722 DISEASES OF THE KIDNEYS. 



CHAPTER LII. 



CONGESTIVE AND INFLAMMATORY AFFECTIONS OF THE 

 KIDNEYS. 



I. Renal Congestion. 

 Nature and Causation. — Hyperremia or excess of blood in 

 the renal structures, whether of an acute or passive chai\acter, 

 is/ like inflammatory action in the same organ, not a common 

 occurrence in the horse. When appearing, it is the result of 

 somewhat varying conditions and operating agencies, chief of 

 which are probably — (1) The immediate or previous existence 

 of some common or specific fever ; (2) The effect of the 

 ingestion or entrance into the system of some particular irri- 

 tant, as cantharides or terebinthinate compounds; (3) The 

 action of cold and damp applied to the external surface of the 

 body, causing retrocession of blood upon internal organs; 

 (4) Following external violence and injuries, with other local 

 disturbances of the kidneys following contiguous disease. 



In those cases of renal congestion, Avith febrile disturbance 

 and some other systemic changes, there is accumulated in 

 the blood a good amount of excrementitious and effete 

 material which is fiitly removed by the kidney. This hyper- 

 contamination of the blood very shortly results in hyperemia 

 of the structure of the kidney. The blood, in passing 

 through the vascular secreting structures, owing to its high 

 contamination, is detained a longer time in the vessels, in 

 order that the material to be removed may be separated by 

 the cell-agency ; this detention will, supposing the circulation 

 to be only kept up, involve an increased amount of pressure 

 and detention in the vessels behind, which gradually increasing 

 condition of hypera3mia may proceed to transudation of fluid, 

 or in some instances to rupture. 



Anatomical Characters. — When an oj^portunity is aftbrded of 

 examining the kidney where congestive action has been in 

 operation, the most attractive feature is a general fulness or 

 excess of blood, and consequent heightening of colour. Over 

 any section of the hypersemic organ there may be seen spots 

 of increased vascularity or ecchymosis corresponding to 

 the distended malpighian tufts. In some instances, when 



