1.an often fatal disease caused by trypanosome protozoan parasites that affects hoofed animals such as cattle, horses, and goats in tropical Africa and is transmitted by the tsetse fly.
1.In cattle the disease is called Nagana, a Zulu word meaning "to be depressed" .
在牛群中，该病称为那加那病，祖鲁语的意思是“抑郁”。