Etiology. Anatomical Changes. 555 



the lungs. Altliougli in these cases ascites is the result of passive 

 congestion of the venous system throughout the body, or at least 

 in the hind quarters, it very often remains the only symptom for 

 a long time, especially in dogs. 



Ascites and other symptoms of dropsy are often seen in 

 animals that are cachectic. A similar form of the disease is 

 seen in cases of chronic nephritis, liver rot, parasitic pneumonia 

 and gastritis, or in cases where substances rich in water figure 

 largely in the diet (turnips). 



In young animals, and especially in young dogs, uncompli- 

 cated cases of ascites apparently occur* The fact that such 

 cases often recover completely, suggests the uncomplicated na- 

 ture of the condition. 



According to Hamburger this is a specific condition caused by an organism 

 named by him the "Bacterium lymphagogon" and which increases the quantity of 

 lymph through the action of its metabolic products. 



Anatomical Changes. In the horse there may be as much 

 as 170 liters of liquid in the peritoneum (Brusasco) and in the 

 dog twenty liters (Hordt). The liquid is sometimes clear as 

 water and in other cases slightly turbid. It may be faintly yel- 

 low in color, watery, and contains at most only traces of 

 fibrin. The specific gravity is below 1,016, but, as a rule, very 

 nearly that; it contains 3.5 per cent of albumin and its chem- 

 ical reaction is either alkaline or neutral. The fluid is often 

 opalescent. By transmitted light it may have a yellowish tint 

 and by reflected light a greenish color. This is probably due to 

 the presence of blood pigment. When the transudation is due 

 to a rise of pressure in the portal system the liquid may be from 

 reddish to blood red in color. In cases of jaundice it'is green- 

 ish and bile pigments can be demonstrated in it. There is, as 

 a rule, only a small amount of sediment composed of a few white 

 blood corpuscles, desquamated endothelial cells infiltrated with 

 fat, granular debris, threads of fibrin, and not rarely a few red 

 blood corpuscles. In some cases the latter are present in large 

 numbers (Fig. 73). 



The peritoneum appears in some cases smooth and glisten- 

 ing, but where the disease has been in existence for a long time 

 it is thickened and shows adhesions at places. The abdominal 

 viscera appear anemic and even atrophied. In many cases the 

 postmortem examination is completed by the discovery of some 

 primary condition. 



In cats and dogs the transudate is sometimes comparatively rich in fat 

 (Ascites adiposus or chyliformis) and appears gray or milk white. The linuid 

 may be translucent or quite opaque and when allowed to stand a thick layer of fat 

 may form on the surface. The fat droplets are derived from desquamate.l en<lothelial 

 cells that have undergone fatty degeneration or from the cells of neoplasms (cancer 

 epitheboma), or directly from the bloo.l in cases of lipemia. Wohlmuth found white 

 colored serum in the peritoneal cavity of a fowl. 



In many cases the fluid resembles lymph (ascites chylosus). Cases of this 

 kind have lieen observed in cats by Dollar, Cray, Marcone. Wohlmuth and Ruff ran 

 and one ease m the dog by Johne. The lymph may be derived from a ruptured 



