Animal trypanosomiasis, or nagana, is a devastating disease that affects livestock in sub-Saharan Africa, particularly cattle. This parasite-borne disease is transmitted by the tsetse fly and is caused by several species of the protozoan Trypanosoma. Synonyms for animal trypanosomiasis include African animal trypanosomiasis, African sleeping sickness, and tsetse fly disease. These terms help to describe the geographic and vector-specific nature of the disease. While trypanosomiasis can also affect humans, the term African sleeping sickness typically refers to the human form of the disease caused by Trypanosoma brucei. Understanding the many names for trypanosomiasis is crucial for monitoring and treating this debilitating disease.