Sudden death caused by Aeromonas hydrophila in a Crab-eating Macaque (Macaca fascicularis) associated with captivity stress

• Published in: Journal of Veterinary Medical Science Vol. 85; no. 4; pp. 22-0473 - 531
• Main Authors: SEO, Min-Goo, KIM, Kyoo-Tae
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 2023; Japan Science and Technology Agency; The Japanese Society of Veterinary Science
• Subjects: Adrenal glands; Aeromonas hydrophila; Animals; Anorexia; Captivity; cortisol; crab-eating macaque; Death, Sudden - etiology; Death, Sudden - veterinary; Duodenum; Emphysema; Enlargement; Female; Gram-negative bacteria; Gram-Negative Bacterial Infections - microbiology; Gram-Negative Bacterial Infections - veterinary; Immune system; Inflammation; Kidneys; Macaca fascicularis; Opportunist infection; Sternum; stress; Wildlife Science; zoo; Aeromonas hydrophila; cortisol; stress; crab-eating macaque; zoo
• ISSN: 0916-7250; 1347-7439
• DOI: 10.1292/jvms.22-0473

Aeromonas hydrophila is a facultative anaerobic gram-negative bacterium regarded as an opportunistic pathogen in animals. A 17-year-old female crab-eating macaque (Macaca fascicularis) died after experiencing anorexia and depression for several days. The carcass was severely emaciated, and the sternum was exposed under subcutaneous lesions in the thorax. Many abnormal pathological lesions were found, including tracheal inflammation, pulmonary inflammatory emphysema, yellowish discoloration of the liver, enlargement of the gall bladder, necrosis of the heart, congested bilateral kidneys, and enlargement of the adrenal glands. The stomach was empty, mucosal ulcerations were found, and the duodenum was congested. Giemsa staining revealed rod-shaped organisms in the whole blood smear and major organs, which were identified as A. hydrophila. The animal had experienced stress, and decreased immune system function possibly contributed to the infection.