PNEUMONIA. INFLAMMATION OF THE LUNGS. 269 



It has not infrequently happened that when horses have been turned out foe 

 early to grass, or without gradual preparation, pneumonia has supervened. 

 Few are, under any management, so su hject to pneumonia as those who, in 

 poor condition and without preparation, are turned into a salt-marsh. 



On the other hand, a sudden and considerable change from cold to heat may 

 be followed by inflammation of the lungs. Many horses perish in the dealers' 

 stables from this cause. The circulation is considerably quickened ; more 

 blood, and that with more than natural rapidity, is driven through the lungs, 

 previously disposed to take on inflammatory action. The sudden removal from 

 a heated stable to the cold air, for the purpose of examination, has also much 

 to do with the production of disease. 



Whether it is the consequence of previous disease of the respiratory passages, 

 or that inflammation first appears in the cellular texture of the lungs, pneumo- 

 nia is usually ushered in by a shivering fit. The horse is cold all over ; this, 

 however, soon passes off, and we have general warmth, or heat of the skin 

 above the usual temperature, but accompanied by coldness of the extremities 

 intense deathy coldness. This is a perfectly diagnostic symptom. It will 

 never deceive. It is an early symptom. It is found when there is little or no 

 constitutional disturbance ; when the pulse is scarcely affected, and the flanks 

 heave not at all, but the horse is merely supposed to be dull and off his feed. 

 It is that by which the progress of the disease may be unhesitatingly marked, 

 when many scarcely suspect its existence. 



The pulse is not always at first much increased in rapidity, and but rarely or 

 never hard ; but it is obscure, oppressed. The heart is labouring to accomplish 

 its object ; the circulation through the lungs is impeded ; the vessels are 

 engors.ed they are often ruptured ; blood is extra vasated into the air-cells; it 

 accumulates in the right side of the heart and in the larger vessels ; and in the 

 venous circulation generally there is a mechanical obstruction which the heart 

 has not power to overcome. Hence the obscure, oppressed pulse ; the inef- 

 fectual attempt to urge on the blood ; and hence, too, the remarkable result of 

 bleeding in inflammation of the lungs, for the pulse becomes rounder, fuller, 

 quicker. When blood is abstracted, a portion of th-e opposing force is removed, 

 and the heart being enabled to accomplish its object, the pulse is developed. 



It is only, however, in the early insidious stage that the flanks are occasionally 

 quiet. If the compressibility of the lungs is diminished by the thickening of 

 the membrane, or the engorgement of the vessels, or the filling of the cells, it 

 will be harder work to force the air out ; there must be a stronger effort, and 

 that pressure which cannot be accomplished by one effort is attempted over and 

 over again. The respiration is quickened laborious : the inspiration is 

 lengthened ; the expiration is rapid ; and when, after all, the lungs cannot be 

 compressed by the usual means, every muscle that can be brought to bear upon 

 the part is called into action. Hence the horse will not lie down, for he can use 

 the muscles of the spine and the shoulder with most advantage as he stands j 

 hence, too, the very peculiar stiffness of position the disinclination to move. 

 The horse with decided pneumonia can scarcely be induced to move at all; he 

 cannot spare for a moment the assistance which he derives from certain muscles, 

 and he will continue obstinately to stand until he falls exhausted or dying. 

 How eagerly does the veterinarian ask when he goes into the stable " Was he 

 down last night ?" And he concludes, that much progress has not been made 

 towards amendment in the case when the answer is in the negative. When the 

 patient, wearied out, lies down, it is only for a moment ; for if the inflamma- 

 tion is not subdued, he cannot dispense with the auxiliary muscles. He fre- 

 quently, and with doleful expression, looks at his sides at one side or at both, 

 accordingly as one or both are involved. There is not, however, the decidedly 



