Journal of Veterinary Medical Science最新文献

Most members of the genus Gammacoronavirus infect avian hosts, but far fewer viruses have been characterized than in the other coronavirus genera, leaving their diversity largely unclear. Pigeon gammacoronaviruses were previously detected by consensus PCR, but only partial sequences were determined. In this study, we comprehensively analyzed public RNA-seq datasets and reconstructed two nearly complete genomes of pigeon gammacoronaviruses. Molecular evolutionary analyses showed pigeon gammacoronaviruses belong to the subgenus Igacovirus, and their pairwise distances to the members of this subgenus meet the International Committee on Taxonomy of Viruses (ICTV) species demarcation criteria, supporting their designation as a novel species in this subgenus. Notably, although nucleotide sequences are highly conserved among pigeon coronavirus variants, their 3'-genomic region exhibited differences in genome organization. These findings expand our knowledge of the diversity of gammacoronaviruses.

Neonicotinoids (NNs) are commonly used insecticides; however, their biotransformation in wild mammals remains poorly understood. Asian elephants, which are declining in numbers, may be vulnerable to these chemicals. In this study, we examined the liver metabolism of four major NNs: acetamiprid, imidacloprid, thiamethoxam, and clothianidin, using elephant liver microsomes. Metabolite profiling and targeted analysis were conducted with liquid chromatography quadrupole time-of-flight mass spectrometry and liquid chromatography tandem mass spectrometer, respectively. Results indicated that elephants mainly metabolize these NNs via reductive pathways, suggesting the involvement of nitroreductase-like enzymes or decarbonylation processes. Conversely, cytochrome P450-mediated oxidation may be limited; however, the roles of other enzymatic or microbial systems cannot be ruled out. These findings provide insights into xenobiotic metabolism in elephants, helping evaluate their toxicological vulnerability and supporting conservation efforts and risk assessments.

In recent years, several cases of Mesocestoides vogae infection have been reported in domestic dogs in Japan. These cases typically involved the detection of tetrathyridia and segmented worms with immature proglottids, but not mature adults with gravid proglottids. In this study, mature and gravid proglottids of M. vogae were identified in a domestic dog from Niigata Prefecture. Morphological examination confirmed the parasite to be a Mesocestoides species based on the presence of a well-developed parauterine organ. Further molecular analysis identified the parasite as M. vogae. This is the first report of gravid proglottids of M. vogae in a domestic dog, suggesting the potential role of dogs as definitive hosts in the transmission cycle of this parasite.

Trained immunity (TI) is a memory-like response of the mammalian innate immune system. However, a convenient assay system for measuring TI is not yet available. Insects possess only innate immunity and therefore have the potential for evaluating innate immunity-enhancing vaccines or chemicals. In this study, larvae of the silkworm (Bombyx mori) were injected with heat-killed (HK) Escherichia coli to induce immune priming, the insect counterpart of mammalian TI, which was confirmed with reduction in the infected Bombyx mori nucleopolyhedrovirus copy numbers, and gene expression was analyzed by RNAseq and reverse transcription quantitative PCR. Among the genes with significant expression changes, B. mori homologs of known human TI marker genes were identified. Changes in the expression of some of these marker genes in response to HK E. coli were also confirmed in mouse macrophage cell lines. Although B. mori responses were results of the insect immune priming and not equivalent to the mammalian TI, these results suggest the potential use of B. mori for detecting innate immunity-enhancing agents for mammals.

A 9-year-old Toy Poodle presented with sudden hypersalivation, vomiting, and retching unresponsive to symptomatic treatment. One month later, the mandibular salivary glands were enlarged and painful. Additional signs included weight loss, intermittent stiffness and tremors, and a fly-biting behavior, which is atypical for this disease. Magnetic resonance imaging revealed bilateral enlargement of the parotid and mandibular glands. Oral phenobarbital (PB) led to marked improvement, confirming phenobarbital-responsive sialadenosis. Residual hypersalivation and retching almost completely resolved within 24 hr after gabapentin (GBP) addition, with only mild hypersalivation (about 10% of the initial level) remaining. No recurrence was observed during a 3-year follow-up, during which PB (3.6 mg/kg administered orally twice daily [PO BID]) and GBP (15 mg/kg PO BID) were continued at the same doses.

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.

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 archive 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.

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.

A six-year-old spayed female domestic shorthair presented with a one-month history of respiratory distress. Echocardiography showed a large lesion adjacent to the left atrium that was compressing the pulmonary vein. Peak pulmonary venous flow velocity was high (1.5 m/sec). The diagnosis was pulmonary vein stenosis due to mass compression. Fine-needle biopsy cytology of the lung mass led to a direct diagnosis of lymphoma. After two weeks of treatment with L-Asparaginase and prednisolone, a reduction in the mass adjacent to the left atrium and slower peak pulmonary venous flow velocity (0.9 m/sec) were observed. Pulmonary vein stenosis was attenuated by a reduction in the size of lymphoma. This is the first case report of secondary pulmonary vein stenosis in a cat.

Beta-nicotinamide mononucleotide (beta-NMN) is a direct precursor of nicotinamide adenine dinucleotide (NAD⁺), a coenzyme essential for maintaining homeostasis in living organisms. NMN administration has attracted attention as a potential treatment for aging and age-related conditions, including diabetes, Alzheimer's disease, and chronic kidney disease. Duchenne muscular dystrophy (DMD) is a progressive, degenerative muscle disease caused by X-linked frameshift mutations in the Dmd gene. NAD⁺ levels in skeletal muscle decline in DMD pathology. In this study, we explored the therapeutic potential of NMN as an NAD⁺ booster for muscular dystrophy by administering NMN to DMD rats, which exhibit severe phenotypes comparable to those of human DMD patients, for 2 months. Although NMN administration did not improve muscle function in DMD rats, it did reduce the release of creatine kinase in their blood. RNA-seq analysis revealed that NMN administration could reverse DMD-related gene expression changes associated with skeletal muscle homeostasis. These results suggest that NMN can protect skeletal muscle against degeneration in DMD and may hold therapeutic potential for DMD patients.