Experimental trypanosomiasis in Yankasa ewes: the body weight response

Sleeping sickness (African Trypanosomasis) is an anthropozoonosis transmitted primarily by the tsetse fly. It is associated with a host of clinical indices ranging from fever, aneamia and anorexia to reproductive failures in man and his domestic animals. The main objective of this study is to appraise the responsiveness of the body weight as a clinical indicator of sleeping sickness in experimentally infected Yankasa ewes. Twelve mature Yankasa sheep (6 infected and 6 control ewes) were used in this study. Weekly body weights and daily rectal temperature were taken while blood samples for haematology were collected twice a week from all animals before and after the experimental infection. Undulating parasitaemia was observed, two days post infection and was sustained through out the study period of about fifty days in all the infected ewes. Decreased body weight was found to be very prominent in the infected animals. All the infected ewes progressively lost weight during the experiment with a decrease of about 17.9% of the original weights while the control ewes had increased by 4.2% at the end of the study period. The body weight is therefore a very sensitive parameter in the surveillance and management of Trypanosome infections especially in Yankasa ewes as experimental animal models.