Trauma rates and patterns in specific pathogen free (SPF) rhesus macaque (Macaca mulatta) groups.

There are some predictable patterns of trauma in captive rhesus macaque (Macaca mulatta) social groups. Several factors have been documented to contribute to these patterns, including group formation of unrelated animals, and the establishment of dominance ranks. Here, we report on how socially induced trauma in groups of rhesus monkeys is influenced by the breeding season, numbers of matrilines per group and matriline size. We analyzed 3 years of data collected from veterinary admittance logs for four groups in our specific pathogen free (SPF) breeding colony. Since the groups differed in time from formation, both the numbers of matrilines and the composition of those matrilines were different. Across the four groups, trauma rates were significantly higher during the fall breeding season than the spring and summer months when births occur. The group that was formed most recently, comprised of the greatest number of matrilines but fewest related animals, showed significantly higher rates of trauma than the older social groups. Further, the middle and lowest ranking families received signifincantly higher rates of trauma than the highest ranking families, suggesting a rank-related phenomenon. Additionally, there was a significant negative correlation between numbers of adult females in a matriline and rates of trauma observed in each matriline, but the numbers of adult females are significantly higher in the top ranked families compared to all of the other matrilines. These findings suggest that trauma rates increase during the breeding season and may be exacerbated in recently formed breeding groups that have smaller matrilines and reduced opportunities for social support to mitigate rank-related aggression. Management practices should be devised to ensure adequate matrilineal size to decrease rates of trauma in captive rhesus macaque groups.

Accuracy of Human and Veterinary Point-of-Care Glucometers for Use in Rhesus Macaques (Macaca mulatta), Sooty Mangabeys (Cercocebus atys), and Chimpanzees (Pan troglodytes).

Handheld, point-of-care glucometers are commonly used in NHP for clinical and research purposes, but whether these devices are appropriate for use in NHP is unknown. Other animal studies indicate that glucometers should be species-specific, given differences in glucose distribution between RBC and plasma; in addition, Hct and sampling site (venous compared with capillary) influence glucometer readings. Therefore, we compared the accuracy of 2 human and 2 veterinary glucometers at various Hct ranges in rhesus macaques (Macaca mulatta), sooty mangabeys (Cercocebus atys), and chimpanzees (Pan troglodytes) with that of standard laboratory glucose analysis. Subsequent analyses assessed the effect of hypoglycemia, hyperglycemia, and sampling site on glucometer accuracy. The veterinary glucometers overestimated blood glucose (BG) values in all species by 26 to 75 mg/dL. The mean difference between the human glucometers and the laboratory analyzer was 7 mg/dL or less in all species. The human glucometers overestimated BG in hypoglycemic mangabeys by 4 mg/dL and underestimated BG in hyperglycemic mangabeys by 11 mg/dL; similar patterns occurred in rhesus macaques. Hct did not affect glucometer accuracy, but all samples were within the range at which glucometers generally are accurate in humans. BG values were significantly lower in venous than capillary samples. The current findings show that veterinary glucometers intended for companion-animal species are inappropriate for use in the studied NHP species, whereas the human glucometers showed clinically acceptable accuracy in all 3 species. Finally, potential differences between venous and capillary BG values should be considered when comparing and evaluating results.

Spontaneous leiomyomas of the gastroesophageal junction in a chimpanzee (Pan troglodytes).

A 49-y-old, female chimpanzee presented with a history of cardiac failure. Postmortem examination revealed lesions consistent with congestive heart failure and 2 incidental, round, firm, pale-tan intramural nodules (diameter, 2 cm) in the stomach at the gastroesophageal junction (GEJ). Histologically, the GEJ nodules were diagnosed as benign spindle-cell tumors. Immunohistochemical evaluation revealed neoplastic cells diffusely labeled with α-smooth muscle actin and vimentin, multifocally labeled for desmin, and were negative for c-kit (CD117). Electron microscopy revealed intracytoplasmic bundles of myofilaments with dense bodies, basal lamina, and few pinocytic vesicles in the neoplastic cells. According to these findings, leiomyomas of the GEJ were diagnosed. Gastrointestinal stromal tumors have been documented to occur in chimpanzees, but there are no reports of GEJ leiomyomas. To our knowledge, this report is the first description of spontaneous leiomyomas of the GEJ in a chimpanzee.