Listeria monocytogenes septicemia and fetal maceration in long-tailed chinchillas (Chinchilla laniger) in Argentina.

Listeria monocytogenes is a zoonotic bacterium widely distributed in the environment and capable of infecting a broad range of animal species, including humans, usually as a food-borne disease. Although listeriosis is well recognized across multiple hosts, information in small mammals such as rodents and lagomorphs remains comparatively limited, with most reports describing sporadic systemic disease. This study describes two cases of septicemic listeriosis with reproductive involvement in pregnant long-tailed chinchillas (Chinchilla laniger) from a breeding facility in Argentina. Both animals developed depression, anorexia, prolonged gestation, and died. Grossly, both animals had mucosanguineous vaginal discharge and fetal maceration; one also showed multifocal random hepatic necrosis. Histopathology revealed severe multifocal necrosuppurative hepatitis, enteritis, endometritis and placentitis, and pulmonary thromboembolism. Immunohistochemistry demonstrated abundant intralesional Listeria spp. antigen in the liver and uterus. L. monocytogenes DNA was detected in the liver by real-time PCR. The present work expands the knowledge of listeriosis in chinchillas by providing detailed documentation of systemic infection with reproductive involvement. Given the zoonotic nature of L. monocytogenes, early recognition of infection in captive animal populations is relevant for both animal and public health.