The following description applies to chronic Trypanosomosis caused by T. congolense or T. vivax in susceptible animals.
The disease becomes apparent about seven to ten days after an infective tsetse bite: body temperature rises and the heart and the respiratory rates increase. From now onwards there is a fluctuating but continuous slow deterioration in health with a steady loss of condition. The animal becomes overtly sick with a variable appetite. Its coat becomes dull and "staring" There may be some diarrhoea in the early stages. The animal becomes anaemic (visible mucous membranes are pale). There is very often an increased secretion of tears (lachrymation). The emaciation is associated with weakness and in the final stages results in inability to stand, severe anaemia and death.
The hyperacute haemorrhagic form of Trypanosomosis caused by T. vivax, normally a chronic disease is characterized by bleeding from natural orifices of the animal body and, at post mortem, haemorrhages are very widespread and extensive. Large haemorrhages are seen in the heart, the pleural cavity, the peritoneum, the diaphragm. The disease progresses rapidly to death that there is no loss of condition.
In small ruminants (sheep and goats) symptoms are similar to those observed in cattle. Sheep and goats infected with T. brucei may show central nervous symptoms (staggering, paralysis, etc.). In sheep infected with T. brucei it may be observed infiltration with liquid of subcutaneous tissues which leads to swelling of the eyelids, the lips and the skin beneath the lower jaw.