Prosaposin is a precursor of lysosomal hydrolases activator proteins, saposins, and also acts as a secretory protein that is not processed into saposins. Prosaposin elicits neurotrophic function via G protein-coupled receptor (GPR) 37, and prosaposin deficiency causes abnormal vestibuloauditory end-organ development. In this study, immunohistochemistry was used to examine prosaposin and GPR37 expression patterns in the mouse cochlear and vestibular nuclei. Prosaposin immunoreactivity was observed in neurons and glial cells in both nuclei. GPR37 immunoreactivity was observed in only some neurons, and its immunoreactivity in the vestibular nucleus was weaker than that in the cochlear nucleus. This study suggests a possibility that prosaposin deficiency affects not only the end-organs but also the first center of the vestibuloauditory system.

Koalas are iconic mammals indigenous to Australia. These rare animals and their habitats are occasionally associated with pathogenic fungi, including species of Cryptococcus, and consequently, monitoring the mycobiota of areas inhabited by koalas is of considerable importance. In this report, we describe a novel basidiomycetous yeast isolated from a site in Kanazawa Zoo, Japan, associated with captive koalas. Swab samples were collected from koala breeding environments, from which we isolated a novel unencapsulated yeast characterized by ovoid to ellipsoidal cells (3.2–4.9 × 3.5–5 μm). These cells were observed to undergo polar budding and grow as parent bud pairs, with an optimal growth temperature of 28°C. Colonies grown on yeast extract peptone dextrose agar at 28°C have a characteristic coral pink color. On the basis of physiological, morphological, and molecular characters, the new species was placed in the genus Begerowomyces, and the name Begerowomyces aurantius JCM33898^T(LSEM1333^T=CBS16241^T) is proposed.

Clostridium perfringens toxinotype E infections are rare in calves, and the development of intestinal lesions were commonly observed. In 2012, a 6-day-old calf in Japan exhibited swelling with emphysema on the right gluteal region, sudden paralysis of the hind limb and dysstasia. A pathological examination revealed myositis of the gluteal muscle and neuritis of the ischiatic nerve. C. perfringens type E strain CP118 was isolated from the affected muscle. However, the intestinal symptoms and lesions that commonly develop in type E infections in calves were not detected in the present case. Genome analyses revealed that CP118 possessed 16 virulence-related genes, including enterotoxin, and was closely related to other type E and F strains. Particularly, CP118 was more closely related to type E strains from humans, including a food poisoning case, than calf isolates, suggesting its potential to cause food poisoning in humans and, thus, its importance as a potential risk to public health. Since CP118 did not possess the reported toxin genes associated with neuropathy, pyogenic inflammation caused by CP118 and/or other bacteria may have damaged the ischiatic nerve, resulting in neuropathy. Alternatively, unidentified CP118 toxins may have caused the neuropathy. This is the first study to report C. perfringens type E infection with peripheral neuropathy. The distribution of all the reported virulence-related genes in the C. perfringens population as well as the details of this rare case will provide further insights into C. perfringens type E infections.

This study aimed to characterize the antimicrobial resistance and virulence of Enterococcus from dogs and cats in Northeast China and evaluate its zoonotic risk based on a total of 469 enterococci strains from 610 samples, including 238 strains of E. faecium and 128 strains of E. faecalis. The isolation rate from police dog samples was 93.79%, pet dog samples was 69.90% and pet cat samples was 76.67%. The differences in the prevalence of E. faecalis among different hosts were statistically significant (P<0.05). The assays showed that most of the virulence genes detected were existed in E. faecalis and police dogs carried the least number of virulence genes. The correlation between enterococcal surface protein (esp) and aggregation substance (asa1) was determined. Enterococci are most resistant to tetracycline and erythromycin, 68.92% of the isolates were classified as multiple drug resistant. Significant differences (P<0.01) were found between E. faecium and E. faecalis in the resistance rates of nine antimicrobials. Four positive and four negative correlations were found between virulence genes and antimicrobial resistance. The results show that Enterococcus colonization and excretion in dogs and cats were related to animal species and living environments. Some correlation between virulence factors and antimicrobial resistance was obtained. This study confirmed the presence of strains carrying multiple virulence factors and antimicrobial resistance at the same time, suggesting a public health risk for dogs and cats as reservoirs of enterococci.

We investigated the antimicrobial susceptibility of Trueperella pyogenes isolates from cattle and pigs diagnosed with septicemia at slaughter. The strains investigated in this study were found to be susceptible to ampicillin, cefazolin, gentamicin, and levofloxacin. However, 53.3% of the strains were resistant to tetracycline, 49.7% to streptomycin, 13.8% to erythromycin, 13.2% to clindamycin, and 1.2% to oxacillin and kanamycin. We also found that the resistance of pig-derived strains of T. pyogenes to tetracycline, streptomycin, erythromycin, and clindamycin was higher than that of cattle-derived strains, and these strains were resistant to up to four antimicrobial agents used simultaneously. The present results provide new data on the range of the minimum inhibitory concentration (MIC) values of various antimicrobial agents for T. pyogenes isolated from livestock with septicemia. The breakpoint values used in this study are generally considered applicable.

The aim of this study was to investigate changes in expression levels of immune factors of peripheral blood mononuclear cells (PBMC) after oral supplementation of live yeast Saccharomyces cerevisiae to healthy Japanese Black (JB) calves. This study examined JB calves (N=28): 14 calves (SC Group) received 10 g/calf/day of Saccharomyces cerevisiae (SC) (Acti-Saf Sc 47), and the other calves did not receive supplement (Control Group). Blood samples were collected 9 times during experimental period (1, 2, 3, 4, 5, 6, 7, 8 and 9 months of age), and analyzed for cytokines and chemokines mRNA expression of PBMC using Real-time PCR. The level of beta Hydroxybutanoic acid (BHB) in the SC Group was significantly high at 7 and 8 months of age compared to that in the Control Group. Lymphocyte counts in the SC Group were significantly higher at 2 and 5 to 6 months of age compared to the Control Group. Significant differences were found for IL-12p40 level at 4, 7 and 9 months of age, and for IFN-γ level at 6, 7 and 8 months of age. The level of CXCR3 was significantly higher at 6 to 7 months of age by dietary SC supplementation. These results indicated that SC supplementation improved the cellular immune responses of JB calves.

This study aimed to elucidate the distribution of enrofloxacin (ERFX) within the bronchoalveolar region of pigs. Six clinically healthy pigs were allocated to intramuscular treatments with either a single dose of 5 mg/kg or 7.5 mg/kg ERFX. Samples of plasma and bronchoalveolar lavage fluid (BALF) were obtained from each pig 0 (before administration), 3, 8, and 24 hr after ERFX administration. The ERFX concentrations in pulmonary epithelial lining fluid (ELF) and BALF cells showed a similar pattern during the experimental period, whereby ERFX concentrations in both ELF and BALF cells were higher than those in the plasma. These results suggest that intramuscularly injected ERFX is well-distributed in the bronchoalveolar region.

Canine Malassezia dermatitis and otitis externa are generally treated by antifungal drugs. However, multi-drug-resistant strains of Malassezia pachydermatis have been reported worldwide. Given the presence of these multi-drug-resistant strains, it is unclear which antifungal agent is the most effective for canine Malassezia dermatitis and canine otitis. In this study, we attempted to determine the most effective drug against azole-resistant M. pachydermatis. Susceptibility to azoles and terbinafine (TBF) was assessed using a modified broth microdilution method. In all tested isolates, the minimum inhibitory concentration at 90% of organisms (MIC₉₀) were 16 to >32 μg/mL for the azoles, and 2 μg/mL for TBF. All of the strains that showed low susceptibility to both itraconazole and miconazole were also relatively susceptible to TBF.

The larval form of the Phyllobothriidea cestode was found in the blubber of a Cape fur seal (Arctocephalus pusillus pusillus) from a zoo in Japan. Bladder-bearing larval cestodes with a scolex have been occasionally reported from blubbers of pinnipeds and morphologically identified as Clistobothrium delphini (formerly known as Phyllobothrium delphini) or rarely Clistobothrium grimaldii (Monorygma grimaldii). Although the larvae here morphologically resembled C. delphini, the 28S rDNA sequence was 100% (1,430/1,430 bp) homologous to the registered sequence of C. grimaldii (GenBank Accession No. KU724058). This discrepancy between morphological and molecular analyses confirms the difficulty of identifying C. delphini and C. grimaldii larvae based solely on morphology, and the need for molecular data to elucidate the morphological variations in Clistobothrium parasites.

While numerous scientific studies have suggested the usefulness of autopsy imaging (Ai) in the field of human forensic medicine, the use of imaging modalities for the purpose of veterinary forensics is currently scant. The current study performed Ai on suspicious dead animals requested by the police department to determine their cause of death. Radiography and/or computed tomography and/or magnetic resonance imaging were performed on 39 suspicious dead animals before necropsy. After diagnostic imaging, pathological examination was performed, with drug testing added as needed. Among the 39 cases, 28, 6, 3, 1, and 1 involved cats, dogs, rabbits, a ferret, and a pigeon, respectively. The major Ai findings included skull and rib fractures, subcutaneous emphysema, pneumothorax, pneumoperitoneum, diaphragmatic hernia, and abdominal rupture. The leading causes of death, determined comprehensively via Ai and pathological reports and drug test results, included traumatic impact, blood loss, poisoning, suffocation, tension pneumothorax, starvation, and drowning, all of which have been strongly suspected to indicate animal abuse by humans. All eight cases of skull fractures and all five cases of poisoning, including suspected poisoning, were of cats. As the numbers of dogs and cats in Japan are almost equal, violence against cats may occur more frequently than dogs. Ai can be a valuable examination tool for veterinary forensic cases. As computed tomography is useful for ruling out fractures that screening computed tomography before necropsy is a more practical option for veterinary forensics.

In veterinary clinics, esophageal reconstruction is essential in many clinical situations. In this study, two autografts, the tunica vaginalis (TV) and the buccal mucosa (BM), were proposed to reconstruct a semi-circumferential cervical esophageal defect in dogs. This study aimed to verify whether these two grafts could successfully patch esophageal defects. Twelve male mongrel dogs were divided into two groups. Following cervical esophagoplasty, the defective area was patched with either a TV or a BM graft. Comprehensive clinical, serum biochemical, and histological analyses were performed to evaluate the two grafts. Throughout the study (120 days), the dogs survived the procedure well with minor complications. The lumen of the patched areas was covered with mucosa, with slight scar retraction. Compared with that of the natural esophagus, the average relative luminal diameter was not significantly decreased. Importantly, the measured cortisol and inflammatory marker levels returned to the preoperative levels after 14 days. Although histological examination revealed that both grafts repaired the esophageal defect with complete re-epithelialization, the BM graft showed a histological structure similar to that of the natural esophagus. Both grafts effectively repaired the esophageal defect with minor complications; therefore, both are recommended as promising low-cost clinical alternatives for cervical esophagoplasty in dogs.

Investigating the characteristics of tracheas can help the understanding of diseases related to the trachea, particularly tracheal collapse (TC) in dogs. This study aimed to compare the mechanical properties of tracheas from New Zealand White (NZW) rabbits and dogs and to introduce a method for inducing a model of TC in the normal trachea. Tracheal samples were obtained from NZW rabbit cadavers (n=5) weighing 3.62–3.92 kg and from dog cadavers (n=5) weighing 2.97–3.28 kg. Three live NZW rabbits weighing 3.5–4.0 kg were used to establish the model. The radial forces of both sample sets were measured using a digital force gauge and statistically compared. Subsequently, TC was surgically induced in three female NZW rabbits by physically weakening their tracheal cartilage under general anesthesia. Their clinical signs were monitored for 3 months, and radiographic examinations were performed monthly for 3 months. The mean radial forces of the two sample sets were comparable (P>0.05). The clinical signs, radiographic examinations, and macroscopic examinations were all comparable to those of dogs with TC. The cadaveric study between the rabbits and dogs demonstrated that the surgically induced rabbit model of TC is an excellent candidate for the experimental study of dogs with TC. This study also provides a reference of tracheal radial force values to enable selection of appropriate mesh types and wire diameters of self-expanding metal stents.

A 12-year-old French bulldog presented with a mass on the right lower jaw. Computed tomography revealed that the mass originated from the salivary gland and was not continuous with the right mandible. The mass was surgically removed and subsequently diagnosed as extraskeletal osteosarcoma of the salivary gland following histopathological and immunohistochemical examinations. Although the surgical margin was clear, postoperative adjuvant therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) was initiated. Lung metastasis was observed 249 days after the initial examination; therefore, toceranib was initiated with NSAIDs. The dog died 496 days after the initial examination of this disease progression but had good long-term management with a combination of surgery, NSAIDs, and toceranib.

An intravaginal thermometer was inserted into a 59-month-old Japanese black cow to predict calving. After calving, the thermometer penetrated the vaginal wall and could not be removed by farm staff. Surgery to remove the thermometer was successful. The cow left the animal hospital without hospitalization. In the follow-up, the cow remained healthy on the farm for more than one year and is now pregnant. No symptoms related to damage to the vagina or infection developed. This is the first case report of a vaginal laceration caused by an intravaginal thermometer in a Japanese black cow. Insertional vaginal devices may cause vaginal lacerations in cattle.

Classical swine fever (CSF) live vaccine used in Japan, GPE⁻ strain, is produced using guinea pig kidney (GPK)-derived primary culture cells. This means that a large number of guinea pigs are used to generate the primary GPK cells needed to produce the CSF live vaccine, and alternative solution is desired. Hence, we established two GPK cell lines capable of culturing the GPE⁻ strain: spontaneously immortalized GPK (GPK-SI) cells were generated by repeated passaging of primary GPK cells, and the other cell line, artificially immortalized GPK (GPK-AI) cells, were obtained by introducing the SV40 large T antigen gene into primary GPK cells. Both cell lines were susceptible to the GPE⁻ virus, and the virus grew more efficiently in GPK-SI cells at 37°C. When the culture temperature was set to 30°C, the virus titer reached 10^4.8 50% Tissue Culture Infectious Dose (TCID₅₀)/mL in GPK-SI cells 7 days after virus inoculation at a multiplicity of infection (MOI) of 1, which was equivalent to that in cells cultured at 37°C. When the virus was inoculated at MOI <1, the virus titer 7 days after inoculation was higher when cultured at 30°C than when cultured at 37°C in both cell lines, reaching 10^5.63 TCID₅₀/mL in GPK-SI cells. These results indicate that GPK-SI and GPK-AI cells can potentially replace primary GPK cells for the production of CSF live vaccines. This could also contribute to stable CSF vaccine production and animal welfare.

Three bovine rotaviruses A (RVAs) isolated from a cattle farm in Japan were serotyped by serum neutralization assay, as compared with the RVA strains contained in a vaccine used on the same farm. Antisera were prepared against the three isolates and the vaccine strains of bovine RVA. The results of cross-neutralization tests revealed that the RVA isolates from this farm differed somewhat in serotype. Collected plasma from calves for 6 weeks after colostrum ingestion showed that maternal antibodies acquired against all isolates gradually decreased, but antibodies toward one isolate increased by 6 weeks after the mentioned decreasing. These results suggest that rotavirus vaccines administered to cows should include all serotypes commonly found in calves with diarrhea.

Lymphocytic choriomeningitis virus (LCMV) is a neglected rodent-borne zoonotic virus in the genus Mammarenavirus and family Arenaviridae, that can cause aseptic meningitis in humans. A recent study identified infectious LCMV in ticks in northeastern (NE) China. To explore the distribution of LCMV, we determined the prevalence and genetically characterized LCMV in ticks in Jilin Province, NE China. Ticks collected in Huadian, Dunhua, and Jiaohe were pooled and LCMV was detected using reverse transcription polymerase chain reaction. The complete genomes of the LCMV-positive pools were amplified and used for phylogenetic analysis. A total of 1679 questing and engorged ticks were collected and divided into 170 pools, including Ixodes persulcatus (5%), Dermacentor silvarum (89%), and Haemaphysalis japonica (6%). Twenty-four pools of D. silvarum (14.9%, 95% CI:9.5–22.3) and three pools of H. japonica (36.3%, 95% CI:9.8–99.5) collected from cattle were LCMV-positive. No I. persulcatus pools were identified as LCMV-positive. Two complete genome sequences (strains JL-DH01 and JL-DH02) were successfully amplified. They had nucleotide identities of 96.4–99.8% with strains JX31, JX14, DH46, and JX4 identified in ticks from Jilin Province. Phylogenetic analysis indicated that JL-DH01 and JL-DH02 clustered with Jilin strains in the same branch and belonged to genotype I. The findings add to the knowledge of the genetic diversity and geographical distribution of LCMV in ticks in NE China.

Feline leukemia virus (FeLV) is a retrovirus that causes immune suppression and immunodeficiency, leading to opportunistic infections and leukemia/lymphoma in cats. Today, a variety of domestic mammals are kept in houses, and it is important to evaluate the possibility of interspecies transmission of FeLV. In this study, we assessed the infectivity of FeLV-B in ferrets that belong to Mustelidae. By pseudotype virus infection assay, we revealed that a ferret cell line, Mpf cells, is resistant to FeLV-B infection. The mRNA expression level of the FeLV-B receptor, Pit-1, was approximately half that of cat FEA cells in ferret Mpf cells. There was no significant difference in receptor usage between ferret’s and cat’s Pit1. These data may indicate the presence of the post-transcriptional modification and/or the restriction factor(s) against the FeLV-B infection in ferrets.

Severe fever with thrombocytopenia syndrome virus (SFTSV) causes lethal hemorrhagic diseases in human, cats, and dogs. Several human cases involving direct transmission of SFTSV from diseased animals have been reported. Therefore, rapid diagnosis in veterinary clinics is important for preventing animal-to-human transmission. Previously, we developed a simplified reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay for human that does not require RNA extraction for detecting the SFTSV genome. In this study, we improved the simplified RT-LAMP assay for cats by introducing a dried reaction reagent and investigated the applicability of this method for diagnosing SFTS in cats. SFTSV RNA was detected in 11 of 12 cats naturally infected with SFTSV by RT-LAMP assay using both liquid and dried reagents. The RT-LAMP assay using liquid and dried reagents was also applicable to the detection of SFTSV genes 3–4 days after challenge in cats experimentally infected with SFTSV. The minimum copy number of SFTSV genes for 100% detection using the RT-LAMP assay with liquid and dried reagents was 4.3 × 10⁴ and 9.6 × 10⁴ copies/mL, respectively. Although the RT-LAMP assay using the dried reagent was less sensitive than that using the liquid reagent, it was sufficiently sensitive to detect SFTSV genes in cats with acute-phase SFTS. As the simplified RT-LAMP assay using a dried reagent enables detection of SFTSV genes more readily than the assay using a liquid reagent, it is applicable for use in veterinary clinics.

Previous studies on dolphin electrocardiograms have shown that they are mainly composed of increased negative waves, similar to ungulates. The electrocardiogram waveform was determined by the distribution of the Purkinje fibers. Based on the waveform of the dolphin electrocardiogram, Hamlin predicted that the Purkinje fibers would be distributed within the ventricular muscle, as in ungulates. The purpose of this study was to confirm the histological distribution of Purkinje fibers in dolphins. In the present study, bottlenose dolphin hearts were observed both grossly and histologically, and the effects of Purkinje fiber distribution and cardiac morphology on electrocardiogram waveforms were examined. This study showed that the Purkinje fibers of dolphins run just below the endocardium, as in humans, dogs, and cats, whose electrocardiograms mainly show positive waves. When the cardiac morphology of dolphins was observed carefully, the right ventricle was found to be extremely dilated compared to that of terrestrial mammals. In human recreational divers, right ventricular dilatation is induced by diving. We hypothesized that the dolphin’s heart is in a state similar to that of the right heart dilatation in terrestrial animals. The dolphin electrocardiogram waveform was considered to be due to right axis deviation. Based on the above, we concluded that the dolphin electrocardiogram waveform was due to its ability to live in water. We found that the dolphins are genetically related to ungulates, particularly the hippopotamus, but that their hearts have evolved differently.

We investigated the prevalence of porcine circovirus 2 (PCV2) and 3 (PCV3) in wild boars captured or found dead in Nagano Prefecture in 2020. Based on PCR testing, 21 of 254 (8.3%) wild boars were PCV2-positive and 43 of 256 (16.8%) wild boars were PCV3-positive, 5 of 253 (2.0%) wild boars were both PCV2-positive and PCV3-positive. The frequency of detecting PCV3 in wild boars was significantly higher in adults than in juveniles (P=0.014). The PCV2-positive wild boars were found in all districts except for the North Alps and Hokushin, while PCV3-positive wild boars were found in all districts except for Suwa. This is the first report of PCV2 and PCV3 detected in wild boars in Japan.