484 PULMONARY CONGESTION. 



from repeated applications to tlio chest of the compound soap 

 and tincture of opium liniment, or even simple cantharides 

 Hniment ; this latter to be applied only once, and not repeated 

 until the scurf raised by the vesication is removed. When 

 weakness or want of tone with loss of flesh occurs, the work of 

 the animal ought to be lightened, and such tonics as iron with 

 nux vomica and gentian, or some preparation of arsenic, 

 administered. 



CHAPTER XX. 



PULMONARY CONGESTION — CONGESTION OF THE LUNGS. 



Definition. — A hypercemic condition of the pulmonary capillary 

 vessels, sometimes attended with extravasation from these into 

 air-sacs, and interconnective-tissue. 



Nature and Causation. — Congestion of the lungs, or engorge- 

 ment of the vessels of the pulmonary tissue by unnatural col- 

 lection or detention of blood there, may occur in the horse and 

 all animals as a precursor and accompaniment of inflammation 

 in pulmonary structures ; also in other local and general 

 diseased conditions, as in some cardiac affections, enteric 

 diseases, arthritic inflammations, and in some special epi- 

 zootics. 



In addition, hoAvever, congestion, or collection to repletion of 

 blood in the pulmonary vessels, occurs as an independent and 

 distinct condition, which is that to which we now chiefly refer, 

 and which we mean to indicate when not qualified by any 

 accompanying term explanatory of its origin or association. 



When of an acute character, and accompanied with capillary 

 haemorrhage, it is sometimes spoken of as pulmonary apoplexy. 

 This state of hyperaBmia, or lucmal engorgement, is recog- 

 nised as acute, and passive, or mechanical. The former is the 

 manifestation Avhich Ave most frequently encounter and most 

 readily recognise in our patient. Active congestion in the horse 

 is most frequently the result of — 1. Increased cardiac action, 

 without or apart from relative resisting power in pulmonary 

 vessels ; 2, All agencies which at other times or Avith other 



