GENERAL PART OF EXAMINATION. 47 



dominal cavity. In the ox urethral calculi commonly cause 

 this condition. 



V. Swellings in, and immediately under, the skin. 

 Diffuse or multiple swellings appearing in or immediately 

 under the skin are of great importance as an aid to the diag- 

 nosis of internal diseases which they accompany. 



Tumefactions of the skin attend the following morbid 

 processes : 



Edema of the skin and subcutis (anasarca) 

 is an abnormal accumulation of serum in the connective tissue. 

 It is produced by a transudation of fluid (liquor sanguinis) 

 from the blood into the intercellular spaces. The lymph 

 spaces being clogged prevents the escape of the fluid. Ede- 

 matous swelling are doughy on palpation and retain finger im- 

 prints. 



Edema can be due to : 



a. Continued venous congestion, the free circulation of 

 the blood being interrupted (dropsy from stasis). In such 

 cases a dropsical swelling appears in pendent portions of the 

 body, removed from the heart. The prepuce, in front of the 

 mammae, ventrally along the abdomen and thorax, hind limbs, 

 brisket and throat are the favorite seats of these enlarge- 

 ments which are neither painful nor hot. Any morbid condi- 

 tion which interferes with the free flow of the blood through 

 the veins, leading to a stagnation in these vessels, tends always 

 to produce edematous swellings. They attend organic heart 

 troubles, chronic pleuritis, pericarditis, and traumatic peri- 

 carditis of the ox. 



b. A watery condition of the blood (hydremia) with 

 which occurs an abnormal porosity of the blood vessels, and a 

 subsequent transudation into the tissues. The edema of 

 hydremia shows neither increased warmth nor pain. Drop- 

 sies due to hydremia are noted under the jaws of sheep 

 afflicted with animal parasites, [the lung and stomach worms, 

 Str. contortus, Str. filaria; liver flukes. Dist. hcpaticum, being 



