Journal of Veterinary Medical Science最新文献

Bovine mastitis is an inflammatory disease of the udder caused by pathogen infection. In case of aerobic cultivation, 30% of milk samples have nonbacterial; this may relate to anaerobic bacteria, although this remains unclear. This study analyzed 173 mastitis milk samples collected via aerobic and anaerobic cultivation. The detection rate by anaerobic culture was significantly higher (P<0.01; 136 samples: 78.6%) than that by aerobic culture (125 samples: 72.3%). Furthermore, the detection rates of Streptococcus dysgalactiae, Streptococcus uberis, and Trueperella pyogenes were higher in anaerobic than aerobic culture. Clostridium perfringens was detected one sample (0.61%) and Fusobacterium necrophorum in two samples (1.22%) were detected. Overall, these findings indicated the value of anaerobic culture for detecting the causative bacteria of mastitis.

Canine urothelial carcinoma (cUC) is an aggressive malignancy, yet clinically accessible and reliable prognostic markers remain limited. While systemic inflammatory responses are increasingly recognized as critical determinants of cancer progression in humans, the prognostic value of white blood cell fractions in cUC remains unexplored. This retrospective cohort study investigated the association between white blood cell fractions and survival in 86 dogs with urothelial carcinoma (cUC) diagnosed at a university-affiliated veterinary hospital between 2017 and 2024. Case assignment, presence of metastases, the extent of urinary tract involvement, treatment specifics, and complete blood count (CBC) data were extracted from electronic medical records. CBC analysis revealed neutropenia in 3 cases, monocytosis in 7 cases, eosinophilia in 4 cases, and lymphopenia in 19 cases. Due to limited case numbers, survival analyses focused on monocytosis and lymphopenia, with calculation of the monocyte-lymphocyte ratio (MLR). Log-rank tests demonstrated significant associations between shortened overall survival and monocytosis, lymphopenia, increased MLR, and metastasis (P=0.0050, P=0.0097, P<0.0001, P=0.0125, respectively.). Multivariate analysis identified two independent predictors of shortened survival: increased MLR (hazard ratio [HR] 3.10, 95% confidence interval [CI] 1.90-8.81, P=0.0003) and metastasis (HR 2.86, 95% CI 1.32-6.15, P=0.0075). These findings suggest that MLR, a readily available parameter from routine CBC testing has the potential to serve as a practical and clinically informative biomarker in cUC.

Aortic thrombotic disease occurs in both dogs and cats. In dogs, it typically presents as aortic thrombosis (ATh), whereas in cats, it most commonly manifests as aortic thromboembolism (ATE). Canine ATh is rare, with no standardized treatment. Rivaroxaban, a direct factor Xa inhibitor, is increasingly used in veterinary medicine. Recently, the efficacy of dual antithrombotic therapy with clopidogrel and rivaroxaban in feline ATE has been suggested. Here, we report two canine ATh cases. Clopidogrel monotherapy was insufficient, but adding rivaroxaban improved gait, relieved pain, and reduced thrombus size on ultrasonography. This combination therapy may be effective for canine ATh, as has been suggested for feline ATE. Further case studies are needed to evaluate the efficacy of rivaroxaban for canine ATh.

Bovine adenovirus type 10 (BAdV-10) was isolated for the first time in Japan from a calf with severe hemorrhagic diarrhea at a farm in Gifu Prefecture. Histopathologically, lesions were mainly in the colon, with pseudomembrane formation accompanied by extensive fibrosis and viral inclusion bodies in the nuclei of vascular endothelial cells. The isolated virus showed cytopathic effect in bovine testicular cells and was genetically confirmed to be BAdV-10. Although the BAdV-10 gene was not detected in the rectal stools of cohabiting calves, an increase in antibody titers was observed. Involvement of BAdV-10 in lesion formation was suspected, but extensive fibrosis was not reported overseas. Further investigation is needed to clarify the prevalence and epidemiological significance of BAdV-10 in Japan.

Ticks are major public health vectors that rely on long-term extravascular feeding, a process critically dependent on establishing a subcutaneous blood pool. While tick salivary molecules suppress host hemostasis and immunity, the precise mechanism by which vascular integrity is compromised to sustain massive hemorrhage in the deep dermis, outside the tick hypostome's reach, remains a longstanding enigma. Using time-series pathological and multiplex immunohistochemical analyses in a mouse model infected with Haemaphysalis longicornis tick, we redefined the blood pool not as a cystic reservoir, but as a severe inflammatory lesion characterized by massive, diffuse extravasation of red blood cells. We observed that ticks induce pathological angiogenesis, forming fragile microvessels. Crucially, the formation of neutrophil extracellular traps (NETs), known as NETosis surged in clustering neutrophils on Day 3 of feeding, coinciding with the transition to massive hemorrhage. Furthermore, extravasated platelets co-localized with NETs in the hemorrhagic tissue. We propose a sophisticated parasitic strategy, whereby the tick hijacks host immunothrombosis to mediate massive hemorrhage. The dysregulated interaction between NETs and platelets drives a vicious inflammatory cycle, which destroys the fragile, newly formed vasculature and extracellular matrix. This process establishes a blood-soaked, sponge-like stroma, which the tick exploits for efficient blood intake. Our findings redefine the fundamental mechanism of tick feeding success.

Surgical treatment options for feline ureteral obstruction are lacking. Based on its use in human medicine, tamsulosin may be a promising candidate. We have accumulated evidence of its extra-label use at our hospital in cases where surgery was declined by the owner. Accordingly, in this single-center, retrospective study, we investigated the responses to tamsulosin in patients with multi-causal feline ureteral obstruction by determining response rates and evaluating the demographic and clinicopathological characteristics of responders. Cats were classified as responders if they showed complete or partial hydronephrosis remission (renal pelvic diameter <50% of the presentation value). We evaluated 62 cats, of which 32 had ureteral calculi (51.6%) and 30 (48.4%) did not. All cats had received 50 μg oral tamsulosin once daily as initial treatment. A total of 30/62 (48.4%) cats were defined as responders, and the response rates were similar irrespective of the presence or absence of ureteral calculi. Body weight was significantly higher in responders than in non-responders. Adverse drug reactions were rare, mild, reversible, and did not include hypotension.The response rate we report for tamsulosin may be of interest to clinicians considering its use in combination therapy where surgery is declined or delayed and for future research on feline ureteral obstruction.

The Japanese rock ptarmigan (Lagopus muta japonica) is an endangered alpine bird endemic to Japan. Wild individuals mainly consume leaves, flowers, and fruits of dwarf shrubs, but captive-reared birds often fail to adapt due to altered cecal microbiota. The bacterial genera Synergistes, Olsenella, and Megasphaera are typical in wild ceca. To restore these communities in captivity, chicks were fed alpine plants and freeze-dried cecal feces from wild birds. We developed a real-time PCR method to quantify these genera. While Synergistes was not fully restored, Olsenella and Megasphaera populations were successfully established. This method provides a practical tool to evaluate feeding strategies and supports the production of release-ready chicks from captive populations.

Forty male brown bear heads were non-destructively analyzed by computed tomography. Skull, frontal, and cranial cavity volumes were measured, and growth curves and regression lines were constructed. The morphological dynamics of the frontal sinus were also examined. Skull volume increased rapidly from 0 to 11 years of age, then grew more slowly until 21 years, when it plateaued. The frontal sinus also increased rapidly from 0 years, reaching approximately 300 mL by 10 years, after which growth ceased. The frontal sinus-to-skull ratio rose quickly from 0 to 4 years, then increased more gradually until 10 years, and then plateaued. Morphologically, the frontal sinus developed posteriorly to cover the anterior part of the cranial cavity, extended ventrally in the anterior lateral part of the cranial cavity and the orbital region, and protruded into the zygomatic process of the frontal bone. The cranial cavity increased slowly from 0 years, with continued growth beyond 11 years at a reduced rate. The cranial cavity-to-skull ratio decreased because the skull volume significantly increased. Both the frontal sinus and cranial cavity volumes strongly correlated with skull volume, and a well-fitting regression line was obtained. This means that the volumes of the frontal sinus and cranial cavity correlate more closely with skull volume than with age. This is the first report on the non-destructive analysis of the changes in volume and morphology of the frontal sinus and cranial cavity in male brown bears.

Two cats were evaluated because of clinical signs consistent with tetraplegia or ataxia of four limbs and cerebellar signs. The cats were diagnosed with craniocervical junction abnormalities (CJAs) by radiographs, computed tomography and magnetic resonance imaging. Both cats underwent surgical stabilization using a patient-specific titanium atlantoaxial (AA) fixation plate and drill guide templates. In case 2, in addition to AA fixation, the separated dens and the occipital bone compressing the cerebellum were removed. Repositioning and fixation of the AA joint using a custom drill guide template and titanium plate system improved the gait of both cats, but the cerebellar signs persisted. Although CJAs are uncommon in cats, the present cases indicate that surgical stabilization with a custom fixation system may represent a feasible treatment option.

Sialocele recurrence in dogs following surgical excision of the monostomatic sublingual gland is often attributed to incomplete removal of sublingual gland tissue posterior to the site of duct rupture, suggested as solitary lobules of the monostomatic sublingual gland. Here we examined these solitary lobules in six healthy beagle cadavers. Gross anatomical observation revealed solitary lobules distributed along the major sublingual duct and separated from the rostral lobe of the monostomatic sublingual gland. Histologically, the solitary lobules were connected to the major sublingual duct and showed a mixed glandular structure similar to the monostomatic sublingual gland but distinct from the polystomatic sublingual gland. These findings elucidate the anatomical basis of sialocele recurrence and emphasize the importance of completely excising solitary lobules.