It may also be differentiated from the former by the history of a recent parturition or surgical operation, by the presence of an external injury at the site of the swelling accompanied with a fetid liquid discharge, and the gangrenous appearance of the tumefaction.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
A microscopic examination of the juices from the tumefaction will show the blackleg bacillus.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
The superficial form presents itself first as a doughy tumefaction of the skin about the region of the throat, neck, dewlap, or legs, which pits on pressure.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler