pica and Monkey-Diseases

Parasite levels were determined for 141 members of a naturally formed social group of rhesus macaques living under free-ranging conditions. Results indicate that group members harbor Trichuris trichiura, Balantidium coli, and large numbers of Strongyloides fuelleborni. Parasite counts decrease significantly with age in this population. Females have significantly fewer parasites than males and a significantly lower prevalence of multiple infections. There were no rank effects regarding parasitosis. While 89% of the animals examined are infected with one or more species of enteric parasite, the prevalence of diarrhea is negligible (2%). The low prevalence of diarrhea in the presence of high parasite loads may be due to the practice of geophagy, which is engaged in by 76% of group members. Soil eaten by these monkeys contains large amounts of kaolinitic clays. Kaolin-based pharmaceuticals (i.e. Kaopectate) are commonly used in human populations to treat diarrhea and intestinal upsets. The mechanical and pharmaceutical properties of the natural kaolinite-based clays may counteract the effects of parasitosis in this free-ranging population.

Topics: Animals; Balantidiasis; Balantidium; Diarrhea; Feeding Behavior; Female; Intestinal Diseases, Parasitic; Kaolin; Macaca mulatta; Male; Monkey Diseases; Pica; Prevalence; Soil; Strongyloides; Strongyloidiasis; Trichuriasis; Trichuris

Hair pulling and eating has not yet received attention in the nonhuman primate literature. Hair pulling and eating was recorded 388 times in two heterogeneous troops of healthy rhesus monkeys that were kept according to modern management practices. The behavior in question consists of the following sequence: pulling with the fingers (1/3 of cases) or with the teeth (2/3 of cases) tufts of hair from one's own or from a partner's coat; chewing the hair and finally swallowing it; the undigested material is excreted in the feces. Hair pulling was almost exclusively (378/388) partner-directed. It was observed 364 times between animals whose dominance relationships were known; it was performed in 96% (349/364) of observations by a dominant but only in 4% (15/364) of observations by a subordinate monkey. The recipient of hair pulling showed typical fear and/or avoidance reactions. In both troops young animals (2-8 years of age) engaged in hair pulling and eating significantly more often than old animals (10-26 years of age). There was no evidence that nutritional, toxicological or climatic factors were responsible for the manifestation of this behavior. It was concluded that, similar to trichotillomania in man, wool pulling and eating in sheep and muskox, and feather picking in poultry, hair pulling and eating is an aggressive behavioral disorder in rhesus monkeys reflecting adjustment problems to a stressful environment.

Topics: Animals; Dominance-Subordination; Female; Macaca; Macaca mulatta; Male; Monkey Diseases; Obsessive-Compulsive Disorder; Pica; Social Behavior; Social Dominance; Trichotillomania