Urbanization influences not only free-living organisms, but also various pathogens, including those with limited visibility to humans. Although previous research on urban parasites has primarily focused on human-specific and zoonotic species, a comprehensive understanding of parasite ecology in urban settings requires attention to inconspicuous enzootic species. In this study, we investigated two flea species, Aenigmopsylla grodekovi and Ceratophyllus (Monopsyllus) indages indages, parasitizing Eurasian red squirrels Sciurus vulgaris orientis in and around Obihiro City, Hokkaido, Japan. These fleas, dislodged during the routine handling of host squirrels, were collected and quantified during spring and autumn surveys to assess seasonal and spatial patterns of infestation across urban and rural sites. Over the course of a four-year survey (2017–2020), 317 squirrels (168 males and 149 females) were examined, with 284 individuals of A. grodekovi and 214 of C. (M.) indages indages recovered. The former was rarely observed in spring but showed a pronounced increase in autumn, with rural areas exhibiting 14.06 times more dislodged individuals than urban areas, on average. In contrast, the latter was more prevalent in spring (2.50 times higher than in autumn) and displayed no consistent difference between urban and rural habitats. Our results revealed distinct dislodgement patterns in two flea species in response to habitat and seasonal variations, indicating species-specific responses to urbanization. While direct quantification of flea abundance remains ideal, the number of dislodged individuals may serve as a useful indicator for assessing the effect of urbanization on host-parasitic interactions and infrapopulation dynamics.
In this narrative review, we provide an overview of morphology-based body composition measurement techniques and introduce evaluation methods relevant to veterinary practice. We specifically focus on previous work on the feline body mass index and body composition assessment methods using ultrasonography, creating new figures and tables from previously reported data. Based on these modalities, we introduce an objective, easy-to-use method for estimating obesity and assessing body composition. We highlight that adiposity and muscularity evaluation via the feline body mass index and ultrasonography appropriately reflects the total fat mass, fat percentage, and lean body mass assessed using dual-energy X-ray absorptiometry. The proposed method objectively assesses obesity and can be easily and stably used in clinical veterinary practice.
Welfare-friendly housing systems for laying hens, such as cage-free, have become prevalent. However, the physiological effects of housing systems on the laying hens remain poorly understood. Here, we compared behavioral characteristics and transcriptomic profiles from 90 multi-tissue samples among three housing systems: battery cage (BC), barn (BR), and free-range (FR). BR and FR housing promoted behavioral diversity compared to cages. Transcriptome analysis of central tissues (diencephalon and cerebral hemisphere) and peripheral tissues involved in egg production (liver, ovary, oviductal segments of magnum, and uterine) revealed significant enrichment of insulin resistance-related pathways in both diencephalon and liver of BC hens, and enhanced norepinephrine signaling in the cerebrum of BR and FR hens. To validate these findings, we performed a glucose tolerance test to assess insulin sensitivity and quantified the cerebral norepinephrine concentrations by ECD-HPLC. The results showed that BR and FR hens tended to exhibit higher insulin sensitivity and enhanced norepinephrine signaling compared with BC hens. Taken together, our findings suggest that housing conditions markedly shape the internal physiological landscape of laying hens, and also that environment-enriched cage-free contributes to improving metabolic and neurophysiological signaling.
The genus Moniezia comprises globally distributed parasitic cestodes that cause significant economic losses in domestic ruminants, yet its molecular characterization in wildlife remains limited. This study provides the first molecular confirmation of M. expansa in zoo animals in Taiwan. Specimens were obtained from a captive-born common eland (Tragelaphus oryx) and a domestic goat (Capra hircus); those from the eland underwent morphological examination of gravid proglottids, while all samples were analyzed genetically. Using the 18S ribosomal RNA, 28S ribosomal RNA, cytochrome c oxidase subunit 1, and NADH dehydrogenase subunit 1 (nad1) gene regions, we found identical strains of M. expansa in both the common eland and domestic goat in Taiwan, suggesting a local infection event. Notably, the eland-derived sequences clustered within lineages predominantly reported from Caprinae hosts, providing preliminary evidence of a potential spillover event, which aligns with the known broad host specificity of M. expansa. Haplotype network analysis further identified a novel nad1 haplotype within our sampled dataset and revealed high genetic diversity, which may support the hypothesis of complex expansion history of M. expansa. These findings underscore the value of molecular tools in clarifying parasite ecology in mixed wildlife-livestock settings and highlight the need for ongoing surveillance in zoological institutions.
During courtship, the abdominal gland of the male red-bellied newt (Cynops pyrrhogaster) is known to release a species-specific peptide pheromone, sodefrin, acting on the vomeronasal epithelial cells through yet-unidentified receptors. In addition, it became evident that the gland is able to synthesize various steroidal substances. Among them, pregnenolone and androstenedione are specifically released from the gland. Preference test and electro-olfactogram analysis revealed that the effects of both steroids were additive and that they acted synergistically with sodefrin to enhance pheromonal activity, possibly through the membrane receptors of the vomeronasal organ. This finding led to a breakthrough in the prediction that a steroidal substance with no species-specificity by itself contributes to urodele reproduction as a component of courtship pheromones.
