Stanton B. Gray

Abstract Chronic enterocolitis (CE) is a disease of significant concern in colony-housed rhesus macaques, leading to chronic diarrhea and severe weight loss necessitating euthanasia in up to 25% of adults. Despite over three decades of research into this syndrome, mitigating strategies have been met with variable success and chronic diarrhea remains an ongoing problem in research colonies.

Rhesus macaques (Macaca mulatta) are a critical resource in biomedical research across numerous fields, and more recently, cynomolgus macaques (Macaca fascicularis) and rhesus macaques have experienced increased demand due to COVID-19 research.8,29 However, up to 25% of colony-housed rhesus macaques develop a syndrome of chronic intestinal inflammation resulting in chronic diarrhea, weight loss or poor weight gain, and unthriftiness, which severely limits an individual’s value as a research...