α-Hemolysin (α-Hly) is produced by pathogenic Escherichia coli and is implicated in a variety of diseases. In the swine, enterotoxigenic E. coli (ETEC) and Shiga toxin-producing E. coli (STEC) strains cause post-weaning diarrhea and edema disease, respectively, and most of these strains are hemolytic. However, the role of α-Hly in ETEC and STEC infection is unclear. Here, we prepared α-Hly-specific monoclonal antibodies by immunizing animals with one-third of the carboxy end of recombinant α-Hly. The four α-Hly-specific antibodies obtained reacted with α-Hly in the culture supernatant of clinical isolates in enzyme-linked immunosorbent assay and western blot analysis. In addition, because these four monoclonal antibodies inhibited E. coli-induced hemolysis, these antibodies might be useful tools for investigating the significance of α-Hly in pathogenic strains.

Pulmonary hypertension (PH) can affect renal function, yet renal dysfunction in canine PH is relatively underexplored. Cystatin C (CYS-C), a useful marker for evaluating renal function in humans with PH, has not been studied in dogs. This study aimed to compare seventeen dogs with PH to a control group, evaluating the relationship between PH and renal parameters such as symmetric dimethylarginine (SDMA), creatinine, and CYS-C. The mean tricuspid regurgitation maximal velocity (TRmax) and systolic pulmonary arterial pressure (SPAP) in dogs with PH was 4.24 m/sec and 74.48 mmHg, respectively. Dogs with PH exhibited significantly higher SDMA (15.47 μg/dL vs. 10.55 μg/dL) and CYS-C (1.36 mg/L vs. 0.88 mg/L) compared to controls. SDMA showed moderate positive correlations with SPAP (r=0.682) and TRmax (r=0.662), and a negative moderate correlation with mean arterial pressure (r=−0.590). CYS-C moderately correlated with SPAP (r=0.529), TRmax (r=0.485), heart rate (r=0.506), and body weight (r=0.691). Creatinine did not vary significantly between PH group (122.21 μmol/L) and controls (93.70 μmol/L), nor did it correlate with any parameters. Multivariate analysis revealed that CYS-C was significantly influenced by PH severity, while SDMA and creatinine were not. These findings suggest that renal dysfunction is prevalent in dogs with PH. CYS-C may be a more sensitive marker for detecting early renal changes linked to PH severity, while SDMA appears to be more specific to true renal dysfunction and creatinine was the least informative biomarker.

A 12-year-old castrated male Labrador Retriever presented with asymptomatic hypercalcemia. Based on elevated parathyroid hormone levels and an enlarged parathyroid gland, primary hyperparathyroidism was suspected, and parathyroidectomy was performed, but the hypercalcemia did not improve. Histopathology of three resected parathyroid glands revealed hyperplasia and hypertrophy of the principal cells. After surgery, the fractional excretion of calcium examined in a spot urine sample was close to that in healthy dogs, but lower than that in a dog with primary hyperparathyroidism. Autoantibodies against calcium-sensing receptor (CaSR) were confirmed by incubating a cell line expressing canine CaSR with a serum sample from the hypercalcemic dog. Our report is the first to describe the diagnosis of acquired hypocalciuric hypercalcemia in a dog.

Mycoplasma bovis (M. bovis) is an important bacterium in the bovine respiratory disease complex (BRDC), which causes significant economic losses. The nasopharyngeal and palatine tonsils are mucosal-associated lymphoid tissue components that are the initial barrier to respiratory pathogens. In the present study, we investigated 5 pneumonic Japanese black and 3 control calves (2 Japanese black and 1 Holstein). The localization of M. bovis in the nasopharyngeal, palatine tonsils, and lungs was examined using nested and multiplex polymerase chain reaction (PCR), histopathology, and in situ hybridization (ISH) techniques. Nested PCR revealed that all examined tissues from all pneumonic calves were positive for M. bovis infection, but not the control. Histopathology revealed suppurative nasopharyngeal tonsillitis and palatine tonsillar cryptitis in all cases. Surprisingly, prominent histologic changes were observed in the palatine tonsils but not in the nasopharyngeal tonsils. Necrotizing suppurative bronchopneumonia was observed in 4 pneumonic calves. In ISH analysis, positive hybridization signals adherent to and/or within the surface epithelium of nasopharyngeal tonsils and crypt epithelium of nasopharyngeal and palatine tonsils were observed. Additionally, these signals were seen in the palatine tonsillar cryptic detritus. In the lungs, ISH signals were observed in necrotic areas, the bronchial epithelium, and pulmonary inflammatory exudate. These findings suggest that the nasopharyngeal and palatine tonsils are the primary sites of M. bovis infection. Also, M. bovis can colonize the detritus in the crypts of the palatine tonsils of the pneumonic animals.

Autophagy is an intracellular degradation system that generates autophagosomes. Autophagy was investigated in rat hepatic lesions induced by a single intraperitoneal injection of D-galactosamine (D-GalN) that can induce hepatic lesions mimicking human viral hepatitis. Lesions consisting of hepatocyte necrosis were sporadically seen within hepatic lobules on post-injection days 1 and 2, and recovered on days 3 and 5. The number of LC3B-immunopositive cytoplasmic granules (autophagosomes) increased significantly in hepatocytes on days 1 and 2 with increased Toll-like Receptor-2 (TLR-2) mRNA. Interestingly, there were some abnormal autophagosomes with vacuolated or irregular structures, being related to decreased mRNA level of Lamp2 at 8 hr and on days 2–5. These results indicated that autophagy may participate in the development of D-GalN-induced rat acute liver lesions through its activation or degradation.

Hydrocephalus is a brain disorder in which cerebrospinal fluid accumulates in the ventricles. Our previous study identified aberrant α-smooth muscle actin (α-SMA) expression in the lateral ventricle lining of hydrocephalic coiled-coil domain containing 85c (Ccdc85c) mutant rats. Here, we investigate α-SMA expression in spontaneous hydrocephalic rat, dogs, cats, and cattle. Immunohistochemistry revealed distinct α-SMA expression in a hydrocephalic rat (3 weeks old) and cattle (9 months old), but not in dogs or cats, suggesting species-specific differences. Co-expression of α-SMA and vimentin was observed in cattle, along with strong glial fibrillary acidic protein (GFAP) and vimentin expression in rat and cattle, particularly in ependymal cells. These findings suggest that α-SMA expression in the lateral ventricle wall of hydrocephalic rat and cattle reflects a reactive or pathological response, potentially linked to gliosis.

Amyloid β (Aβ) deposition is a hallmark of Alzheimer’s disease. Humans and many animal species have identical Aβ amino acid sequences and develop senile plaques. Domestic and leopard cats have a unique Aβ sequence and show indistinct diffuse granular Aβ deposits in their brains. We aimed to elucidate whether these characteristics are conserved among Felidae species. The Aβ amino acid sequence and deposition pattern were conserved among Felidae species. Aβ deposits were also found in the cerebral vascular walls. Colocalization of apolipoprotein E and Aβ was observed in the parenchyma and cerebral vascular walls. These results support previous findings that a unique Aβ amino acid sequence may have a significant effect on the aggregation properties of this protein in Felidae.

Drug administration in avian species via the parenteral route tends to result in stress, as most often birds need to be handled and manipulated. The purpose of this study was to evaluate the potential of the transdermal administration route as an alternative for tramadol hydrochloride in avian. A total of 24 85-day-old broiler chickens were used as a model for avian species in this study. The chickens were divided into four equal groups of 6 animals each: i. Control, without intervention (C); ii. Intravenous at 5 mg/kg (IV); iii. Transdermal at 5 mg/kg (TD1); and iv. Transdermal at 10 mg/kg (TD2). The thermal antinociception effect was opted to simulate pain, by using a heating plate. The foot withdrawal response of each animal to a thermal stimulus was determined pre-administration (as baseline), followed by 30-, 60-, 120-, 240-, 360- and 480-min post-tramadol administration. All treatment groups showed significantly higher (P<0.05) foot withdrawal temperature threshold compared to the control group. Comparatively, there was a statistically significant higher temperature threshold than baseline at 60-, and 120-min post treatment for both TD1 and TD2 groups, while the IV group only at 60-min post treatment. Intravenous tramadol recorded the highest change in the foot withdrawal thermal threshold, while transdermal tramadol at 10 mg/kg recorded the longest effective time up to 240 min post-administration. This is the first study to evaluate the analgesic effectiveness of transdermal tramadol in avian, thus further investigation is required to confirm similar effects in other species.

Bovine amyloid A (AA) amyloidosis has been reported to be experimentally transmitted to mice, like prion disease. Although the prevalence of AA amyloidosis in cattle at slaughterhouses has been reported in several studies, how much bovine AA is distributed in retail stores remains unknown. In this study, to clarify the food hygienic risk of bovine AA, we collected beef livers from seven commercial retail stores in Japan to investigate the deposition rate and the transmissibility of bovine AA. Congo red staining and immunohistochemistry revealed bovine AA deposition in two of 185 commercial beef livers (1.08%). No differences were observed between the gross appearance of amyloid-laden and amyloid-free livers. Administration of bovine AA from commercial beef liver to mice, either intraperitoneally or into the spleen, did not promote the development of AA amyloidosis. This contrasts with previous studies demonstrating cross-species transmission of AA amyloidosis via intraperitoneal or even oral administration of bovine AA. Although the cause of this discrepancy is unknown, the low transmissibility may be related to the species-barrier. These results support that the actual food hygienic risk of AA amyloidosis associated with consuming commercial beef liver may not be significant.

A 9-year-old domestic short hair cat presented with a firm thoracic mass suspected to be a lipoma. Preoperative indocyanine green was administered intravenously at a dose of 5 mg/kg for short-wave infrared fluorescence imaging. Intraoperatively, a plaque-like lipoma overlaid a subjacent mass that exhibited strong fluorescence. Both were excised, and histopathology confirmed the subjacent mass as a well-differentiated liposarcoma. The cat recovered uneventfully with no recurrence at 11 months. This case highlights the utility of short-wave infrared fluorescence imaging in distinguishing benign from malignant tissues intraoperatively and enabling precise resection. To our knowledge, this is the first report of feline liposarcoma identified through short-wave infrared fluorescence imaging, demonstrating its potential as a valuable tool in veterinary oncology.

The contrast enhancement between gadoxetate disodium (Gd-EOB-DTPA) and gadodiamide hydrate (Gd-DTPA-BMA) in indirect magnetic resonance lymphography was compared among six healthy beagles. Contrast mediums (0.5 mmol) were injected subcutaneously into the lateral malleolus of the right fibula. Magnetic resonance imaging was performed at 5, 10, 15, 30, 45, and 60 min. The popliteal and medial iliac lymph nodes (LNs) were visualized. Gd-EOB-DTPA had a significantly superior contrast enhancement ratio than Gd-DTPA-BMA at 10 and 15 min at the popliteal LNs. Moreover, Gd-EOB-DTPA had a longer duration of contrast enhancement than Gd-DTPA-BMA in both the popliteal and medial iliac LNs. Gd-EOB-DTPA demonstrated stronger and longer-lasting lymph node enhancement than Gd-DTPA-BMA, thereby indicating its potential application in MR lymphography.

Progressive myelomalacia (PMM) is a severe neurological disorder. Although several case reports have been published, PMM is uncommon in cats. A 9-year-old neutered male domestic short-haired cat presented with hindlimb paraplegia. Based on the neurological examination, severe abnormalities in the L4-S3 segment were suspected. Based on magnetic resonance imaging findings, intervertebral disk herniation (IVDH) was suspected at the L5-L6 intervertebral disk. A hemilaminectomy and durotomy were performed. Four days after surgery, PMM was suspected, and the cat was euthanized. An autopsy was performed, and a histopathological examination confirmed PMM secondary to severe spinal disorders.

Felipivirus is a feline picornavirus that was first discovered in fecal samples from stray cats in Hong Kong in 2012, and has been reported only in a few cases. We previously reported next-generation sequencing (NGS) analyses of fecal samples from 20 adult cats in an animal shelter in Tokyo, Japan, and now, in this study, report detection of felipivirus A2 from the same samples. Reverse transcription (RT)-PCR demonstrated the presence of the same virus in the 8 cats. Phylogenetic analyzes demonstrated a close relationship of the virus with some picornaviruses from wild animals such as raccoon dog and marmot. This study highlights the importance of surveillance of cats in animal shelters to detect viruses potentially originated from wild animals.

Amenamevir (AMNV), a helicase-primase inhibitor, has recently received approval for treating human herpesvirus infections. Herein, we evaluated the efficacy of AMNV against feline herpesvirus 1 (FHV-1) in three different cell lines and compared it with that of acyclovir (ACV) and penciclovir (PCV)—nucleoside analogs currently used against FHV-1 infection. The 50% inhibitory concentrations of AMNV against FHV-1 were comparable to those of ACV in all cell lines tested, although they were 2.0 to 21.0-fold higher than those of PCV. This is the first study to have evaluated the efficacy of AMNV against animal herpesvirus, and the results suggest that AMNV could be a new option for treating FHV-1 infection with a novel mechanism of action.

This study investigates lead (Pb) contamination in wild animals in Japan. Pb is a known environmental toxin that can cause several issues in wildlife. Pb is still used in human society, and among Pb products, ammunition is reported to harm human and animal health. In Japan, few instances of Pb contamination in wild animals have been reported outside Hokkaido. Possible reasons for this include the absence of Pb contamination and insufficient investigation. This study aimed to understand the current state of Pb contamination in Japan and clarify the extent of Pb contamination related to ammunition. Blood lead concentrations (BLLs) were measured in wild birds and mammals from 25 municipalities, and an analysis was conducted based on ammunition-related factors. More than half of the avian and mammalian taxonomic groups were found to exhibit Pb contamination from environmental sources. Overall, this study suggests that Pb contamination is also present in wild birds and mammals living outside Hokkaido, Japan, and highlights the risks of mass mortality during infectious disease outbreaks as well as the potential health hazards of Pb exposure upon their consumption by humans. The results of this study highlight the importance of monitoring Pb contamination, particularly in hunting areas of Japan. Further, it indicates the need to reconsider the use of Pb-based ammunition for protecting the health and welfare of both humans and wildlife.

Red foxes living in urban areas are called “urban foxes,” and their numbers are increasing in Sapporo, northern Japan. Ecological features such as their food habits could have changed compared with foxes in rural areas. To investigate the diet of urban foxes, we developed a method for detecting mammalian prey species by non-invasive fecal DNA analysis. Target-specific PCR primers were designed for possible prey species, including eleven wild mammals and three livestock animals. Fox fecal samples (N=78) collected in Sapporo were surveyed for prey species. We detected the gray red-backed vole (which had been considered the principal prey species), chicken, and pig at high frequencies. The brown rat, a typical urban rodent, was also detected in some fecal samples from central Sapporo. The foxes in Sapporo frequently used foods characteristic of urban areas, including anthropogenic sources such as garbage.

Understanding of relationship between physiological condition and testicular function in captive cheetahs would be beneficial for their successful breeding and conservation. This study investigated the states of germ cells and Sertoli cells in three captive cheetahs with different ages and health conditions using histological methods. The disarrangement of Sertoli cells and germ cells in seminiferous tubules was shown in all individuals. Many Sertoli cells detached from the basal membrane suggesting the decreased blood testis barrier. Spermatogenesis was observed in two cheetahs, whereas the number of elongated spermatids was lower than in domestic cats. One old cheetah with long-term health problem had no spermatids. These findings would be useful basic information for improving the reproduction of cheetahs in zoos.

This study investigated the pathological and parasitological causes of death in two two-toed sloths (Choloepus didactylus) housed at a zoo in Hokkaido, Japan. Genomic DNA was extracted from the clotted blood of these animals and subsequently examined by nested PCR assays targeting the 18S rRNA and β-tubulin genes. The nucleotide sequences of these genes were determined and a phylogenetic analysis of the 18S rRNA gene was performed. One sample was detected positive in nested PCR. Sequencing analysis revealed that the detected parasite was closely related to the order Piroplasmida and was subsequently designated as Piroplasmida sp. Choloepus didactylus-1 (Piroplasmida sp. CD-1).