Abstract
Faecal samples and blood films from 3 species of Old-World monkeys, Macaca mulatta, Macaca irus and Papio dogeura, were examined for the presence of nematode parasites. 8 separate groups, a total of 200 animals, were examined within 24 hours of their arrival at the premises of a primate importer. 8 species of nematode were found to be common inhabitants of the alimentary tract, and small numbers of microfilaria were detected in all groups.