They usually begin with the appearance of very minute tubercles.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
Other organs, such as the liver, not infrequently contain tubercles.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
The disease is thus a development of these tubercles in one or more organs of the body.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler