Survey of parasites of rhesus monkeys housed in small social groups

A survey of specific parasites in fecal samples randomly collected from socially housed rhesus monkeys was done over a 1‐year period. Differences in frequency of samples with parasites, and number of different species per sample, were assessed by social group composition, social group size, female reproductive status, and season of the year. Common parasites were Entamoeba coli, Iodamoeba bütschlii, Balantidium coli, Strongyloides fülleborni , and Trichuris trichiura . Samples from juvenile/subadult groups had more species of potentially pathogenic parasites per sample but fewer species of nonpathogenic parasites per sample than samples from adult groups. When group size reached 12 to 16 animals, the number of samples with helminths doubled. Samples collected from groups with gestating/ lactating females had more species of nonpathogenic parasites than samples collected from groups with cycling or noncycling females. Fewer samples collected in the spring had helminths than samples collected during the fall, winter, and summer. The number of potentially pathogenic species present per sample was highest during the summer. Following anthelminthic treatment, the number of helminthic species present per sample and the number of samples with helminths remained low, then began increasing after 2 to 3 months. The number of potentially pathogenic species per sample decreased while animals were fed an inadvertently vitamin C deficient chow. © 1992 Wiley‐Liss, Inc.