We examined the orbicularis oculi (OC) muscle and its innervation among the markedly modified facial muscles of odontocetes, clarifying features related to secondary adaptations to aquatic life. The OC muscle has been described as a well-developed sphincter encircling the eye in cetaceans; however, this study revealed two distinct types of OC morphology among odontocetes. In specimens from the families Kogiidae and Ziphiidae, the muscle bundles of the OC completely encircled the palpebral fissure in concentric circles, similar to that of Bovidae specimens. However, in specimens from Phocoenidae and Delphinidae, the OC featured a muscular area with muscle fibers and an aponeurotic area comprising collagen fibers lacking facial nerve distribution. Our results suggest that this aponeurotic area was acquired in the common ancestor of species within the Delphinoidea superfamily, and that the upper eyelid is less mobile than the lower eyelid. The palpebral branches, which originate from the facial nerve, extend from the lower to the upper palpebral regions in the examined odontocetes, showing a clear difference from the entry course seen at the lateral canthus in artiodactyls. The proximal palpebral branches diverged directly from the facial nerve trunk, forming a characteristic diverging point distal to that of artiodactyls. These branches probably correspond to the auriculopalpebral nerve, which has lost the rostral auricular branch component. The morphological changes in cetacean heads also led to changes in the branching pattern and pathway of the facial nerve.

Arterial distribution to the tensor fasciae antebrachii (TFA) muscle is little described in the veterinary literature. In this study, we investigated TFA vascularity intra- and inter-specifically, using specimens obtained from dogs, cattle, pigs, and horses at necropsy. Canine TFA specimens showed vascularity from the collateral ulnar artery in all cases, and from the thoracodorsal artery in some cases, with no brachial or deep brachial arterial vascularity. Bovine TFA specimens showed vascularity from the thoracodorsal artery. All porcine TFA specimens showed deep brachial arterial vascularity. Equine TFA specimens showed strong subscapular arterial vascularity, as well as some supply from branches of the deep brachial artery. This article will encourage further active research.

This study investigated the relationship between herd average annual somatic cell count (Herd SCC) and epidemiological indicators of intramammary infection (IMI) in the nonlactating period. We also aimed to establish a predictive model and benchmark based on epidemiological indicators of non-lactating IMI (IMI indicators) for a dairy herd in Hokkaido, Japan. Individual SCC data were extracted from 3 years of dairy herd improvement (DHI) data from 3,173 dairy farms in Hokkaido, and three IMI indicators were calculated: first-calving cow infection rate (FCIR) from first-time DHI results, dry cow cure rate (DCR), and dry cow new infection rate (DNIR) based on pre- and postpartum DHI results. A SCC of ≥200,000 cells/mL in individual cows was defined as IMI, and IMI indicators were then calculated. Dairy farms were classified into five levels based on the Herd SCC shown in the DHI data. Significant correlations were observed between Herd SCC and all IMI indicators ( ρ =0.37–0.44). The correlations suggested significant positive relationships between Herd SCC, and average FCIR and average DNIR, respectively, and a significant negative relationship between Herd SCC and average DCR. Generalized linear model analysis confirmed the significance of the correlation between Herd SCC and IMI indicators, even after adjusting for environmental and management factors, such as housing system (P<0.01). By comparing the benchmarks obtained in this study, dairy farmers can achieve IMI control through appropriate management in the non-lactating period based on target values for improvement, depending on Herd SCC.

The mechanism of multi-azole antifungal resistance in the dermatophyte Microsporum canis was investigated through a transcriptome analysis of the multi-azole–resistant strain LLP25-013. Strain LLP25-013 was cultured with and without itraconazole (ITCZ), after which total RNA was extracted from mycelial samples. Whole-RNA sequencing was performed using a DNBSEQ-G400 system. A total of 8,846 expressed genes were detected in samples of both total RNAs from both ITCZ-treated and ITCZ-free samples. Genes sequenced with more than 10,000 reads were selected from ITCZ-treated and ITCZ-free samples, and the expression levels were compared. Treatment with ITCZ upregulated the expression of 63 genes compared with no ITCZ treatment. By contrast, ITCZ treatment downregulated the expression of 253 identified genes. ITCZ addition reduced the expression of many genes in M. canis, which could be related to the broad-spectrum antifungal drug resistance of this organism. Among the upregulated genes, the ATP-binding cassette (ABC) transporter gene is involved in resistance in other dermatophytes. Co-culture of strain LLP25-013 with milbemycin and other azoles suggested that the isolate acquired azole resistance through high expression of the ABC transporter.

Bovine mastitis may cause intractable, chronic infection in cases where the causative pathogen forms a biofilm; however, data are lacking on Staphylococcus aureus (S. aureus) biofilm in Japanese dairy herds, and the relative efficacy of antimicrobial agents to treat it. Accordingly, we aimed to investigate the biofilm-forming potential of S. aureus isolates obtained from the milk of Holstein dairy cows with clinical mastitis, and to elucidate the effects of five clinically used antibiotic drugs against S. aureus biofilms. We found that 14/24 S. aureus isolates formed biofilm. All five antibiotic drugs demonstrated an inhibitory effect on S. aureus at the planktonic stage (based on minimum inhibitory concentrations); however, only the three fluoroquinolone antibiotics (orbifloxacin, enrofloxacin, and marbofloxacin) and cefazolin inhibited biofilm formation (based on minimum biofilm inhibitory concentrations). However, none of the five antibiotics proved effective against formed biofilms (based on minimum biofilm-eradicating concentrations). Accordingly, we suggest that systemic fluoroquinolone antibiotic or intra-mammary cefazolin may prevent biofilm formation in mastitic cows infected with S. aureus, if administered at a sufficiently high concentration and a sufficiently early stage of the disease (before biofilms are actually formed), but that antibiotics may have little efficacy once the biofilm is established.

This report describes two dogs with high-grade multicentric B-cell lymphoma that relapsed 3 months after completing a 6-month-long chemotherapy regimen with L-asparaginase, cyclophosphamide, doxorubicin, vincristine, and prednisolone (L-CHOP). Both were re-treated with L-CHOP, achieving complete remission (CR) before undergoing sequential half-body irradiation (HBI; 6 Gy per fraction to cranial and caudal body, 2 weeks apart). Caudal HBI caused grade 3 gastrointestinal toxicity in both dogs and grade 3 thrombocytopenia in one; however, both remain in CR at the time of writing this report (i.e., 483 and 490 days post-relapse). These findings suggest that combining HBI with chemotherapy may offer benefits in relapsed canine lymphoma, especially when dogs are in CR at the time of HBI.

This longitudinal study evaluated whether an introductory laboratory animal science lecture changes first-year veterinary students’ compassion toward laboratory animals. A pre- and post-lecture survey revealed a significant increase in total compassion scores. The educational impact varied based on students’ backgrounds; for instance, significant score increases were observed in students with prior pet ownership and those without experience in animal protection activities. Improvements were notable in attitudes toward allowing natural behaviors and the importance of legal regulations. A slight decrease in some anti-compassion item scores was also observed, potentially indicating the early formation of a professional utilitarian perspective. These findings suggest that foundational education is effective in enhancing compassion, suggesting that science-based knowledge is crucial for developing the professional ethical framework essential for a “culture of care”.

Acceptable euthanasia methods must rapidly induce unconsciousness and death without pain or distress. We evaluated intraperitoneal thiamylal sodium (TM; 150 mg/kg; hereafter TM150) in male Sprague–Dawley, Wistar, and Fischer 344 rats. TM produced immobilization, loss of righting reflex, respiratory arrest, and cardiac arrest in all strains, with the shortest latencies in Fischer 344. Plasma chemistry showed strain-dependent shifts, including aspartate aminotransferase (AST) increases and variable alanine aminotransferase (ALT) responses; chloride and calcium showed small, non-uniform changes across strains, and most values remained within commonly cited reference ranges. These findings most likely reflect perimortem physiology and methodological factors superimposed on strain baselines rather than primary organ injury. TM150 is therefore effective for rat euthanasia, although post-TM plasma biochemistry should be interpreted cautiously.

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity lung disorder caused by chronic exposure to Aspergillus fumigatus (Af). Existing mouse models do not fully capture the severity of ABPA. This study developed a novel murine model of ABPA using the spontaneously eosinophilic Yama mouse. Female Yama and BALB/c mice were sensitized and challenged with Asp f1, a major allergen derived from Af. Peripheral eosinophil counts, serum IgE levels, and histopathological changes in the lungs, including goblet cell hyperplasia, mucus plugging, collagen deposition, eosinophil cationic protein (ECP), and CD117/c-kit expression, were assessed. Cytokine and fibrosis-related gene mRNA expression of interleukin-4 (IL-4), IL-5, IL-6, IL-13, transforming growth factor-β (TGF-β), and Col1a1 was also measured. Compared to BALB/c mice, Asp f1-challenged Yama mice exhibited sustained eosinophilia, increased IgE, pronounced goblet cell hyperplasia with mucus plugging, collagen deposition, and elevated eosinophil cationic protein (ECP) expression. Yama mice also showed more significant peribronchial inflammation and pulmonary fibrosis. RT-PCR analysis demonstrated substantial increases in IL-4, IL-5, IL-6, IL-13, and Col1a1 transcripts, indicating a Th2-dominant immune profile and enhanced fibrotic activity. The minimal differences in TGF-β expression between Asp f1– and saline-treated mice indicate that fibrosis in Yama mice may proceed via a TGF-β-independent pathway. These findings establish the Yama mouse as a novel model for ABPA research, closely replicating the immunopathological features of severe human ABPA. This model provides a reliable platform to investigate eosinophil-driven lung fibrosis mechanisms and evaluate hypersensitivity responses contributing to human ABPA onset and progression.

Diaphragmatic hernia, the protrusion of abdominal organs through a congenital defect or traumatic rupture of the diaphragm, has rarely been documented in wildlife. We report a severe traumatic diaphragmatic hernia in a juvenile female raccoon dog. Postmortem examination revealed a herniation at the Bochdalek site in the right dorsolateral part of the diaphragm, with extensive intestinal and hepatic displacement into the right thoracic cavity. Rib osseous callus indicated healed fractures of the 7th and 8th right ribs. These findings provide an understanding of traumatic diaphragmatic hernias and contribute to the pathological assessment of wildlife health.

In previous experiments using bullfrog hearts, we successfully replicated both the elevation and reciprocal depression of the ST segment observed in electrocardiograms of human ischemic heart disease. In this study, we induced subepicardial burn injuries in the lateral part of the frog heart ventricle, which allowed us to mimic typical electrocardiographic changes associated with human lateral wall myocardial infarction. These changes included a marked ST segment elevation in the high lateral limb leads (I, augmented Voltage Left; aVL) and reciprocal ST segment depression in the opposite limb leads (III, augmented Voltage Foot; aVF). We surmise that the electrical disparity between injured and intact cardiomyocytes generates currents of injury, leading to the observed ST segment alterations.