208 PNEUMONIA. — INFLAMMATION OF THE LUNGS. 



marked by the observant practitioner ; and he regards witli fear and despair the livid 

 or dirty brownish hue that gradually creeps on. 



The unfavourable symptoms are, increased coldness of the ears and feet, if that be 

 possible ; partial sweats, grinding of the teeth, evident weakness, staffcrering, the 

 animal not lying down. The pulse becomes quicker, and weak and fluttering; the 

 membrane of the nose paler, but of a dirty hue; the animal growing stupid, comatose. 

 At length he falls, but he gets up immediately. For awhile he is uj) and down almost 

 every minute, until he is no longer able to rise ; he struggles severely ; he pitcously 

 groans; the pulse becomes more rapid, fainter, and he dies of suil'ocaticn. The 

 disease sometimes runs its course with strange rapidity. A horse has been destroyed 

 by pure pneumonia in twelve hours. The vessels ramifying over the cells have 

 yielded to the fearful impulse of the blood, and the lungs have present' li < . e mass 

 of congestion. 



The favourable symptoms are, the return of a little warmth to the extremities — the 

 circulation beginning again to assume its natural character, and, next to this, the 

 lying down quietly and without uneasiness; showing us that he is beginning to do 

 without the auxiliary muscles. These are good symptoms, and they wilT rarely 

 deceive. 



Congestion is a frequent termination of pneumonia. Not only are the vessels 

 gorged — the congestion which accompanies common inHammation — but their parietea 

 are necessarily so thin, in order that the change in the blood may take place although 

 they are interposed, that they are easily ruptured, and the cells are filled with blood. 

 This effused blood soon coagulates, and the lung, when cut into, presents a black, 

 softened, pulpy kind of appearance, termed, by the farrier and the groom, rxilennens, 

 and being supposed by them to indicate an old disease. ]t proves only the violence 

 of the disease, the rupture of many a vessel surcharged with blood ; and it also proves 

 that the disease is of recent date, for in no great length of time, the serous portion of 

 the blood becomes absorbed, the more solid one becomes organized, the cells are 

 obliterated, and the lung is hepatized, or bears considerable resemblance to liver. 



In every case of pneumonia, early and anxious recourse should be had to ausculta- 

 tion. Here, again, is the advantage of being perfectly acquainted with the deep 

 distant murmur presented by the healthy lung. This so-md is most distinct in the 

 young horse, and especially if he is a little out of condition. On such a horse the 

 tyro should commence his study cf the exploration of the chest. There he will make 

 himself best acquainted with the respiratory murmur in its full state of development. 

 He should next take an older and somewhat fatter horse ; he will there recognize the 

 same sound, but fainter, more distant. In still older animals, there will sometimes 

 be a little difficulty in detecting it at all. Repeated experiments of this kind will 

 gradually teach the examiner what kind of healthy murmur he should expect from 

 every horse that is presented to him, and thus he will be better enabled to appreciate 

 the different sounds exhibited under disease. 



If pneumonia exists to any considerable degree, this murmur is soon changed for, 

 or mingled with, a curious crepitating sound, which, having been once heard, cannot 

 afterwards be mistaken. It is caused by the infiltration of blood into the air-cells. 

 Its loudness and perfect character will charncterize the intensity of the disease, and 

 the portion of the chest at which it can be distinguished will indicate its extent. 



The whole lung, however, is not always affected, or there are only portions or 

 patches of it in which the inflammation is so intense as to produce congestion and 

 hepatization. Enough remains either unafrected, or yet pervious for the function of 

 respiration to be performed, and tlie animal lingers on, or perha])S recovers. Bv care- 

 ful examination with the ear, this also may be ascertained. Where the lung is im- 

 pervious — where no air passes — no sound will be heard, not even the natural murmur. 

 Around it the murmur will be heard, and loudly. It will be a kind of rusliing po\ind ; 

 for the same quantity of blood must be arterialized, and the air must jinss more rapidly 

 and forcibly through the remaining tubes. If there is considerable inflammation or 

 tendency to congestion, the cre])itatin<r. crackling sound will be recognized, and in 

 proportion to the intensity of the inflammation. The advantages to be derived frrm 

 the study of auscultation are not overrated. It was strong language lately applied by 

 an able critic to the use of auscultation, that "it converts the organ of hearing into an 

 organ of vision, enabling the listener to observe, with the clearness of ocular demon- 



