes. When it is found to be thus 

 advancing, its progress should be carefully watched by the assistance of auscul- 

 tation. ^ The distant murmur of the healthy lung cannot be mistaken, nor the 

 crepitating sound of pneumonia; and in bronchitis the blood may be heard 

 filtering or breaking through the divisions of the lobuli, and accounting for 

 that congestion or filling of the cells with mucus and blood, which is found after 

 intense inflammation. Inflammation precedes this increased discharge of mucus. 

 Even that may be detected. The inflamed membrane is thickened and tense. 

 It assumes an almost cartilaginous structure, and the murmur is not only louder 

 but has a kind of snoring sound. Some have imagined that a sound like a 

 metallic ring is mingled with it ; but this is never very distinct. 



The interrupted whizzing sound has often and clearly indicated a case of 

 bronchitis, and there are many corroborative symptoms which should be regarded. 



The variable temperature of the extremities will be an important guide not 



deathy cold as in pneumonia, nor of increased temperature as often in catarrh 

 but with a tendency to coldness, yet this varying much. The pulse will assist 

 the diagnosis — more rapid than in catarrh, much more so than in the early 

 stage of pneumonia : not so hard as in pleurisy, more so than in catarrh, and 

 much more so than in pneumonia. The respiration should next be examined, 

 abundantly more rapid than in catarrh, pneumonia, or pleurisy ; generally as 

 rapid and often more so than the pulse, and accompanied by a wheezing sound, 

 heard at some distance. Mr. Percivall relates a case in which the respiration 

 was more than one hundred in a minute. Mr. C. Percivall describes an inte- 

 resting case in which the respiration was quick in the extreme ; and he remarks, 

 that he does "not remember to have seen a horse with his respiration so 

 disturbed." 



In addition to these clearly characteristic symptoms, will be observed a hag- 

 gard countenance, to which the anxious look of the horse labouring under 

 inflammation of the lungs cannot for a moment be compared ; also an evident 

 dread of suffocation, expressed, not by inability to move, as in pneumonia, but 

 frequently an obstinate refusal to do so ; cough painful in the extreme ; breath 

 hot, yet no marked pain in the part, and no looking at the side or flanks. 



As the disease proceeds, there will be considerable discharge from the nos- 

 trils, much more than in catarrh, because greater extent of membrane is affected. 

 It will be muco-purulent at first, but will soon become amber-coloured or 

 green, or greyish green ; and that not from any portion of the food being 

 returned, but from the peculiar hue of the secretion from ulcers in the bronchial 

 passages. Small orgauised pieces will mingle with the discharge, — portions of 

 mucus condensed and hardened, and forced from the inside of the tube. If the 

 disease proceeds, the discharge becomes bloody, and then, and sometimes earlier, 

 it is foetid. 



The natural termination of this disease, if unchecked, is in pneumonia. 

 Although we cannot trace the air-tubes to their termination, the inflammation 

 will penetrate into the lobuli, and affect the membranes of the air-cells or divi- 

 sions which they contain. There is metastasis of inflammation oftener here 

 than in pure pneumonia, and the disease is most frequently transferred to the 

 feet. If, however, there is neither pneumonia nor metastasis of inflammation, 

 and the disease pursues its course, the animal dies from suffocation. If the air- 

 passages are clogged, there can be no supply of arterialized blood. 



Like every other inflammation of the respiratory passages, bronchitis is 

 clearly epidemic. There is a disposition to inflammation in the respiratory 

 apparatus generally, but it depends on some unknown atmospheric influence 

 whether this shall take on the form of catarrh, bronchitis, or pneumonia- It 

 has not, however, been yet proved to be contagious. 



