Symptoms. 37 



discharged which contains gas bubbles. In some cases the skin 

 over the swelling acquires a dark color, and may finally become 

 extensively necrotic. 



In cases where the swelling develops in association with 

 an evident injury the wound takes on a bright color and a 

 peculiar lustre, and a dirty red, fetid, serous fluid oozes from 

 its surface. Later the margins of the wound become necrotic 

 in portions. 



If the infection occurs through the genital passage during 

 or shortly after parturition the first manifestation of the disease 

 appears after 2 to 5 days. The vulva swells in the form of 

 a cushion, and a dirty, brownish-red, very fetid, thick secretion 

 is discharged from the vagina. Soon a crepitating swelling de- 

 velops in the surrounding parts of the external genitals which 

 is at first warm and painful but later cool and painless, and 

 gradually extends over the perineal region and the lower abdo- 

 men. Besides high fever, bloating and diarrhea are observed. 



Malignant edema developing in association with parturition in cat- 

 tle is frequently mistaken for blackleg. Recently Alrert & Carl estab- 

 lished with a certain degree of probability that the cases described as 

 parturition blackleg are actually malignant edema, and that blackleg 

 never develops in this form. 



Following castration the first symptoms appear after a 

 few days or sometimes after several weeks; aside from high 

 fever, an extensive edema develops under the skin of the abdo- 

 men, emanating from the castration wound, and later shows 

 crepitation on palpation. In addition the animal manifests 

 colicky pains, sensitiveness over the abdominal wall and bloat- 

 ing; in other words, there are indications of peritonitis, and 

 finally signs of a general infection and exhaustion. 



Of the other symptoms of the disease the markedly diffi- 

 cult respiration, the cyanotic mucous membranes, the accelerated 

 and weak heart action, and the corresponding small, wavy pulse 

 are conspicuous. The body temperature reaches a high degree 

 even at the onset of the disease, remains at a uniform height, 

 but as death approaches it drops to normal or subnormal. In 

 later stages of the disease diarrhea is very frequently observed 

 in which fetid and watery feces are discharged. 



The symptoms follow each other rapidly; the crepitating 

 swelling increases in size from hour to hour, and death usually 

 occurs in twelve hours to three days after the appearance of 

 the' first symptom. In some of the cases, however, the disease 

 terminates in recovery, especially after appropriate treatment. 



Livesey observed the disease in a dog. On the left side of the head 

 an emphysematous swelling developed and progressed to the neck and 

 shoulders. At the same time the lips and cheeks became necrotic. 

 Pankul demonstrated the disease in hogs; a crepitating swelling devel- 

 oped in this instance from a wound in the skin. 



