Proliferative enteritis associated with Lawsonia intracellularis in a Japanese macaque (Macaca fuscata)

Area of Science:

• Veterinary Pathology
• Primate Medicine
• Microbiology

Background:

• Proliferative enteritis is a significant gastrointestinal disease in various animal species.
• Lawsonia intracellularis is an emerging intracellular bacterium affecting the gut lining.
• Nonhuman primates are important models for human diseases, necessitating understanding of their unique pathogens.

Observation:

• A 2.5-year-old male Japanese macaque presented with a thickened ileum during exploratory surgery.
• Clinical signs included transient diarrhea and severe hypoproteinemia post-operatively.
• Diagnostic investigations involved histopathology, immunohistochemistry, and PCR analysis of ileal tissue.

Findings:

• Lawsonia intracellularis-associated proliferative enteritis was confirmed as the cause of the ileal thickening.
• The macaque recovered following treatment with azithromycin.
• Specific diagnostic methods are crucial for identifying Lawsonia intracellularis.

Implications:

• This case highlights the potential for Lawsonia intracellularis infection in Japanese macaques.
• The need for specialized diagnostic techniques may lead to underdiagnosis in nonhuman primate populations.
• Further research is warranted to understand the prevalence and impact of proliferative enteritis in captive and wild primates.