Yersinia infection in two captive guereza colobus monkeys (Colobus guereza)

Yersinia pseudotuberculosis in Non-Domesticated Mammals and Birds in Captivity

Yersinia pseudotuberculosis causes yersiniosis in a wide range of mammalian and avian taxa worldwide. This review aims to provide an overview of the current literature on yersiniosis in non-domesticated mammals and birds in captivity. Data on the prevalence of Y. pseudotuberculosis in captive populations are scarce. Transmission is primarily via the fecal-oral route, with wild rodents and birds as primary reservoirs. Predisposing factors to yersiniosis include young age, inclement weather, stress, and genetic factors. Symptoms are often non-specific, with sudden death occurring frequently, particularly in avian species. Gross pathological examination typically reveals multiple white-yellow foci in visceral organs, while histopathology demonstrates necrosis with central bacterial colonies. Ante-mortem diagnosis can be challenging as bacterial culture and isolation from fecal samples are often hindered by intermittent excretion and competition with other gastrointestinal flora. Although killed and subunit vaccine formulations have demonstrated limited protective efficacy, live attenuated strains may hold greater promise for inducing more robust and durable immunity. Y. pseudotuberculosis remains a significant threat to animal health, highlighting the need for faster and more reliable diagnostic techniques and the development of more effective treatment and prophylactic strategies.

Modifying the diets of captive proboscis monkeys in a temperate zoo to reduce weight loss and renal disease

In animal husbandry, diets should help in maintaining a healthy body condition, support reproduction, and promote species-specific longevity. It is recommended to feed folivorous primates kept in zoos a high-fiber diet, i.e., leaves, although satisfying such a requirement is challenging in temperate regions because it is difficult to obtain fresh leaves, especially in autumn and winter. As equally important for their appropriate treatment, it is valuable to provide details of clinical reports of medical problems and pathological findings, although such clinical reports are rather limited. Therefore, in foregut-fermenting proboscis monkeys (Nasalis larvatus), we (1) described the individual clinical reports of renal disease and weight loss at the Yokohama Zoological Gardens in Japan, (2) determined the nutritional profile of the diets supplied to these animals because other potential triggers for their renal disease and weight loss could be excluded, (3) modified the diet regimen to minimize weight loss and the development of hypercalcemia and hypophosphatemia, and (4) assessed the effects of such dietary modification by comparing the body weight and the Ca and P concentrations and the Ca/P ratios in the blood before and after diet modification with a comparison of these measurements between zoo and free-ranging individuals. Based on the nutritional profile of the diets, we concluded that the reported cases of renal failure might be caused by consumption of leaves with a Ca/P ratio far above the appropriate level in autumn and winter. Additionally, the dietary modification of minerals and metabolizable energy achieved certain beneficial effects on zoo-kept proboscis monkeys.

Identification and pathogenicity analysis of Streptococcus equinus FMD1, a beta-hemolytic strain isolated from forest musk deer lung

Streptococcus spp. cause a wide range of diseases in animals and humans. A Streptococcus strain (FMD1) was isolated from forest musk deer lung. To identify the bacterium at the species level and investigate its pathogenicity, whole genome sequencing and experimental infections of mice were performed. The genome had 97.63% average nucleotide identity with the S. equinus strain. Through virulence gene analysis, a beta-hemolysin/cytolysin genome island was found in the FMD1 genome, which contained 12 beta-hemolysin/cytolysin-related genes. Hemolytic reaction and histopathological analysis established the strain’s pathogenicity in mice. This is the first report of a beta-hemolytic S. equinus strain in forest musk deer identified based on phenotypic and genotypic analyzes; this strategy could be useful for analyzing pathogens affecting rare animals.