CHAPTER XIV 



MALIGNANT EDEMA 



History. This is a rare disease and it is impossible to secure any 

 exact information concerning its prevalence in past ages. In 1877 

 Pasteur introduced bits of putrid flesh under the skin of guinea-pigs 

 and rabbits, and thus induced a rapidly progressive disease character- 

 ized by the accumulation of fluid in the subcutaneous tissue. He was 

 able to transfer the disease from one animal to another and found 

 that it was due to a rod-shaped, spore-bearing organism which he 

 designated as Vibrion septique. In 1881 Koch continued this work 

 and since that time the disease has been known as malignant edema. 



The Bacillus. It is still a question whether there is only one or 

 several closely related organisms capable of inducing this pathologic 

 condition. Even when the same strain is employed in experimental 

 inoculation, the effects are not always exactly the same. The fluid 

 which collects in the subcutaneous tissue may be only slightly, or 

 markedly, bloody and the infiltration may be accompanied by the 

 evolution of more or less gas. The typical bacillus is a rod with 

 rounded ends, slightly motile, growing in the absence of air, and 

 developing spores. It liquefies gelatin and blood serum, coagulates 

 milk and then digests the coagulum. It produces abundant gas in 

 media containing glucose and traces of gas in media practically 

 free from carbohydrates. Horses, cattle, hogs, and sheep are sus- 

 ceptible, but infection probably never occurs except through a wound 

 either on the skin or the mucous membrane. It is one of the sequelae 

 of castration in males and of birth in females among our domestic 

 animals, although even in these conditions it is quite rare. When 

 infected matter is taken into the alimentary canal it passes through 

 without doing harm unless there be some break in the mucous mem- 

 brane. When it infects man and the larger animals, the bacillus is 

 found abundantly in the edematous fluid, but seldom widely dis- 

 tributed through the body. This indicates that it kills by the elabora- 



