Journal of Veterinary Medical Science最新文献

Ephemeroviruses, belonging to the genus Ephemerovirus within the family Rhabdoviridae of the Mononegavirales, are non-segmented, negative-strand RNA viruses that infect artiodactyls and blood-sucking arthropods. Although recent advances in sequencing technology have facilitated the identification of novel ephemeroviruses, thereby expanding our understanding of this viral genus, their diversity remains elusive, as evidenced by phylogenetic gaps between currently known ephemeroviruses. In this study, we analyzed publicly available RNA-seq data and identified a novel ephemerovirus, tentatively named Punjab virus (PBV), in a water buffalo (Bubalus bubalis [Linnaeus, 1758]). We obtained two separate PBV contigs from the RNA-seq data; the first contig covers the N, P, and M genes, while the second contig covers the G, α, β, γ, and L genes. Together, these PBV contigs represent 99% of the estimated complete viral genome. Mapping analysis revealed a typical transcriptional gradient pattern commonly observed in mononegaviruses, suggesting that the water buffalo is the authentic host for PBV. Sequence comparisons with its closest relatives indicate that the newly identified virus meets the ICTV species demarcation criteria for sequence divergence. Thus, this study contributes to a deeper understanding of the diversity of ephemeroviruses.

The Babesia divergens/B. capreoli group includes parasites with confirmed or possible zoonotic potential to cause human babesiosis. Currently, diagnostic antigen of the group has not been established. In this study, we investigated the ortholog of Bd37, a glycosylphosphatidylinositol (GPI)-anchored major merozoite surface protein of B. divergens sensu stricto, in the Asia lineage of the group. From two genomic isolates from sporozoite/sporoblast stages, three Bd37 gene variants, namely Bd37 JP-A, JP-B, and JP-C, were isolated with 62.3-64.1% amino acid sequence identity. Discriminative blood direct PCR revealed that Bd37 JP-A was encoded in all parasites infecting wild sika deer examined (n=22). While Bd37 JP-B and JP-C genes were randomly detected in 12 and 11 specimens, respectively. Sequencing of all JP-A variants revealed that the gene was polymorphic, with a low ratio of non-synonymous to synonymous substitutions (dN/dS) and that a highly polymorphic region was not related to predicted B-cell epitopes. A recombinant JP-A-based ELISA showed an overall positive rate of 13.9% in sika deer in Japan from north (Hokkaido) to south (Kyushu island) across 24 prefectures (n=360). This positive rate was twice as high as that examined by 18S rRNA-based PCR (6.6%). The geographical trends in infection rates were consistent. This study demonstrated that direct examination was informative for revealing genetic background and selecting antigen candidates. Bd37 orthologs may serve diagnostic purposes in combination with indirect fluorescence assay, which requires biological isolates.

To identify new criteria for selecting recipient dairy cows for embryo transfer (ET), we retrospectively examined the effects of the composition of early lactation milk on fertility risk in ET. This study investigated the association between milk fat (FAT), milk protein (PRO), and milk urea nitrogen (MUN) levels during early lactation, based on production records, and subsequent fertility risk in ET using contingency table analysis and multivariable logistic regression analysis, which included five confounding variables. The results showed that MUN levels during early lactation were negatively associated with fertility risk in ET, while FAT and PRO levels showed no clear association. A reduction in MUN levels during the peak lactation period suggests a deficiency in dry matter intake, an inadequate protein supply, and an imbalance in the ratio of proteins to fermentable carbohydrates in the rumen, which may have adversely impacted fertility risk in ET. Monitoring MUN levels is crucial for maintaining a proper protein balance. The results obtained in this study suggest that MUN levels in the early lactation phase obtained from production records can be used as a predictor of fertility in recipients to improve the fertility risk in ET. No special techniques or costs are required for using production records, making them easy to use in clinical practice. Our findings provide valuable insights for optimizing cost-effectiveness and fertility risk in ET and their clinical applications.

The red panda (Ailurus fulgens) can be found in zoos around the world, and various behavioral restraint procedures are used as part of their health care. Wild animals that are kept in zoos, including red pandas, are known to have a longer life span than those in the wild. Therefore, the health management of aging animals is considered especially important for zoos that maintain many precious wild animals. Blood pressure measurement is important for determining cardiovascular dynamics, however there are no reports of blood pressure measurements performed in red pandas without anesthesia. In this study, we measured blood pressure in four red pandas, over 4 years to establish a blood pressure measurement method using behavioral restraints. As a result, the blood pressure of red pandas was found to be similar to that of dogs and cats. In addition, in one case of red panda that evaluated high blood pressure during the measurement period, we added the antihypertensive drug and showed good effect for improvement of hypertension on long- term monitoring. Blood pressure values obtained using noninvasive methods were useful for red pandas. Moreover, these data were considered important for animal welfare.

Low-level laser (LLL) therapy is a well-known noninvasive treatment that stimulates fibroblasts to improve wound healing. LLL can improve fibroblast proliferation and migration without causing toxicity. The present study aimed to evaluate the effects of two laser wavelengths at different irradiation times on canine fibroblasts. Fibroblasts were isolated from canine oral mucosa. After seeding for 24 hr, the fibroblasts were irradiated using the Erchonia^®️ EVL dual-diode laser at wavelengths of 405 nm (5 mW) and 640 nm (7.5 mW) with irradiation times of 120, 360, and 1,800 sec. The proliferating and viability cells were evaluated 24 hr after laser irradiation. Wound closure rates were calculated at 0, 24, and 48 hr after laser irradiation. Parameters, including proliferation cell, cell viability, and cell migration, tended to be higher in the 360-sec group (405 nm) and 120-sec group (640 nm) than in other groups. Our findings suggest that LLL therapy at wavelengths of 405 and 640 nm with an irradiation time of 120-360 sec (0.26-0.51 J/cm²) can stimulate the proliferation and migration of canine fibroblasts. This finding may contribute to a better understanding of the beneficial role of LLL stimulation in canine wound healing.

A 4-year 9-month-old Holstein-Friesian dairy cow presented with anorexia. On physical examination, swelling of superficial lymph nodes, pelvic masses, and prolonged urination posture after urinating a small amount were noted. Hematological examination revealed no lymphocytosis. The bovine leukemia virus proviral load was relatively high. At necropsy, enlarged lymph nodes, a large mass in the pelvic cavity, and mass lesions in several organs were observed. Histopathological examination revealed the proliferation of neoplastic lymphocytes, which were immune-positive for CD79α and negative for CD3. B-cell clonality test indicated the presence of monoclonality in the urine, masses, and lymph nodes and minor clonality in the peripheral blood. These findings led to a diagnosis of EBL with minor clonality of B-cell in the peripheral blood.

A 35-month-old Japanese Black cow was presented to a local veterinarian with a main complaint of premature labor. There was no swelling of lymph nodes on the body surface and no palpable mass on rectal examination. Although atypical lymphocytes were observed in the peripheral blood, no lymphocytosis was recorded. On Day 12, the cow developed hindlimb paresis and was euthanized. Necropsy revealed swelling of some lymph nodes, and white nodules in uterus and right atrial appendage. Histopathological examination revealed B-cell lymphoma. In clonality analysis of peripheral blood and tumor tissue, monoclonal proliferation was detected by PCR for immunoglobulin light chain (IgL) λ, suggesting neoplastic proliferation of B-cell. IgL-PCR is thought to be a possible tool for diagnosis of B-cell lymphoma.

A 23-day-old Japanese Black female calf presented with distension of the lower abdomen. Abdominal ultrasonography revealed a cystic structure with fluid accumulation and moderate echoluminance in the right abdominal cavity. Ultrasonography and contrast-enhanced computed tomography revealed congenital hydronephrosis due to narrowing of the intrarenal ureter, and right kidney resection was performed. Blood urea nitrogen and serum creatinine levels, which were within reference values preoperatively, peaked on the third postoperative day and gradually decreased afterward until reaching preoperative values on the tenth day. In bovine hydronephrosis, nephrectomy may provide a favorable prognosis if one kidney is intact. Moreover, this case suggests that blood tests immediately after surgery are not suitable for evaluating residual kidneys.

We investigated antimicrobial resistance-related genes in 109 isolates of Trueperella pyogenes that were isolated in cattle and pigs. All 89 tetracycline-resistant T. pyogenes isolates carried the resistance gene harbored either tetW, tetM, tetA(33), tetK, or tetL. The ermX or ermB were detected in 18 of 23 erythromycin-resistant isolates. Streptomycin-resistant aadA1, aadA9, aadA11, aadA24, strA, or strB were detected in 25 of 83 isolates. There were significant differences in the percentages of tetA(33), ermB, aadA1, aadA9, aadA11, or aadA24 carriage between cattle and pig isolates. In addition, the Class 1 gene cassette was detected only in 17 cattle isolates. This suggests that T. pyogenes isolates acquire resistance gene in each environment of cattle and pigs, and that the transmission of the bacteria between cattle and pigs is limited.

Intranasal tumors in dogs are malignant solid tumors that are primarily treated with radiotherapy and often recur post-treatment. Combination therapy is pivotal in cancer therapy. Effective drugs include fluoropyrimidine 5-fluorouracil (5-FU) and toceranib phosphate. TS-1, an oral formulation containing the 5-FU prodrug tegafur and enzyme modulators gimeracil and oteracil, is proven to be safe in dogs with solid tumors. While the oral drug toceranib phosphate (Palladia^®) is safely administered, the combined toxicity with TS-1 is unknown. We aimed to determine the dosage of this combination in dogs. In the preclinical/clinical trials conducted here, we used a standard 3+3 cohort design with fixed doses of toceranib phosphate (2.4 mg/kg) administered thrice weekly. TS-1 administration was initiated at a dose of 0.5 mg/kg (upper limit 2.0 mg/kg) thrice weekly. Four cohorts were included to confirm the safety of TS-1 and toceranib phosphate. Each cohort was followed up for 1 month. The intranasal tumor types included in the clinical trial (n=13) were adenocarcinoma (n=7), squamous cell carcinoma (n=1), non-epithelial malignancy (n=2), undifferentiated carcinoma (n=1), and transitional carcinoma (n=2). The TS-1 dosage could be increased up to its dose limit in the preclinical/clinical trials. The TS-1 dose to combine with toceranib phosphate thrice weekly was 2.0 mg/kg. This regimen was well-tolerated in dogs. Thus, combined TS-1 and toceranib phosphate therapy is safe for dogs with intranasal tumors.