Assisted reproductive technologies (ARTs) are one reproductive strategy to support conservation efforts for species with decreasing populations. To develop these techniques, the variation of reproductive traits among animals must be considered for successful implementation. In artificial insemination (AI) or in vitro fertilization (IVF), semen collection using penile vibratory stimulation requires basic anatomical data of the penis. In the Sunda porcupine (Hystrix javanica), however, there is no such information. Therefore, in this study, anatomical and histological examinations of the penis of the Sunda porcupine were performed to provide baseline data that can be used for further studies to develop ARTs for this species. Six penes from euthanized wild adult male Sunda porcupines obtained in Central Java, Indonesia, were utilized in this study. Characteristically, the penis of the Sunda porcupine had a sacculus urethralis and glans penis with penile spines, which demonstrated regional structural differences, and the os penis was capped by a cartilaginous structure. The distribution pattern of the penile spines may be useful for mechanical reproductive procedures such as efficient vaginal and penile stimulation. Immunohistochemically, androgen receptors (AR) were localized in the epithelial cells of the surface of the glans penis and sacculus urethralis, and may play a role in the maintenance of the keratinized penile spines.

An indirect and a sandwich enzyme-linked immunosorbent assay (ELISA), employing long-chain lipopolysaccharides (LC-LPS) and crude boiled extract as antigens respectively, were evaluated for the detection of antibodies against Actinobacillus pleuropneumoniae serovars 1, 2, 5, 9 and 11 in pig sera. By testing sera from pigs experimentally infected with the 10 recognized serovars, both assays were proven to have comparable sensitivity and specificity. With sera from pigs immunized with vaccines containing antigens of A. pleuropneumoniae serovars 1, 2 and 5, the assays were found to have a good correlation. The high diagnostic sensitivity and specificity of the indirect ELISA, along with its efficiency and ease of standardization—especially when using well-characterized antigens such as LC-LPS—may make it a valuable tool for field diagnostics.

Foot-and-mouth disease (FMD) is a highly contagious transboundary animal disease causing major economic losses worldwide. This study aimed to establish baseline serological data for FMD in cattle from an FMD-free region of Indonesia using a non-structural protein (NSP) antibody lateral flow assay and to evaluate diagnostic interpretation in a low-prevalence setting. A total of 218 serum samples were collected in East Nusa Tenggara Province. Six samples (2.75%) tested positive, 211 (96.79%) were negative, and one was invalid. The apparent prevalence was 2.75% (95% CI: 1.01–5.90%). Adjusted true prevalence using the Rogan–Gladen estimator was 0%, indicating no detectable infection within the study population rather than definitive absence of infection. Considering assay specificity (96.46%), the observed positives are consistent with expected false-positive results. No clinical signs were observed. These findings suggest no evidence of active FMD circulation within the limits of the study and highlight the importance of cautious interpretation of serological data in low-prevalence settings.

Transboundary diseases, such as African swine fever, pose significant threats to the Japanese swine industry, making robust biosecurity essential. However, established assessment tools quantify overall biosecurity levels, and the specific practices driving performance variation among farms remain unclear. This study applied machine learning algorithms to identify key biosecurity measures distinguishing high-performing farms. Total, external, internal, and diagnostic monitoring scores from 254 records of the biosecurity assessment tool (2014–2023) were analyzed using Random Forest models coupled with Boruta feature selection, incorporating the assessment year to adjust for temporal shifts. The models demonstrated robust predictive accuracy (R²=0.83–0.93 for total, external, internal, and diagnostic monitoring scores). The analysis identified the rigorous management of high-risk external interfaces—specifically, visitor shower-in requirements, strict entry criteria, and the use of exclusive slaughter transport vehicles—as primary determinants of farm-to-farm variation. For internal biosecurity, controlling access to shared spaces like break rooms, alongside segregating production stages via clothing and boot exchanges, emerged as key differentiators. Notably, overall and diagnostic monitoring scores were strongly driven by the “software” of biosecurity—specifically, the strict maintenance of implementation records (e.g., for vermin control and disinfection) and adherence to sampling manuals. These findings suggest that biosecurity variation in Japan is defined by the integration of robust physical barriers with highly systematized, verifiable management protocols. To elevate the national biosecurity baseline, stakeholders should prioritize investments in external risk interfaces and the rigorous documentation of daily practices.

Johne’s disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP), imposes major economic burdens on dairy production. Japan’s legally mandated surveillance includes regular surveillance (RS) every 5 years in MAP-negative herds and follow-up surveillance (FS) in MAP-positive herds, consisting of 5 tests over 3 years. However, the effectiveness and cost-effectiveness of this program have not been quantitatively assessed. We developed a stochastic, individual-based simulation model to evaluate MAP transmission, farm-level economic impacts, and government costs in dairy herds in Hokkaido, Japan’s largest dairy-producing region. Eight scenarios were compared: no surveillance, the current program, and variations in RS interval, FS duration, and FS testing frequency. Results indicated that, compared with no surveillance, the current program slowed the increase in within-herd prevalence and increased the probability of MAP fade-out, thereby reducing economic losses. Shortening the RS interval to 3 years enhanced early detection and more efficiently achieved MAP fade-out, which in turn reduced government costs. Compared with the current program, shortening FS duration or reducing testing frequency lowered detection efficiency of the surveillance program and increased MAP persistence, while extending duration or increasing frequency provided little additional benefit. Overall, the current JD surveillance program in Hokkaido effectively promotes MAP fade-out within herds through early detection by RS combined with repeated high-frequency FS testing, although a shorter RS interval may further strengthen early detection and JD control.

In April 2020, an outbreak of diarrhea occurred in lactating cows at a dairy farm in the Tottori Prefecture. Five cows died, and Listeria monocytogenes was isolated from the liver, spleen, kidney, and jejunum of one affected cow that was subjected to bacteriological examination. Pathological examination revealed liver necrosis. Histopathologically, the primary lesions were characterized by multifocal necrotizing hepatitis. Small bacilli were immunohistochemically identified within the necrotic hepatic lesions, as well as the jejunal villi and central lacteals. The diagnosis was confirmed as septicemic bovine listeriosis. Subsequently, five L. monocytogenes-suspected abortions and multiple cases of mastitis occurred on the farm. The L. monocytogenes strains isolated from the affected cow and the abortion and mastitis cases were all serotype 4b; their sequence type, determined by multi-locus sequence typing, was ST1, and their clonal complexes were CC1. This case was considered an extremely rare outbreak in which the same strain of L. monocytogenes caused diverse symptoms, such as septicemia and diarrhea.

A 12-year-old Beagle dog with generalized lymphadenopathy and persistent neutropenia was diagnosed with advanced marginal zone lymphoma based on cytology, histopathology, and polymerase chain reaction for antigen receptor rearrangement analysis. Bone marrow examination revealed hypocellularity predominantly affecting the myeloid lineage, while normal morphology and maturation were preserved across hematopoietic lineages, with no evidence of myelophthisis or fibrosis. Chemotherapy was initiated using a modified and dose-reduced multi-agent protocol, followed by L-asparaginase and nimustine; full-dose chemotherapy was also subsequently tolerated without serious adverse events. Two complete remissions were achieved during the treatment course. Normalization of the neutrophil count during tumor progression was presumed to reflect increased neutrophil demand associated with disease progression, indicating that compensatory hematopoietic capacity was preserved. This case illustrates that, in dogs with persistent neutropenia and myeloid hypoplasia, chemotherapy may be considered when bone marrow evaluation confirms preserved hematopoietic maturation and careful monitoring is performed.

Circulating tumor DNA (ctDNA) consists of genomic DNA fragments shed by tumor cells into the bloodstream that contain the same mutations present in the primary tumor. In human medicine, ctDNA has been utilized as a liquid biopsy tool and a noninvasive biomarker for the early diagnosis, prognosis, and management of several tumors. This study explored the utility of ctDNA monitoring using digital polymerase chain reaction (dPCR) during follow-up in two dogs with oral malignant melanoma. Whole-exome sequencing was performed to identify patient-specific tumor mutations, and dPCR probes designed for these mutations were then used to measure ctDNA levels in plasma samples obtained during follow-up. In two patients, ctDNAs were detected at the time of diagnosis, and in one patient, complete remission was attained via radiation; the disappearance of ctDNA was observed, followed by a re-elevation, indicating lymph node metastasis. In another patient in whom radiation therapy was ineffective, persistent ctDNA was noted during follow-up. To the best of our knowledge, this is the first study to identify patient-specific somatic mutations and monitor ctDNA using dPCR.

Gastric neuroendocrine neoplasms (NENs), historically termed gastric carcinoids, are rare in dogs and poorly characterized in veterinary medicine. A 13-year-old spayed female Maltese dog was evaluated for an incidentally detected abdominal mass. Computed tomography revealed a contrast-enhancing gastric body mass and an enlarged regional lymph node suspicious for metastasis. Surgical excision and histopathology confirmed a well-differentiated gastric NEN with regional lymph node metastasis. Immunohistochemical findings supported neuroendocrine differentiation and helped exclude major differential diagnoses. Despite relatively low mitotic activity and a relatively high proliferative index, metastatic spread was documented. This case highlights that histologically well-differentiated canine gastric NENs may exhibit malignant behavior and emphasizes the importance of thorough nodal assessment for accurate staging.

Cutaneous and subcutaneous soft tissue sarcomas of undetermined differentiation are common in pet rabbits and are often diagnosed as sarcoma not otherwise specified (sarcoma NOS). Such sarcomas with marked cellular pleomorphism and presence of multinucleated giant cells are also referred to as undifferentiated pleomorphic sarcoma, anaplastic sarcoma, or giant cell sarcoma. However, these terminologies do not define any cellular differentiation. In this study, we aimed to identify the line of differentiation of cutaneous pleomorphic sarcomas in rabbits. Histopathological, histochemical, and immunohistochemical analyses were performed on 48 cutaneous masses in rabbits, previously diagnosed as sarcoma NOS. Histologically, the tumors were characterized by proliferation of pleomorphic mesenchymal cells, primarily spindle cells, with frequent presence of multinucleated giant cells (58% of the cases). Sirius red staining revealed fine collagen fibers directly extending from the neoplastic cells in all cases. Some cases showed immunoreactivity for calponin (35%), α-smooth muscle actin (31%), and pan-muscle actin (25%). Almost all the case were negative for SOX10, ionized calcium binding adapter molecule-1 and CD204. Based on the findings above, rabbit cutaneous pleomorphic sarcomas are considered to differentiate towards fibroblasts and myofibroblasts. In addition, our follow-up data revealed a high recurrence rate and short survival times, indicating aggressive biological behavior of rabbit cutaneous pleomorphic sarcomas.

Oral epithelial dysplasia (OED) is a precancerous lesion of oral squamous cell carcinoma (SCC) in humans, characterized by decreased cytokeratin (CK) 13 expression, de novo CK17 expression, and increased Ki-67 expression. This study investigated the histopathological and immunohistochemical features of pericancerous epithelium (PCE) in lingual SCCs of dogs (n=14) and cats (n=8). PCEs were classified as high-grade or low-grade OED based on the human World Health Organization criteria. High-grade OED exhibited decreased CK13 expression, increased CK17 expression, and Ki-67 expression, resembling human high-grade OED. Morphological analysis revealed sharply demarcated lesions with drop-shaped rete processes and irregular epithelial stratification. These findings suggest that OED in canine and feline PCE shares key characteristics with human high-grade OED, supporting the presence of field cancerization in the oral mucosa of domestic animals.

Pulmonary botryomycosis is an extremely rare bacterial infection that has not been previously documented in cats. This report describes a case of pulmonary botryomycosis in a 10-year-old spayed female domestic shorthair cat with chronic pulmonary lesions refractory to long-term corticosteroid therapy. Surgical lobectomy of the right cranial and middle lung lobes was performed. Histopathological examination revealed extensive necrotizing and fibrosing pyogranulomatous inflammation with characteristic club colonies composed of Gram-positive cocci surrounded by eosinophilic Splendore–Hoeppli material. On molecular analysis of formalin-fixed, paraffin-embedded tissue, the highest 16S rDNA sequence homology was Staphylococcus spp. This case represents the first documented instance of pulmonary botryomycosis in a cat and highlights the diagnostic importance of combining histopathological and molecular approaches.

Infection with Marek’s disease virus (MDV) primarily causes neurological disorders and lymphomas; however, vascular syndrome rarely occurs. We herein report two cases of Japanese bantams submitted for a pathological examination, with multiple atherosclerotic lesions observed in the muscular arteries throughout the body. In the first case, diffuse proliferative lesions of neoplastic lymphocytes were formed in the spleen and liver and were considered Marek’s disease (MD) with vascular syndrome. In contrast, in the second case, no obvious diffuse proliferative lesions of neoplastic lymphocytes were observed. Viral proteins expressed upon MDV infection, such as MDV-EcoRI-Q (Meq) and phosphoprotein 38 (pp38), were detected by immunohistochemical staining, confirming that vascular syndrome can occur with MDV infection, regardless of the presence of diffuse proliferation of neoplastic lymphocytes characteristic of MD. In addition, it was confirmed that MDV-infected lymphocytes infiltrated the arterial lesions, and viral proteins were observed in the smooth muscle cells of the arterial lesions, suggesting that the infected lymphocytes may be transporting MDV to the arterial lesion sites.

Serum nonspecific esterases, including paraoxonase 1 (PON1), butyrylcholinesterase (BChE), and carboxylesterase (CES), may influence the hydrolysis of some ester-containing drugs. However, data on these enzymes across animal species remain limited. This study compared serum PON1, BChE, and CES activities among dogs (n=6), cats (n=6), micro-mini pigs (n=6), and goats (n=8) using identical assay systems. Serum samples were analyzed using established colorimetric or fluorescent assays, and interspecies differences were evaluated using the Steel–Dwass test. PON1 activity was highest in goats, BChE activity was highest in dogs, and CES activity was highest in cats. These findings demonstrate distinct interspecies profiles of serum nonspecific esterase activities and provide baseline data for future studies investigating species differences in the metabolism of ester-containing compounds.

We aimed to investigate the mechanical properties of canine long bones treated with liquid nitrogen for limb-sparing surgery (LSS) as described by Tsuchiya et al. Three-point bending tests were performed on left and right femurs and tibias obtained from healthy beagle cadavers to evaluate the bone mechanical properties. There were no significant differences in mechanical properties between the left and right bones from the same individual. Furthermore, none of the indices differed between liquid nitrogen-treated and untreated bones. Our findings suggest that liquid nitrogen treatment does not result in marked changes in the mechanical properties of canine long bones, and may provide basic mechanical information potentially relevant to LSS using liquid nitrogen-treated autografts.

A 4-year-old spayed female beagle presented with intermittent lameness and external rotation of the left hind limb after distal femoral fracture repair. Imaging revealed severe lateral trochlear deformity with complex deformities of the left femur. Trochlear ridge reconstruction and corrective osteotomy were performed using patient-specific titanium trochlear ridge implant and 3D-printed surgical guides. Postoperative images confirmed the proper femoral alignment and patellar positioning. The lameness resolved, and full weight-bearing was achieved within two months. Normal limb function was maintained for 24 months without implant failure or recurrence. At the 36-month telephone follow-up, the owner reported sustained improvement in limb function and quality of life. This case demonstrates successful long-term outcomes of trochlear ridge reconstruction using a patient-specific 3D-printed titanium implant.

Fipronil (FPN), a phenylpyrazole pesticide widely used in agriculture and households, acts as a noncompetitive antagonist of gamma-aminobutyric acid (GABA)-gated chloride channels. Although originally considered relatively safe for mammals at low doses, FPN is metabolized into fipronil sulfone (FPNS), a more toxic and persistent metabolite. Both FPN and FPNS have been detected in human biological samples, raising concerns about chronic exposure during critical developmental windows. In this study, pregnant mice were administered FPN orally at 0.43 mg/kg/day from gestational day 1.5 through weaning. In Experiment 1, which was designed to evaluate fetal transfer, FPN and FPNS were detected in all fetal samples, with FPNS concentrations exceeding those of FPN and the levels of both compounds being higher in fetuses than in dams, suggesting placental transfer and fetal accumulation. In Experiment 2, behavioral and endocrine effects were assessed in male offspring at 3 and 10 weeks of age. Behavioral tests included the open field, elevated plus maze, and novel object recognition test. FPN-exposed offspring exhibited increased locomotor activity, reduced anxiety-like behavior, and impaired short-term memory and object recognition. Blood analyses revealed the presence of FPN and FPNS in exposed offspring, with FPNS levels peaking at 3 weeks. Histamine and progesterone levels were elevated at 3 weeks, while progesterone and 17-hydroxyprogesterone levels were decreased at 10 weeks. These findings suggest that fetal and neonatal exposure to FPN can disrupt neurobehavioral and endocrine development in mice.

Interspecies differences in sensitivity to anticoagulant compounds remain an important issue in veterinary toxicology and wildlife risk assessment. In the present study, we developed an integrated pharmacokinetic–pharmacodynamic (PK/PD) model to quantitatively compare anticoagulant responses between rats and bats, linking hepatic exposure to vitamin K epoxide reductase (VKOR) inhibition and subsequent changes in prothrombin time–international normalized ratio (PT-INR). Species-specific pharmacokinetic parameters were estimated from experimental concentration–time data and incorporated into a mechanistic turnover model describing VKOR activity and clotting factor synthesis. The model reproduced dose-dependent PT-INR prolongation in rats and successfully described the delayed and attenuated anticoagulant responses observed in bats. Sensitivity analyses identified hepatic clearance (CLh), hepatic distribution volume (Vh), and the half-maximal inhibitory concentration for VKOR (IC₅₀) as key determinants of PT-INR responses, with a smaller contribution from baseline coagulation turnover. In addition, structure-based binding affinity estimates were explored as surrogate indicators of inhibitory potency. Although computational affinity scores qualitatively reflected relative anticoagulant strength, substituting these scores for experimentally derived inhibitory parameters reduced predictive accuracy in some resistant species, highlighting the current limitations of structure-only approaches. These findings demonstrate that mechanistic PK/PD integration provides a quantitative framework for evaluating species differences in anticoagulant toxicity and may support veterinary risk assessment and wildlife protection strategies.

This review systematically summarizes the development and applications of Simian-Human Immunodeficiency Virus (SHIV) models in rhesus macaques conducted by our research group from 2001 to 2023. Over this two-decade span, we have made significant contributions to HIV/AIDS research through the development and characterization of various SHIV models. Beginning with the isolation and characterization of molecular clones with different pathogenicities from SHIV-89.6P, we progressed to investigating the mechanisms of small intestinal CD4+ T cell depletion in SHIV infection. Subsequently, we developed R5-tropic SHIV models that better mimic natural HIV infection and conducted in-depth studies on neutralizing antibody induction and neutralization resistance. This review examines these research achievements chronologically, discusses their significance in understanding HIV/AIDS pathogenesis, and presents future research prospects in this field. Our findings have contributed substantially to elucidating the molecular mechanisms of HIV pathogenicity and establishing platforms for vaccine and therapeutic development.

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne zoonotic pathogen of increasing concern in East Asia, including Japan. Not only humans but also domestic cats are highly susceptible and frequently develop severe disease. Despite its public and veterinary health significance, data on the environmental stability of SFTSV remain limited. In this study, we evaluated the stability profiles of SFTSV under various temperature and inactivation conditions. As comparative controls, Kabuto Mountain virus (KAMV) which belongs to the same class and order as SFTSV, Japanese Encephalitis virus (JEV) representing a different type of enveloped virus, and Feline Calicivirus (FCV) representing an example of non-enveloped virus, were also tested. SFTSV showed higher infectious stability at 4°C, 23°C and 37°C compared to KAMV, JEV and FCV. In addition, SFTSV demonstrated comparatively higher resistance to heat inactivation at 56°C and 94°C. On the other hand, SFTSV was easily inactivated by ethanol, hypochlorite and ultraviolet irradiation. These findings provide important insights into the environmental persistence and inactivation requirements of SFTSV, suggesting that appropriate inactivation procedures are important to reduce the risk of SFTSV infection from the contaminated samples at clinical sites and laboratories.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses an ongoing public health concern, and its zoonotic nature increases the risk of cross-species transmission between humans and animals. Non-human primates (NHPs) are particularly susceptible because of the high similarity in angiotensin-converting enzyme 2 (ACE2) critical residues compared to those in humans, especially among catarrhine species. Therefore, surveillance of NHP populations is essential, particularly in Indonesia, a megadiverse nation hosting numerous primate species that frequently interact with humans. In this study, 237 NHPs representing multiple species, including long-tailed macaques (Macaca fascicularis), langurs (Trachypithecus spp.), gibbons (Hylobates spp.), and orangutans (Pongo pygmaeus), were sampled from both in-situ and ex-situ conservation settings across five provinces (Bali, East Java, West Java, Central Kalimantan, and West Sumatra). Paired nasopharyngeal and oropharyngeal swabs were tested for SARS-CoV-2 RNA using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). No molecular evidence of active SARS-CoV-2 infection was detected in any of the individuals sampled. None of the samples showed amplification of either the N1 or N2 gene targets, and no borderline Ct values (all Ct >35 or undetermined) or single-target reactivity was observed. These findings highlight the importance of ongoing surveillance of Indonesian NHP populations by expanding geographical coverage, increasing the sample sizes, incorporating serological testing, and evaluating additional sample types to better assess potential spillover and spillback risks.

Canine distemper virus (CDV) is a highly contagious, multi-host pathogen that spreads readily among susceptible animals and often causes mass mortality. Yanbian Prefecture, located at the border area of China, Russia, and North Korea, represents a critical region for pathogen surveillance due to its unique geographical characteristics and animal trade activities; however, little is known about the prevalent CDV strains in this area or their pathogenic mechanisms. In this study, a CDV strain, designated CDV-Yanbian (CDV-YB), was successfully isolated from an anal swab sample collected from a suspected infected dog in Yanbian Prefecture and identified as the Asia-1 genotype through genetic analysis. To further elucidate the molecular mechanisms underlying CDV-host interactions, we examined the expression changes of inflammation-related signaling pathway genes and the occurrence of pyroptosis in canine adipose-derived mesenchymal stem cells (ADMSCs) following CDV infection using RT-qPCR and Western blot. Our results revealed that CDV infection activated the Janus kinase 2-Signal transducer and activator of transcription 3 (JAK2-STAT3), mitogen-activated protein kinase (MAPK), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and phosphatidylinositol 3-kinase-Akt (PI3K-Akt) pathways and upregulated NLR family pyrin domain containing 3 (NLRP3) inflammasome activation. Furthermore, inhibition of the JAK2-STAT3 pathway using AG490 reduced NLRP3 inflammasome activation. Taken together, our findings demonstrate that CDV activates multiple inflammatory signaling pathways and, via the JAK2-STAT3 pathway, upregulates NLRP3 inflammasome activation in host cells, and pyroptosis was also observed. These findings provide a foundation for understanding CDV pathogenesis and informing future research on this important virus.

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tick-borne zoonotic virus endemic to western Japan. Miyazaki and Oita Prefectures are neighboring regions on Kyushu Island; however, the total number of reported human SFTS cases in 2013–2025 was nearly double in Miyazaki compared with Oita. To assess whether this difference is reflected in wildlife, we conducted a serological and molecular survey of SFTSV infection in wild boars. A total of 1,506 serum samples collected between November 2022 and May 2025 were analyzed by enzyme-linked immunosorbent assay (ELISA) and screened for viral RNA using quantitative reverse transcription PCR (qRT-PCR). The ELISA positivity rate was significantly higher in Miyazaki (34.1%, n=1,045) than in Oita (11.9%, n=461) (P<0.001). A randomly selected subset of 150 samples was also examined by an 80% plaque reduction neutralization test (PRNT₈₀). In contrast, although both the PRNT₈₀ positivity rate (44.2%, n=104 vs. 37.0%, n=46) and the viral RNA detection rate (0.57%, n=1,045 vs. 0%, n=461) were higher in Miyazaki, neither difference reached statistical significance. Furthermore, regional differences in ELISA seropositivity within each prefecture broadly corresponded with the distribution of human SFTS cases, suggesting that ELISA-based surveillance in wild boars may be useful for assessing broad regional patterns of SFTSV transmission.

Radiopaque intestinal calculi are occasionally observed in pet cockatiels. When large calculi are suspected of causing intestinal obstruction, medical therapy is unlikely to improve the condition, making surgical removal the appropriate treatment. However, surgical intervention is problematic owing to its high invasiveness. Recently, numerous human studies have demonstrated the efficacy of oral cola therapy for various gastrointestinal calculi. Here, we report a case of ileus in a cockatiel due to a large small-intestinal calculus, in which oral cola therapy achieved remarkable success.

Pulmonary aspergillosis is a fatal disease with high mortality in captive penguins in zoos and aquariums; however, antemortem identification of Aspergillus spp. remains challenging. A gentoo penguin (Pygoscelis papua) exhibiting respiratory clinical signs showed fluid accumulation in the interclavicular air sac on computed tomography (CT). The fluid was aspirated via puncture using a sterile needle in the prone position, as during CT. The fluid sample was positive for A. fumigatus in fungal culture. After the penguin died, infection of A. fumigatus was confirmed in the air sac fluid collected postmortem pathological examination. These findings suggest that combining computed tomography and air sac aspiration is a promising approach for the antemortem diagnosis of aspergillosis in penguins.

A 19-year-old male sea otter (Enhydra lutris) exhibited systemic seizures, declining consciousness, temporary cardiopulmonary arrest, and right-side rotation. The sea otter died approximately one month after its initial seizure. Postmortem magnetic resonance imaging examination revealed a high-intensity region in the left frontal lobe. At necropsy, a gelatinous lesion in the left frontal lobe of the brain was revealed. Histopathologically, the lesion consisted of neoplastic proliferation of round to polyhedral monomorphic cells with a honeycomb growth pattern, small round nuclei, and cytoplasmic halos. The neoplastic cells were immunopositive for oligodendrocyte transcriptional factor-2 (OLIG2) and immunonegative for glial fibrillary acidic protein (GFAP). In this study, we describe the clinical signs and histopathological features of oligodendroglioma, which have rarely been reported in sea otters.

Various patterns of the relationship between the musculocutaneous and median nerves have been reported. This is the first report in Canidae, a Japanese raccoon dog, of the musculocutaneous nerve fused into the median nerve in the brachial plexus. The musculocutaneous nerve gave rise to the only branch to the coracobrachialis muscle and fused into the median nerve. The median nerve sent a branch to the biceps brachii muscle, the medial antebrachial cutaneous nerve, and a branch to the brachialis muscle. This case report may provide clues to understanding the phylogeny and embryology of the brachial plexus in Canidae.

The rock hyrax (Procavia capensis) is a small herbivorous mammal, and reports on gastrointestinal disease in this species are limited. Here, we describe the case of a 3-year-old female with intermittent anorexia. Computed tomography revealed a high-attenuation structure in the cecum, which gradually increased in size over time, as confirmed by serial radiography. Exploratory laparotomy was performed, and a multilobulated enterolith primarily composed of magnesium ammonium phosphate was surgically removed. The animal recovered without complications, and all clinical signs resolved. This is the first detailed report of enterolithiasis in a rock hyrax, emphasizing the importance of considering this condition in the differential diagnosis of gastrointestinal symptoms and demonstrating that surgical removal is an effective treatment option.