Journal of Veterinary Medical Science最新文献

We previously reported that poly (N-vinylacetamide-co-acrylic acid) coupled with d-octaarginine (VP-R8) efficiently introduces proteins and nucleic acids into cells. Based on these results, we hypothesized that VP-R8 can introduce a complex composed of guide RNA and Cas9 (RNP complex) into cells and induce genome editing mediated by the CRISPR-Cas9 system. We tested this hypothesis using a mouse dendritic cell line and mouse primary dendritic cells. The RNP complexes formed by guide RNA consisting of CRISPR RNA (crRNA), fluorescently labeled trans-activating crRNA (tracrRNA), and GFP-fused Cas9 were introduced into a mouse dendritic cell line using VP-R8 or control transfection reagents. Cells transfected using VP-R8 exhibited higher fluorescence than those transfected with other transfection reagents, indicating that VP-R8 efficiently introduced the RNP complex into the mouse dendritic cell line. Genome editing of the target DNA was detected in cells transfected with the RNP complex using VP-R8 and dominant relative to other transfection reagents. We also observed that VP-R8 effectively delivered RNP complexes consisting of single-guide RNA and Cas9 and induced genome editing in the dendritic cell line. Additionally, VP-R8 efficiently delivered RNP complexes into mouse primary dendritic cells and induced genome editing of the functional gene without producing early inflammatory cytokines. Thus, VP-R8 shows potential as a transfection tool to generate dendritic cells with specific gene regions deleted by genome editing via the CRISPR-Cas9 system. This approach aims to elucidate the detailed molecular mechanisms of dendritic cell function for its application to vaccines.

Male Sulawesi babirusas (Babyrousa celebensis) are known for their distinctive backward-curving canine tusks. Previous research on the anomalies of canines in male babirusa skulls has demonstrated a high prevalence of growth abnormalities due to failure in the rotation of the alveolar process and the curvature of the canines, while the numerical abnormalities were found to be rare. This study focused on supernumerary maxillary canines as observed in a wild-caught babirusa in an ex situ conservation program. This report represents the first publication of photographic evidence of a living babirusa with three right maxillary canines, one left maxillary canine growing toward the right side of the snout, and two overgrown mandibular canines threatening to erode the forehead.

The present study investigated whether behavioral changes predict the onset of left displaced abomasum (LDA) using a small, multi-sensor device attached to a cow collar that records data in real time over a 24 hr period. Behavioral data were collected from 17 LDA cows that had undergone surgery and 23 healthy dairy cows. The total rumination time over 10 days before and after LDA surgery in cows, was significantly shorter from 8 days before to 3 days after surgery, peaking at 216.4 ± 96.8 min on day before surgery than that in the control group (group: P<0.001). The total rumination time of LDA cows was significantly shorter than that of the control group at each time point (interaction effect: P<0.001). The diagnostic ability to predict the onset of LDA based on the cutoff value (≤360 min) of total rumination time 6 days before LDA surgery calculated using the Yohden index showed a significantly high AUC of 0.887 (P<0.0001) with high sensitivity (84.6%) and specificity (88.9%). In other words, it was suggested that the onset of LDA can be predicted by total rumination time from 6 days before surgery. An Animal Health Monitoring System (AHMS) not only warns of the onset of cattle diseases, such as LDA, several days in advance, but may also predict the onset of diseases up to 6 days in advance based on shortened the total rumination times, thereby contributing to the efficiency of work for farmers and veterinarians.

In this study, we analyzed the prevalence of diabetes in dogs over a nine-year period (2015-2023) in Japan using records provided by a pet insurance company. The observed prevalence rose from approximately 0.07% in 2015 to 0.30% in 2023, highlighting a steady upward trend. Logistic regression analysis confirmed this increase (regression coefficient β=0.121, P<0.001), with an odds ratio of 1.128 (95% confidence interval: 1.116-1.142), indicating an annual 12.8% increase in the odds of diabetes. A similar trend was observed among newly enrolled animals each year (β=0.0927, P<0.001; OR=1.097, 95% confidence interval: 1.076-1.119), suggesting a 9.7% annual increase in the odds of developing diabetes. The insurance dataset consistently showed a higher prevalence in males compared to females across all years. Additionally, we examined 209 clinical cases of canine diabetes collected from 21 veterinary hospitals to investigate age at diagnosis, sex, and neutering status. Case records indicated an age-related increase in diabetes incidence, with a peak between 8 and 10 years of age. The timing of diabetes onset did not significantly differ by sex or neutering status (χ² test, P=0.936). These findings highlight a progressive increase in canine diabetes prevalence in Japan and support the existence of a sex-based disparity in risk, with males being more susceptible.

Equine rhinitis B virus (ERBV), a member of the Picornaviridae family, is associated with mild to moderate respiratory illness in horses, yet its genomic diversity remains incompletely characterized. In this study, we performed metagenomic analysis on a rectal swab sample from a diarrheic foal confirmed to be positive for rotavirus A. Unexpectedly, we identified a highly divergent ERBV strain with a 9,448-nucleotide genome encoding a 2,721-amino-acid polyprotein. Sequence analysis revealed only 62.5-63.1% identity in the polyprotein and 47.1-49.8% in the VP1 region compared to known ERBV serotypes, suggesting a novel genotype. The genome exhibited typical picornavirus features, including a type II internal ribosome entry site (IRES), but also unique elements such as an 87-amino-acid insertion in the leader proteinase region and atypical cleavage motifs. A strain-specific RT-qPCR assay was developed alongside a broadly reactive assay targeting ERBV1-3. Screening of 37 rectal swab samples from horses revealed a 10.8% positivity rate using the new assay, with clustered cases from the same farm in 2022 and an additional case in 2024. No samples were positive using the broad-range primers, indicating potential gaps in surveillance. These findings highlight the importance of metagenomics in pathogen discovery and underscore the need for updated molecular tools to monitor genetically distinct ERBV strains and assess their clinical significance.

The large Japanese field mouse, Apodemus speciosus, is a rodent species endemic to Japan and is widely distributed throughout the country. It has been extensively used as a model organism in studies of geographic isolation and as an environmental bioindicator. However, there have been no reports on the establishment of pluripotent stem cells from this species that could be applied to developmental engineering. In this study, we attempted to generate induced pluripotent stem cells (iPSCs) from A. speciosus and successfully obtained cells that formed dome-shaped colonies and expressed pluripotency markers. These cells were capable of forming embryoid bodies that expressed markers of the three germ layers, and in vivo analysis using immunodeficient mice confirmed their ability to form teratomas. A. speciosus iPSCs established in this study not only contribute to the conservation of Japan's valuable animal genetic resources, but also provide a novel platform for investigating various biological processes that remain unexplored in this wild species.

Epileptic seizures in cats and dogs are etiologically classified as idiopathic epilepsy, structural epilepsy and reactive seizures, and semiologically as atonic, tonic/clonic, or generalized tonic clonic, focal and focal seizures evolving into generalized seizures. This retrospective study aimed to evaluate the semiological patterns and etiological causes of seizures in both species, and to assess interspecies differences in a regional veterinary population. Between January 2022 and January 2025, 77 cats and 106 dogs presented with seizures to Ondokuz Mayis University Animal Hospital (Samsun/Turkiye). After exclusions due to insufficient data or financial constraints, 24 cats and 29 dogs were included based on the Tier-I diagnostic criteria proposed by the International Veterinary Epilepsy Task Force. The relationships between species, age, sex, neuter status, seizure semiology and etiology were analyzed. Generalized tonic-clonic seizures were observed in 83.3% of cats and 72.4% of dogs. Idiopathic epilepsy was diagnosed in 41.7% of cats and 55.2% of dogs. Structural epilepsy in cats was mainly associated with feline infectious peritonitis, while canine distemper virus was the predominant cause in dogs. Although seizure types were broadly similar across species, some etiological differences appeared regionally. The high rate of generalized seizures may reflect observer bias or challenges in accurately classifying semiology without electroencephalography. This study highlights the utility of tiered diagnostic approaches in veterinary epileptology and underscores the need for updated, species-specific consensus guidelines for diagnostic approach and classification especially in feline patients.

Larvae of trombiculid mites (Acari: Trombiculidae), known as chiggers, are ectoparasites that parasitize various animals and transmit pathogens such as Orientia tsutsugamushi. We report the first record of chigger mites in the Ogasawara Islands, collected from Bonin Greenfinch Chloris kittlitzi and Warbling White-eyes Zosterops japonicus. By morphological and molecular analysis, the chiggers were identified to the genus Toritrombicula which predominantly parasitize avian hosts. Although the mites could not be identified to the species level, this finding provides new insight into the distribution of trombiculid mites of Japan.

The aim of this study was to distinguish canine lymphoma from other diseases, particularly reactive lymphoid hyperplasia (RLH), based on fine needle aspiration (FNA) images. We developed four deep learning models based on Vision Transformer (ViT) and Inception-v3, which were pre-trained image classification models. The two models out of four were ViT and Inception-v3, and the remained were the two types of combination, i.e., ensemble learning models, of ViT and Inception-v3; the mean of class probabilities of ViT and Inception-v3 (Ensemble model A; MEAN) and the maximum probabilities of ViT and Inception-v3 (Ensemble model B; MAX). A total of 2,290 FNA images of canine lymphoma and 871 FNA images of RLH were analyzed. The FNA images were obtained from the twenty-five slides of fourteen lymphoma cases and eight slides of seven RLH cases in two hospitals. Three types of training and test datasets were prepared from the above image datasets for fair evaluation of the models. Three deep learning-based image classification models (Inception-v3 and the two ensemble models) attained high performance of >80% accuracy, recall and area under the curve (AUC) values for all three datasets. ViT did not achieve high performance, except the precision (>0.85). This study is an example of showing potentials of deep learning models through image classification problem in canine lymphoma.

We report thrombotic cerebral infarction in a 13-year-9-month-old, female, captive red panda that presented with acute hemiparesis. The animal showed initial improvement with corticosteroid therapy, but its neurological condition worsened, leading to death on day 10. Necropsy revealed extensive cerebral infarction and severe Aspergillus infections in the nose and lungs, but not in the brain. Additionally, atrophy of the spleen and lymph nodes was observed. This is the first reported pathological evidence of thrombotic cerebral infarction in a red panda, and the data highlight the potential therapeutic efficacy of corticosteroids for this condition. It is also important to note that respiratory Aspergillus infection may be associated with cerebral infarction in red panda.