MALIGNANT EDEMA 311 



cyanotic mucous membranes, and rapid, weak, irregular 

 pulse. The temperatm-e is elevated early and does not sink 

 to normal until the patient becomes moribund. 



In cows infected during obstetrical manipulations, in two 

 to foiu- days the lips of the vulva begin to swell, the swelHng 

 rapidly involving the perineum, thighs and udder. There is 

 an offensive, brownish discharge from the vagina. The tem- 

 perature is up and bloating and diarrhea noted. 



Diagnosis. — ^The cardinal symptoms of malignant edema 

 are: Rapid development, emphysematous character of the 

 swellings, high fever, and fatal course. It resembles black- 

 leg in cattle, but may be distinguished from this disease by 

 the following: Malignant edema usually affects the repro- 

 ductive organs of cows at the time of parturition; it affects 

 connective tissue rather than muscle, is not confined to young 

 cattle, and appears in districts free from blackleg. Blackleg 

 is common in the United States, and occurs enzootically, 

 while malignant edema is rare in cattle and is sporadic. It 

 would hardly be confused with phlegmons resulting from pus 

 infection. Such swellings do not develop so rapidly, do not 

 crepitate, and are not usually fatal. Ordinary emphysemas 

 of the skin, which accompany rib-fracture, pulmonary emphy- 

 sema, or wounds (median nem-ectomy, trocaring, intentional 

 inflation of the scapular region to conceal musculai atrophies), 

 are not attended by fever and comparatively benign in course. 

 The postmortal emphysema noted in parenchymatous organs 

 in delayed necropsies diu-ing hot weather would hardly 

 mislead a careful observer. 



Course and Prognosis. — ^The course of malignant edema is 

 usually rapid, death resulting from pulmonary edema in 

 twenty-four to sixty hours. The prognosis is bad, 95 per 

 cent, of the cases die. Recovery can be expected only in mild 

 infections and when proper treatment has been prompt. 



Treatment. — ^The treatment is surgical, and consists in 

 slitting the swellings long and deep to allow oxygen to enter 

 the tissue. A thorough disinfection of the incisions should 

 follow while subcutaneous injections of iodin tincture may be 

 made in the neighborhood of the swellings. Hot applications 

 should be avoided. 



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