206 PNEUMONIA INFLAMMATION vF THE LUNGS. 



and forced from the inside of the tube. If the disease proceeds, the discharge become* 

 oloody, and then, and sometimes earlier, it is foetid. 



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

 ve cannot trace the air-tubes to their termination, the inflammation will penetrate 

 Tito the lobuli, and affect the membranes of the air-cells or divisions which they con- 

 tain. 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 neithei 

 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 sup- 

 ply 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 gene- 

 rally, 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. 



Here again the first step will be to bleed ; and here too will be the paramount 

 necessity of the personal attendance of some well-informed person while the animal is 

 bled. This is a disease of a mucous. and an extended mucous surface ; and while 

 our measures must be prompt, there is a tendency to debility which \v e should never 

 forget. Although the horse may be distressed quite to the extent which Mr. Charles 

 Percivall describes, yet he would not bear the loss of four pounds of blood without 

 fainting. No determinate quantity of blood will therefore be taken, but the vein will 

 not be closed until the pulse falters, and the animal staggers, and in a minute or two 

 would fall. This may probably effect the desired object; if it does not, it i? possible 

 that the practitioner may not have a second opportunity. 



The medical attendant should be cautious in the administration of purgatives, foi 

 the reasons that nave again and again been stated ; but if the bowels are evidently 

 constipated, small doses of aloes must be given with the febrifuge medicine, and their 

 speedy action promoted by injections, so that a small quantity may suffice. 



A blister is always indicated in bronchitis. It can never do harm, and it not unfre- 

 quently affords decided relief. It should extend over the brisket and sides, and up 

 the trachea to the larynx. The food, if the horse is disposed to eat, should be mashes 

 No corn should be offered, nor should the horse be coaxed to eat. 



PNEUMONIA INFLAMMATION OF THE LUNGS. 



The intimate structure of the lungs has never been satisfactorily demonstrated 

 They appear, however, to be composed of minute cells or pouches, into which the ail 

 is at length conducted, and over the delicate membrane constituting the divisions of 

 which myriads of minute blood-vessels are ramifying. The blood is not merely per- 

 jneating them, but it is undergoing a vital change in them ; there is a constant decom- 

 position of the air, or of the blood, or of both; and, during the excitement of exercise, 

 that decomposition proceeds with fearful rapidity. Then it can readily be conceived 

 .hat a membrane so delicate as this must be, in order that its interposition shall be 

 no hindrance to the arterialisation of the blood ; so fragile also, and so loaded with 

 blood-vessels, will be exceedingly subject to inflammation, and that of a most dan- 

 gerous character. 



Inflammation of trie substance of the lungs is the not unfrequent consequence of 

 all the diseases of the respiratory passages that have been treated on. Catarrh, 

 influenza, bronchitis, if neglected or badly managed, or, sometimes in spite of the 

 most skilful treatment, will spread along the mucous membrane, and at length involve 

 the termination of the air-passages. At other times, there is pure pneumonia. This 

 cpllular texture IP the primary seat of inflammation. It i p ofter.. so \\i the over-worked 

 horse. After a long and hard day's hunt, it is very common for horses to be attacked 

 by pure pneumonia A prodigiously increased quantity of blood is hurried through 

 these small vessels, for the vast expenditure of arterial blood in rapid progression 

 must be provided for. These minutest of the capillaries are distended and irritated, 

 their contractile power is destroyed, inflammation is product d, mechanical injury is 

 effected, the vessels are ruptured, blood is poured into the interstitial texture, and 

 ii)tense inflammation and congestion, with all their train of falal consequences, ensue 



The following are the most frequent causes of pneumonia. A sudden transition 

 f ?om heat tr cold *, a cbangfe from a warm stable to a colder one ; a neglert of the usua 



