A field isolate of Mycoplasma synoviae, designated D14-383, caused pathogenic lesions in the air sac, trachea, lung, and ovary and induced a decline or stop in egg production and eggshell apex abnormalities in chickens after intratracheal inoculation. A live M. synoviae vaccine candidate was developed after in vitro passaging at 32°C from a wild-type M. synoviae strain originally isolated from the trachea of a 5-month-old asymptomatic layer chicken. In this study, the vaccine efficacy of the attenuated vaccine candidate strain against M. synoviae infection caused by the D14-383 strain was investigated. Eye-drop vaccination of 4-week-old chickens with 10^5.9 colony-forming units (CFU)/dose of the attenuated strain induced high levels of anti-M. synoviae antibodies, which were tested by serum plate agglutination, and a 95% seroconversion rate was maintained in the vaccinated birds for 108 weeks after vaccination. In the vaccinated birds, the air sac lesion score was 0.93 versus 4.0 in the unvaccinated group, as revealed by postmortem examination 7 days after challenge infection with the D14-383 strain. Moreover, the percentage of ovarian lesions was 15.9% (7/44 birds) and 73.3% (11/15 birds) in the vaccinated and unvaccinated groups, respectively. During the observation period after vaccination, egg production stopped in the unvaccinated birds but not in the vaccinated birds. Thus, the attenuated strain was proven to induce 2 years of protective immunity against M. synoviae infection in chickens.

Delivery of engineered interleukin-2 (IL-2) variants (muteins) is thought to be a promising cancer therapy in humans and mice. Our previous study indicated that bovine IL-2 (boIL-2) has a great potential to elicit NK cell activity for which distribution of IL-2 receptors on the target cell surface influences signal transduction. We developed nine boIL-2 muteins and examined the influence of the muteins on bovine peripheral blood mononuclear cells in vitro. On bovine peripheral mononuclear cells, NK cells strongly expressed CD122, followed by CD8⁺ T cells, while CD4⁺ T cells and γδ T cells did not show significant CD122 expression. All boIL-2 muteins showed decreasing in binding to boIL-2 receptor α, CD25, while maintaining their ability to bind to boIL-2 receptor βγ, CD122/CD132, heterodimer. The mutein F44A and E63A suppressed CD4⁺ T cell expansion but maintained the NK cell expansion. These results indicate that boIL-2 muteins can alter immunological outcomes and may be used for clinical intervention for a disease progression.

Feline polycystic kidney disease (PKD) is an inherited renal disorder observed in various breeds. Analyses of life expectancy and distribution of age at death among cats are not well documented. The current study preliminarily assessed life expectancy, cumulative survival rates, and distribution of age at death in cats with PKD by performing a follow-up investigation. This retrospective cohort study was conducted on 300 cats that tested positive for the feline PKD1 variant (c.10063C >A) in Japan. A life table analysis was performed, and a distribution graph of age at death was generated. The life expectancy at birth was approximately 12.7 years, with a 5- and 10-year cumulative survival rates of 95.1% and 61.3%, respectively. Of the 300 cats, 48 (16.0%) progressed to uremia, and 62 (20.7%) died of renal failure and other causes. The median age at death in 62 cats was 8 years, with the first decile being 5 years. The highest number of deaths was at the age of 7 years. The cumulative survival rate began to decline significantly at the age of 6–7 years. This study first performed a survival analysis of feline PKD and provided an important basis for understanding the patterns of overall mortality associated with this genetic disorder. Our findings emphasized the importance of frequent examination at a young age, with consideration of the remarkable decrease in the cumulative survival rate between the ages of 6 and 7 years.

To prevent the spread of bovine salmonellosis on farms, minimizing the detection time is an effective approach. At present, Salmonella spp. is typically detected via conventional culture methods involving an enrichment culture process taking several days. We attempted rapid detection of individual feces and environmental samples spiked with Salmonella Typhimurium or S. Dublin employing a loop-mediated isothermal amplification kit for detecting Salmonella spp. Notably, in comparison with conventional culture methods, the use of 18-hr enrichment cultures as samples can detect Salmonella spp. in feces and environment at least 24 and 48 hr earlier. Additional validation using clinical samples is necessary.

A four-year-old Toy Poodle treated with oclacitinib for one year presented with transient myoglobinuria associated with elevated serum creatine kinase (CK) levels only after exercise. An association between myoglobinuria and oclacitinib was suspected. An exercise stress test with or without oclacitinib was repeated twice on different days. Myoglobinuria and increased serum CK levels occurred only after testing with oclacitinib. The dog was diagnosed with exercise-induced mild rhabdomyolysis, which was presumably provoked by oclacitinib based on the results of the exercise stress tests. Rhabdomyolysis was considered an idiosyncratic adverse event for oclacitinib. This is the first report of exercise-induced mild rhabdomyolysis associated with oclacitinib in a dog.

Two dogs with patent ductus arteriosus and severe pulmonary hypertension were presented to our veterinary teaching hospital. In both dogs, sildenafil was initiated to treat pulmonary hypertension, and surgery was supposed to be scheduled after dose titration. Although no obvious improvement in pulmonary hypertension was observed, no dog had polycythaemia or an increased haematocrit level. The dogs underwent ductal occlusion, and treatment with beraprost sodium was subsequently initiated. Thereafter, severe pulmonary hypertension dramatically improved. No dog showed any clinical sign of right heart failure or adverse drug reaction postoperatively, thereby demonstrating the successful treatment of two dogs with patent ductus arteriosus and severe pulmonary hypertension, using sildenafil and beraprost sodium.

Hantaan virus causes hemorrhagic fever with renal syndrome (HFRS), a rodent-borne zoonotic disease. Korean hemorrhagic fever virus (KHFV), a strain of Hantaan virus, showed symptoms in mice similar to those of HFRS patients, including weight loss, renal medullary hemorrhage, hepatitis, and neutrophilia. Therefore, mice inoculated with KHFV were expected to serve as a model for HFRS. However, urinary symptoms characteristic of HFRS, such as proteinuria and hematuria, have not yet been examined. In this study, we attempted to evaluate renal function by analyzing urine. As a result, in mice inoculated with KHFV, oliguria and hematuria accompanied by weight loss were observed at 5–8 days after inoculation, and albuminuria was also observed. In addition, the viral load in the kidney and viral excretion into the urine were observed. When the neutralizing monoclonal antibody HCO2 against Hantaan virus was administered before inoculation, all symptoms were abolished. To clarify the therapeutic effect of HCO2 antibody, it was administered intravenously on days 1, 3, and 5 after infection. Weight loss and renal medullary hemorrhage were suppressed, and histological examination revealed micro renal hemorrhage in mice on day 5 administration. It was found that neutralizing antibody can be expected to alleviate symptoms even if it is administered late, and that early administration is more effective. These results indicate that this mouse model shows symptoms like human HFRS and can be used to evaluate antiviral effects.

A 4-month-old Japanese black calf exhibited anorexia and respiratory distress. Necropsy revealed a spongiform appearance of the rumen wall and histologically diagnosed as emphysematous rumenitis. The ruminal mucosa exhibited characteristic lesions of chemical rumenitis, so ruminal acidosis is suspected. Gram-positive bacilli were discernible on the degenerated ruminal mucosal surface and reacted with Clostridium species antibodies. Anaerobic cultures yielded Clostridium perfringens (C. perfringens), identified by multiplex polymerase chain reaction (PCR) as C. perfringens type A. The lumen and submucosa of the rumen showed a large ciliated trophozoite confirmed by PCR as Balantidium coli (B. coli). These findings suggest that ruminal acidosis leads to dysbiosis and allows C. perfringens type A to grow, causing emphysematous rumenitis and facilitating secondary B. coli infection.

Rhizopus microsporus is an opportunistic fungus that causes pneumonia and gastroenteritis in humans. This report describes two cases of mycotic gastritis caused by R. microsporus in Japanese Black calves. They exhibited diarrhea, wasting, and astasia. At necropsy, adhesion was observed between the abomasum and the abdominal wall (No. 1), and between the rumen and the spleen (No. 2). Histopathologically, severe necrosis with many mucoraceous fungi was observed in the abomasum (No. 1) and the rumen (No. 2), with fibrous granulation tissue forming in each adhered region. Molecular analysis identified both fungi as R. microsporus. Thymus hypoplasia was likely a predisposing factor, facilitating infection alongside the injury due to gastric catheter use and complications of white muscle disease.

Peripheral nerve sheath tumors (PNSTs) and meningiomas in feline spinal canal are sometimes difficult to differentiate solely on the basis of histopathology. In this study, immunohistochemical markers for differentiating PNSTs from meningiomas were investigated. In the control group, non-spinal PNSTs were immunoreactive for S100 and GFAP but not for E-cadherin, whereas intracranial meningiomas were immunoreactive for E-cadherin but not for S100 and GFAP. In the spinal tumor group, 2/7 cases were immunoreactive for S100 and GFAP but not for E-cadherin and were considered PNSTs. In addition, 5/7 cases were immunoreactive for E-cadherin and not for S100 and GFAP and were considered meningiomas. Immunohistochemistry for S100, GFAP and E-cadherin may aid in the differential diagnosis of feline spinal PNSTs and meningiomas.

Feline colorectal adenocarcinoma (FCC) is a locally invasive, highly metastatic malignant gastrointestinal tumor of colon or rectal mucosa in cats. When detected early, surgical resection may provide a promising prognosis. However, no clinical symptoms are observed in the early stages, and distant metastases or peritoneal dissemination are often already present at diagnosis. Therefore, after removal of the primary lesion, follow-up systemic therapy using anticancer drugs is required. However, the drugs currently used for FCC are not sufficiently effective in improving the prognosis, and it is necessary to develop novel and relevant preclinical models that accurately represent the disease. In this study, we developed three-dimensional culture models (organoids) from four FCC cases and examined their histopathological characteristics and drug-sensitivity profiles. FCC organoids were successfully generated and recapitulated the histological structure of the original tumor tissues. Furthermore, the FCC organoids expressed common markers (CK20 and CDX2) of FCC and exhibited tumorigenesis in vivo in mice. Cell viability assay showed that the FCC organoid lines exhibited different sensitivities to carboplatin, doxorubicin, and toceranib. Interestingly, the response of FCC organoids to toceranib varied among the lines and correlated well with the expression level of VEGFR-2, one of the target molecules of toceranib. These results suggested that FCC organoids can be used as preclinical models to advance molecular and therapeutic FCC research.

Osteoporosis is characterized by reduced bone density and increased fracture risk. The present study assessed anti-osteoporotic effects of isorhamnetin on ovariectomy (OVX)-induced osteoporosis in female rats. Osteoporosis was induced in OVXX-female Sprague-Dawley rats by using Freund’s Complete Adjuvant and randomly divided into the following groups (n=15): OVX control, alendronate (3 mg/kg, subcutaneous), and isorhamnetin (10, 20, and 40 mg/kg, p.o.), and received treatment for five weeks after OVX. In results following OVX, significant alterations in behavioral, biochemical, and histological parameters were observed. Conversely, isorhamnetin (20 and 40 mg/kg) treatment significantly improved (P<0.05) OVX-induced alterations in body, femur, and uterine weight, bone mineral content and density, but also effectively mitigated (P<0.05) elevated allodynia and hyperalgesia. It notably improved (P<0.05) changes in serum alkaline phosphatase, osteocalcin, C-terminal telopeptide of type I collagen (CTX-I), serum and urinary calcium, and phosphorus levels. Isorhamnetin markedly attenuated elevated (P<0.05) serum TNF-α, IL-1β, IL-6 levels but increased (P<0.05) serum IL-4 and IL-10 levels. Furthermore, mRNA expression of osteoprotegerin (OPG), runt-related transcription factor 2 (Runx2), and bone morphogenetic protein 2 (BMP-2) was upregulated (P<0.05), whereas receptor activator of nuclear factor kappa B ligand (RANKL) was downregulated (P<0.05). Histological analysis demonstrated that isorhamnetin effectively improved (P<0.05) OVX-induced inflammation, thereby preventing cellular infiltration, synovial hyperplasia, cartilage erosion, and pannus formation in bone specimens. In conclusion, isorhamnetin exerts its anti-osteoporotic potential by modulating pain (allodynia and hyperalgesia), serum biomarkers (osteocalcin, CTX-I, TNF-α, ILs), and bone signaling pathways (RANKL, OPG, BMP-2, Runx2).

Thoroughbreds born early in the year are believed to have an advantage in racing. However, the development of endocrine functions in early-born foals in the cold winter climate is unclear. The present study was conducted to elucidate the effect of birth month on the development of endocrine function in Thoroughbred foals born from February to May in Hokkaido by comparing hypothalamic-pituitary axis, adrenal and thyroid functions from birth to 24 weeks of age. Eighty-seven Thoroughbred foals were used to compare the changes in circulating luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, cortisol, and thyroxine among four birth month groups for each sex. The present study revealed that as foals grow, the hypothalamic-pituitary axis develops, allowing them to secrete LH and FSH in response to prolonged day length from about 10 weeks of age, regardless of birth month for both sexes. In addition, the increase in prolactin concentrations from May to August suggests that postnatal foals may have the ability to respond to prolonged daylength immediately after birth, independent of growth. Furthermore, circulating cortisol and thyroxine in the foals at birth were elevated regardless of birth month, suggesting that adrenal and thyroid functions were fully activated for the rapid growth during late gestation and adaptation to the external environment that occurs early postnatal period. In early-born foals, these hormone concentrations were found to be within the normal range, indicating that development of foals were not affected by the harsh Hokkaido winter.

Ischemia-reperfusion injury is caused by reactive oxygen production after revascularization. It is characterized by elevated ST segments on electrocardiogram (ECG), although the mechanisms remain unknown. In the present study, we reproduced the ST segment changes observed during ischemia-reperfusion injury by exposing bullfrog hearts to hydrogen peroxide (H₂O₂). The ECG showed a marked elevation of the ST segments, and the action potential in cardiomyocytes demonstrated shortening of its duration. H₂O₂ exposure did not affect the abundance of K_ATP channel proteins. However, pharmacological blockade by glibenclamide significantly suppressed H₂O₂-induced changes in ECG and tended to suppress cardiac action potentials. K_ATP channel stimulation by H₂O₂ is thought to be responsible for generating an electrical difference in cardiomyocytes and the subsequent ST segment elevation.

Avian haemosporidia are a group of vector-borne hemoparasites that are non-pathogenic to native bird hosts; however, some species/lineages cause severe disease or death in poultry and non-native birds. We investigated haemosporidian parasites in wild bird carcasses collected from four prefectures in eastern Japan. DNA was extracted from the liver, and the haemosporidian cytochrome b gene was amplified by nested PCR followed by direct sequencing. Of the 40 bird samples belonging to 25 species, 12 haemosporidian lineages were detected: four from Plasmodium, one from Haemoproteus, and seven from Leucocytozoon. Of these 12, two Leucocytozoon lineages were suspected to be novel. Leucocytozoon lineage TUMER02 was first detected in Japan. Six lineages were detected among the six novel host bird species.

Corneal epithelial cell sheet transplantation is a promising therapy for reconstructing the ocular surface in canines with severe corneal disease. Cultivation of these sheets typically requires feeder cells that support the proliferation and maintenance of immature epithelial cells by secreting growth factors. However, using conventional murine 3T3 fibroblasts as feeder cells raises ethical and safety concerns. This study investigated canine adipose-derived mesenchymal stem cells (cADMSCs) and bone marrow mesenchymal stem cells (cBMMSCs) as alternative feeder cells. Both MSCs were cultured alone or with canine corneal epithelial cells. Changes in epidermal growth factor, keratinocyte growth factor, and hepatocyte growth factor (HGF) expression in both MSC types were evaluated by quantitative polymerase chain reaction. HGF expression was further assessed by western blot and enzyme-linked immunosorbent assay. Canine corneal epithelial cell sheets were cultivated with cADMSCs, cBMMSCs, or 3T3 fibroblasts, or without feeder cells, and their structure and quality were evaluated histopathologically. Results showed that cADMSCs and cBMMSCs originally expressed soluble factors, and HGF mRNA expression significantly upregulated when co-cultured with epithelial cells. However, no significant differences in sheet structure or quality were observed among feeder types. In conclusion, cADMSCs and cBMMSCs are viable alternatives to 3T3 fibroblasts for cultivating canine corneal epithelial cell sheets. Canine corneal epithelial cells interact with MSCs and promote the secretion of soluble factors from MSCs to promote epithelial cell growth. Moreover, canine corneal epithelial cells may maintain their proliferative capacity and immature state independent of feeder cells.

Alpaca breeding is affected by environmental factors and management on farms. However, this has not yet been examined in detail in Japan. Therefore, we herein investigated the relationship between parturition in 65 alpacas on a Japanese farm and environmental factors. Parturition was observed every month, except for December, and the survival rate of crias was 81.5% (53/65). The gestation length was significantly longer for surviving crias than for dead crias (352.3 ± 17.9 vs. 338.7 ± 20.8 days, P<0.05). Birth weight was higher in surviving crias than in dead crias (6.7 ± 1.1 vs. 5.0 ± 1.0 kg, P<0.05). An analysis of the relationship between parturition and climate revealed a correlation between low ambient temperature one month before parturition and higher birth weights in surviving crias.

Due to the high level of heavy metals and harmful elements, United States and Europe are precautious in importing herbal medicines, which has seriously hindered the internationalization process of traditional Chinese and Mongolian medicines. Ga-Mu-Zhu-Er (GMZE) contains a wide range of chemical compounds and inorganic elements. This paper describes a validation process for the simultaneous analysis of 30 elements in Traditional Mongolian Medicine GMZE samples with closed-vessel microwave digestion technique followed by inductively coupled plasma-mass spectrometry (ICP-MS) analysis. The samples digested with concentrated nitric acid (65%, v/v) revealed recoveries ranging from 91.9 to 107.7%. Several other parameters, including linearity, specificity, the limit of detection (LOD) and quantification (LOQ), precision of measurement, repeatability, intermediate precision and accuracy, were validated. The LOD were found to be in the range of 0.00015–0.21 µg/L, and the LOQ were between 0.00046 to 0.64 µg/L. Three GMZE samples were analyzed. Among the analyzed elements, Ca, As, and Hg were the most abundant, whereas, Be and Ag were present in low concentrations in all the samples. The results obtained in our study demonstrated that the developed ICP-MS method is simple, fast, and reliable, which could be used for the routine quantitation of these 30 essential and non-essential trace elements in GMZE as well as other Traditional Chinese Medicines and dietary supplements, with acceptable analytical performance.

Bovine leukemia virus (BLV) is a global concern that significantly affects the productivity of dairy and beef cattle, leading to considerable economic losses. BLV is primarily transmitted through infected lymphocytes via both horizontal and vertical routes. Vertical transmission occurs through the colostrum, uterus, and placenta. Although the possibility of BLV transmission through infected semen during artificial insemination is a recognized concern. No such cases have been reported in Japan, while studies from other countries reported a low risk. In this study, we aimed to evaluate the presence of BLV provirus in commercially frozen semen to assess the potential risk of infection in Japan. A sufficient quantity of genomic DNA with adequate purity was extracted from 191 widely used commercially frozen semen samples obtained from top-ranking bulls in the annual market survey in Japan between 2000 and 2022 using the phenol-chloroform extraction method. No BLV provirus was detected in any of the 191 frozen semen samples using either BLV-CoCoMo-qPCR-2 targeting the BLV long-terminal repeat region or nested polymerase chain reaction targeting BLV gp51 env gene. Similarly, the results are consistent with reports from other countries. Therefore, the findings of this study suggest a low risk of BLV transmission through frozen semen in Japan. Our study further supports that artificial insemination combined with the selection of non-infected cows for breeding are effective measures to prevent the spread of infection.

African pygmy hedgehog adenovirus 1 (AhAdV-1) was first identified in 2020 from a colony of African pygmy hedgehogs that succumbed to severe bronchopneumonia in Japan. AhAdV-1 is closely related to Skunk adenovirus 1, which was isolated from a wild skunk with acute hepatitis and pneumonia in Canada in 2015. Similar viruses have been isolated or detected in a diverse range of animals across multiple countries. While adenoviruses are generally considered highly species-specific, the host range of AhAdV-1 remains unclear. This study aimed to investigate the potential host range of AhAdV-1 through serological surveillance among 17 exotic animal species that visited a veterinary hospital in Fukuoka, Japan. Neutralizing antibodies against AhAdV-1 were detected in several species, with particularly high seroprevalence observed in meerkats (41%), ferrets (62%), and African pygmy hedgehogs (63%). Notably, ferrets and hedgehogs with a history of respiratory symptoms exhibited significantly higher seroprevalence compared to asymptomatic individuals. These findings suggest a broad host range for AhAdV-1, with certain species showing high exposure rates. Further investigations are needed to determine the sources and transmission routes of AhAdV-1, as well as its potential for zoonotic infection.

We determined the 50% porcine infectious dose (PID₅₀) of the classical swine fever virus (CSFV) JPN/1/2018 strain currently circulating in Japan. Twelve piglets were orally inoculated with 10^1.0, 10^3.0, or 10^5.0 50% tissue culture infectious dose (TCID₅₀) of the virus. All piglets receiving 10^5.0 TCID₅₀ developed typical clinical signs with viral RNA detection in their blood from 2 days post-inoculation (dpi). One piglet receiving 10^3.0 TCID₅₀ was confirmed to be infected at 4–5 dpi, while the remaining piglets in this group became infected later, with evidence of infection detected at 11–14 dpi. These results suggest that only the first infected piglet was directly infected by the viral inoculum, while the remaining 3 piglets were indirectly infected through horizontal transmission from the first infected piglet. No piglets inoculated with 10^1.0 TCID₅₀ became infected. Based on these infection patterns, the PID₅₀ was calculated as 10^3.5 TCID₅₀, providing essential data for infection risk assessment and establishing target reduction titers for disinfection against the JPN/1/2018 strain.