1. Two cases of bovine cerebral theileriosis in the Union of South Africa
due to Theileria mutans are described.
2. Clinically the animals exhibited a staggering and swaying gait, prostration,
struggling and galloping movements, frothing at the mouth, and a subnormal
3. Macroscopically the brain showed focal yellow discoloration, hyperaemia
and thickening of the meninges, and haemorrhagic infiltration of the dorsal region
of the cerebrum and cerebellum.
4. Microscopically a lymphocytic leptomeningitis, perivascular encephalitis,
focal demyelinisation, glial proliferation, thrombosis of the blood vessels and
Koch bodies in the lymphoid cells were present.
5. This disease bears marked similarity to turning sickness due to
Theileria parva described in East Africa and presumably due to Theileria mutans
described in West Africa.