Symptoms, Course. 1005 



cases a hypertrophy of the left heart develops. Owing to the lasting hyperemia 

 and increased circulation the functioning portions of the kidneys actually eliminate 

 increased amounts of a dilute urine. On account of the raised blood pressure in 

 the free renal arteries the urine passes much more rapidly through the urinary 

 tubules and therefore a much smaller proportion of its water content is reabsorbed 

 by the blood than under normal conditions. The functioning of the healthy renal 

 portions, however, replaces that of the diseased parts only in regard to the elim- 

 ination of water and not in regard to the elimination of most of the solid constit- 

 uents. This, together with the arterial hyperemia in the excreting portions, is 

 responsible for the lowered specific gravity of the urine and also affords an explana- 

 tion why uremic symptoms may appear in this form of nephritis. 



The sensation of thirst is increased in proportion to the 

 increased elimination of urine. 



In dogs the hypertrophy of the heart may often be recog- 

 nized by the fact that the heartbeat is stronger, the cardiac 

 dullness enlarged to the left and upward and the aortic sound 

 accentuated; the pulse is strong and tense. 



The causal connection between the cardiac hypertrophy and the chronic inflam- 

 mations of the kidneys, especially the atrophic kidney, is not explained satisfac- 

 torily. According to Traube the hypertrophy of the heart is due to the occlusion 

 of numerous renal vessels, but it may be objected to this hypothesis that the 

 enlargement of the heart may occur also in . the diffuse non-indurative chronic 

 nephritis. A theory which was recently expressed by Senator and which had, in 

 a somewhat similar form been suggested already by Bright, appeared more accept- 

 able. According to this the metabolic products are retained in the blood in atrophic 

 kidney, and produce, by irritation, an increase in the muscular elements of the 

 heart and at the same time an increase in the vascular tone, which in its turn 

 again increases the work of the heart. — Grawitz and Israel, also Lewinski, pro- 

 duced an artificial chronic indurative nephritis in dogs and rabbits by temporary 

 ligation of the renal artery, and this was later followed by a hjrpertrophy of the 

 heart. 



Palpation sometimes shows enlargement, more frequently 

 increased consistency, but occasionally a diminution and irreg- 

 ular contour of the kidneys. 



The respiration becomes sometimes, especially in dogs, 

 increasingly difficult in the further course of the disease and 

 ultimately asthma may actually develop (Lienaux). 



When the disease is severe, cardiac weakness eventually 

 follows, manifested in pounding heart beat with feeble and 

 rapid pulse, also in dropsical effusions; the amount of urine 

 is then diminished, the specific gravity increased. At this stage 

 emaciation progresses rapidly and finally the animals die of 

 .exhaustion, of pulmonary or laryngeal edema, possibly of in- 

 testinal hemorrhage or hemorrhagic enteritis. (Thomas ob- 

 served epistaxis in a cow.) 



The symptoms of uremia may appear in every stage of 

 the disease. They usually correspond more to chronic uremia 

 (disturbed appetite, vomiting, occasionally diarrhea, eventually 

 epileptoid or asthmatic attacks) and often appear in repeated 

 paroxysms. Occasionally an acute uremic attack closes the 

 scene. 



Course. The duration of the disease is always protracted. 

 If it is recognized by urinary examination after the appearance 



