DISEASES OF THE LUNGS. 151 



play ; the nostrils open and close in quick succession, and 

 the flanks heave to and fro with great rapidity. Cold 

 sweats bedew the surface of the body ; the extremities 

 become icy cold, and the visible mucous membranes show by 

 their livid hue the deoxidized state of the blood. 



The pulse is much accelerated, and may reach 100-140 

 per minute ; it is feeble, oppressed, indistinct, and becomes 

 almost imperceptible in severe cases, and there is a tremor 

 all over the body. 



The heart's action, which is irregular and tumultuous 

 from the first, becomes still more embarrassed; the lungs 

 become more engorged ; and the breathing still more dis- 

 tressed, until, at length, death results from asphyxia or 

 suff'ocation. In more favourable instances, however, the 

 engorgement subsides, the heart regains power, the cir- 

 culation through the lungs is restored, and the animal soon 

 regains its normal condition. 



In some instances frothy blood is discharged through the 

 nostrils, from rupture of the engorged capillaries of the 

 lungs; in others, this haemoptysis, or discharge of blood 

 from the lungs, does not occur. Auscultation in some 

 cases reveals abundant minute crepitation, generally 

 diffused, but sometimes heard only over limited areas. 



It is unnecessary to say much of passive pulmonary con- 

 gestion, as this is treated of under the various diseases of 

 which it is an accompaniment. 



It will suffice to mention, that although the symptoms in 

 these cases are less marked, yet the disease is more frequently 

 fatal than in the acute form occurring as the result of 

 exertion in an unfit condition to bear the strain. 



Prognosis. — Is favourable, except in very severe cases. 



SecLuelse. — Acute congestion of the lungs is very liable 

 to recur for some time after apparent recovery, and is not 

 unfrequently followed by acute inflammation of the lungs. 



