36 Malignant Edema. 



swollen and covered with a dirty, pasty, ill smelling mass which 

 also covers the cotyledons that are in the process of breaking 

 down (Carl). 



The spleen as a rule appears normal in size or slightly 

 swollen. Exceptionally, however, an acute swelling of this 

 organ with gas formation in the pulp has been observed 

 (Frohner). The liver shows cloudy swelling and the intestinal 

 mucous membrane shows indications of an acute catarrh. The 

 IjTiiph glands are acutely swollen, while the lungs manifest well 

 marked active hyperemia and also edema (which, according to 

 Kitt, are occasionally the only lesions found in sheep) ; the heart 

 muscle usually shows marked parenchymatous degeneration. 

 The blood is slightly coagulated, and the carcass decomposes 

 rapidly. 



In the fluid squeezed out from the crepitating swellings or 

 taken from the cut surface, or frequently in the abdominal 

 fluid, edema bacilli may be found in large numbers even in the 

 unstained miscroscopical preparations. The bacilli, which not 

 infrequently contain spores, occur singly, in chains or as curved 

 threads, and are often found in association with other bacteria. 

 Several hours after death the bacilli are found in the blood, 

 particularly the blood of the lungs where they often occur in 

 long threads similar to those seen on the peritoneum. 



The presence of the bacilli of malignant edema is not in itself 

 proof that the particular animal died from this disease. These bacilli 

 occur frequently in association with other bacilli in the intestinal con- 

 tents of herbivorous animals, and from there they may spread after the 

 death of the animal throughout the body even to its most distant parts. 

 This is particularly the case when the blood remains fluid, as for in- 

 stance, in a suddenly appearing asphyxiation, and thus promotes their 

 m.ultiplication and dissemination. From the intestines the organisms 

 first enter the peritoneum, next the blood vessels of the intestines and 

 mesenteries, and then the portal vein from whence they may be dis- 

 seminated throughout the blood. 



Symptoms. After infection an edematous swelling, which 

 is not sharply circumscribed, may develop in 12 to 24 hours in 

 any part of the body. The swelling is at first tense, warm, 

 very painful, later cooler, soft, doughy and less sensitive, and 

 may even become entirely insensitive in the center, so that 

 the animal does not manifest pain when incisions are made 

 into the swelling (at the borders, however, it shows the charac- 

 teristics mentioned). At the same time the swelling reveals 

 crepitation on palpation. The swelling usually develops at 

 places where considerable loose connective tissue occurs under 

 the skin; by spreading over the surface it may occasionally 

 involve the entire side of the body, anteriorly to the neck, 

 posteriorly to the upper parts of the extremities, resulting in 

 difficult and painful movements of the body. Upon incision a 

 reddish-yellow, reddish-brown, or a colorless serous fluid is 



