Experimental infection of the Guyanese zebu with Trypanosoma vivax

The Guyanese strain of Trypanosoma vivax is pathogenic for the local Brahman zebu; the experimental infection of 19 one-year old cattle was followed by a moderate and transitory fever, a drop in packed cell volume (PCV) and a quick and marked weight loss of 10 to 17 kg one month after as compared to the 16 non-infected animals. Other symptoms were associated with the parasitaemia: diarrhoea, swollen haematic glands on the neck and the flank, lachrymation, weakness. Despite a trypanocidal treatment injected one month post-infection, one animal died and the weight losses of others were not compensated for three months later. The particular susceptibility of weaning animals is discussed as well as its implications in the control of trypanosomosis.