Abstract:
A detailed description of the histopathology of the nervous system and a brief account of lesions in
visceral and other organs of six horses experimentally infected with Trypanosoma brucei Plimmer & Bradford, 1899 is given.
Attempts to produce a chronic form of nagana in three horses by subcurative medications with
Antrypol and Berenil were successful. The chronicity period was extended to 130 days in one and to
approximately 9 months in the other two horses. The data on the histological findings on the three
horses are listed in tabular form. The lesions in the central nervous system were characterized by a severe
pleocytosis of the meninges, an extensive subpial gliosis corresponding in severity to the involvement of
the overlying leptomeninges, segmental demyelination of optic tracts and some other areas of white
matter as well as grey matter and extensive perivascular cuffing with lymphocytes, plasmocytes, large
mononuclear and Mott cells in this order of descending frequency.
Comparison between lesions of the acute form of human sleeping sickness and those of the experimentally
produced chronic form of equine nagana revealed that points of similarity are far greater than
those of dissimilarity. The latter include a lymphophagocytosis in the meninges and brain of man, a
higher incidence of Mott cells in the meninges of horses and the penetration of trypanosomes in the
brain of man which was not seen at this site in horses.
With the exception of the pituitary of one horse, lesions of the nervous system of the remaining three
horses were not striking. Histological changes in the visceral and other organs were neither pathognomonic
nor of uniform occurrence.
