288 MALIGNANT EDEMA 



The spleen is usuall}^ not affected. Occasionally acute 

 tumors with gas formation are found in the pulp (Frohner). 

 The liver may show tumefaction. The mucous membrane of 

 the intestinal canal may show signs of acute catarrh. The 

 lymph glands are swollen. The lungs are hyperemic and for 

 the most part edematous. The muscular system of the heart 

 shows usually a high degree of parenchymatous degeneration. 

 The blood clots very little. The body quickly becomes putre- 

 fied. The fluid pressed out of the crepitating tumor con- 

 tains edema bacilli in great number, associated possibly with 

 other bacteria. 



The presence of the bacilli of malignant edema in the 

 tissues of a dead animal does not of itself prove that it died of 

 this disease. These bacilli appear very often in the intestinal 

 contents of animals which feed on plants in company with other 

 bacteria and on that account are able after the death of the 

 animal to multiply in its tissues, especially when the blood re- 

 mains fluid for some time, as for example after a sudden death 

 by suffocation. 



^:; 211. Differential Diagnosis. Malignant edema, if 

 it occurs in cattle, can be easily confused with symptomatic 

 anthrax. As distinguishing malignant edema are the occur- 

 rence of the disease in a region where symptomatic anthrax is 

 not native, further the often very advanced age of the patient, 

 the occasional localization of the tumor on parts of the body 

 poor in muscle, and besides the insignificant affection of the 

 muscular system in comparison to the severe affection of the 

 connective tissue. 



In horses and sheep the development of a crepitating tu- 

 mor with a fever indicates malignant edema. The crepitation 

 distinguishes the disease from anthrax edema as well as from 

 the inflammatory edemas often following wounds and caused 

 by streptococci. In simple subcutaneous emphysema, follow- 

 ing skin or lung wounds, fever rarely occurs. Finally care 

 must be taken that on section a simple emphysema caused by 

 putrefaction is not confused with a crepitating tumor formed 

 during life. 



