Environmental and host determinants of acute gastric dilatation in nonhuman primates: a retrospective cohort study

Acute gastric dilatation (AGD) has been occasionally reported as a clinically important condition in laboratory non-human primates, with potentially fatal outcomes. However, the environmental and host-related factors contributing to AGD occurrence remain poorly understood. In this study, we investigated AGD cases identified at two independent primate centers in Republic of Korea and assessed their associations with environmental and host-related factors. In univariable analyses, housing type, facility location, and sex were significantly associated with AGD occurrence. In the exploratory multivariable Firth analysis, a statistically significant association was observed only for housing type; however, the independent contribution of each factor could not be clearly determined because of the small number of AGD cases and substantial confounding among these variables. AGD-affected animals may exhibit stress-associated leukocyte changes, characterized mainly by eosinopenia, mild lymphopenic tendencies, and monocytosis in a subset of animals. In the blood chemistry analysis, alanine aminotransferase showed an overall upward distribution and serum creatinine values tended to be lower. In conclusion, the findings suggest a potential association between individual housing and AGD occurrence, while stress-related physiological changes and reduced locomotor activity may represent plausible hypotheses underlying this association, although these mechanisms were not directly assessed in the present study.