910 Diseases of (he Spleen. 



circulation or to the splenic vein (as, for instance, in torsion). 

 The most important swelling of the organ, however, is that 

 which frequently occurs in acute infectious diseases. This form 

 of acute splenic enlargenient is caused partly by the accumula- 

 tion of bacteria in the pulp of the spleen, partly, and to a 

 greater degree, by the increase in the number of lymph cells 

 and the deposition of leucocytes containing bacteria as well 

 as the deposition of disintegrated red blood cells which is 

 quickly followed by an inflammatory process associated with 

 swelling and increase of the cells and swelling of the connective 

 tissue framework. (Splenitis hyperplastica acuta.) 



The most striking pathogenic effect of bacteria and their 

 toxins is observed in anthrax. In this affection the spleen 

 may be enlarged as much as 5 to 10 times the normal size and 

 the swelling may increase so rapidly that the capsule, being 

 subjected to severe tension, sometimes tears. In other diseases 

 the swelling is usually less in degree and it is probably least 

 intense in such cases in which only bacterial toxins circulate 

 in the blood. A marked splenic enlargement is met with in 

 swine erysipelas, in acute glanders, and in acute tuberculosis 

 (partly due to the formation of nodules), in pyemia, hemo- 

 globinemia, in the acute infectious anemia of horses, while the 

 various forms of hemorrhagic septicemia as well as croupous 

 pneumonia are accompanied only by slight swelling, and this 

 is entirely absent in purpura hemorrhagica or in tetanus. 



In living animals, except in ruminants and in fat hogs and 

 dogs, acute swelling of the spleen may as a rule be diagnosed : 

 in horses by rectal exploration ; in smaller animals by abdominal 

 palpation. ' The spleen is found to be enlarged, soft or more 

 or less tense to the touch. A considerable swelling may be 

 recognized by dullness on the left side, which is in horses parallel 

 to the costal arch, in dogs and hogs in the direction of the 

 last two intercostal spaces passing downward from the costal 

 arch and which is 3 or 4 fingers wide. In ruminants the swelling 

 is usually unnoticed because the spleen, covered by the lung, does 

 not protrude beyond the posterior border of the lung even if de- 

 cidedly enlarged. Nevertheless in severe cases careful per- 

 cussion may show a dullness at the border between lung and 

 rumen as was recently observed by Szathmary in a butfalo 

 affected with anthrax. 



Literature. Jaweiu, A'. A., 1900. CLXl, 461. — Leukev, Husszerale, 1907. 65. 

 — Szathmary, A. L., 1909. 525. 



Purulent Inflammation of the Spleen. (Splenitis aposte- 

 matosa.) This occurs after the extension of a similar inflam- 

 mation from neighboring organs or after the lodgement of 

 infected emboli (as, e. g., in strangles, etc.). In a case reported 

 by Arndt the embolus in the spleen came from a suppurating 

 inflammatory focus which had been produced by a rusty needle 



