162 Pyo-Septicemia of Sucklings. 



Small particles of the softened thrombus may be carried off. 

 by the circulating blood, a;nd with these the bacteria may entei: 

 the free blood circulation. They are taken either into the liver 

 or with tlie blood of the vena cava into the general circulation. 



The micro-organisms which enter the umbilical vein from 

 without do. not necessarily remain confined in the immediate ' 

 surroundings of the umbilical ring. While the circulation 

 ceases after birth in this blood vessel, the passing blood stream 

 of the portal vein or of the ductus Arantii, as well as the ■ 

 respiratory movements, produce a suction on the fluid which 

 is present in the umbilical vein, by which the blood serum 

 separates from the blood coagulum, is diverted toward the' 

 portal vessel, carrying with it the micro-organisms which may 

 be contained therein. They may remain attached to any part 

 of the intima of the umbilical vein, where they produce a local 

 inflammation as a result of which deposits of blood coaguluttf " 

 occur, or a softening of the thrombus which is already present.^ 

 The bacilli may even penetrate thfe portal vein without stopping,* 

 whence the blood Conveys them into the heart. In the first' 

 case that section of the umbilical vein which is nearest to 

 the umbilical ring remains healthy ; in the other case the entire 

 umbilical vein will be intact although the infection has passed 

 through it. 



In ruminants the infective agent enters with the blood 

 either through the ductus Arantii or through the ramification 

 of the portal and hepatic veins into the vena cava, and 

 thence into the general circulation. In foals all septic material 

 enters through the latter channels. In these animals, however, 

 breaking down of the blood coagulum is also frequently 

 observed in the umbilical arteries (Gmelin), as a result of which 

 the infective agent may pass into the posterior part of the 

 abdominal aorta; and with the blood of these vessels into the 

 peripheral arterial ramifications of the posterior extremities. 



Certain organs appear to have a special predisposition for 

 attacks by the micro-organisms circulating in the blood. Of 

 these the lungs and the liver should be mentioned first, and in 

 addition metastatic inflammations develop frequently on the 

 synovial membranes of certain joints. 



In acute cases of the disease the flooding of the blood with 

 pathogenic bacteria, as well as the inflammatory processes which 

 develop at different parts of the body, cause the death of the 

 animal. In some cases, however, the acute affection is suddenly 

 checked, and the disease process appears to turn towards 

 recovery. After several weeks, or in one to two months, how- 

 ever, manifestations of the chronic affection, especially of the 

 lungs, make their appearance. These manifestations may be 

 associated with the pre-existing infection. According to Nocard ' 

 bacteria of hemorrhagic septicemia may disappear after a time 

 from the blood; the toxins, however, have in the meantime 

 exerted a paralytic action on the cells by which the resistance of 



