The myenteric plexus morphology, which varies depending on the morphology and motility of each intestinal segment, helps us to understand the intestinal physiology, however, it has not been reported in the rabbit small intestine. We, thus, investigated the myenteric plexus morphology in the rabbit small intestine using whole-mount preparations subjected to protein gene product 9.5 immunohistochemistry. The myenteric plexus was the most well-developed in the terminal part of the ileum, followed by the cranial duodenum and distal ileum. The other segments had significantly poorly developed myenteric plexuses than the terminal part of the ileum. Findings of this study may be useful to investigate the morphology of cells in the ganglia and their roles in the mechanisms underlying intestinal motor control.

In horses, the gut microbiota plays a critical role in maintaining intestinal homeostasis and overall health, but antimicrobial administration can disrupt its balance, resulting in dysbiosis, which can cause antibiotic-associated diarrhea. This study assessed the impact of intravenous cephalothin sodium administration on the equine gut microbiota by using microbial amplicon sequencing targeting the 16S-ITS-23S rRNA operon. Fecal samples from 39 clinically normal horses, 16 antibiotic-treated horses (cephalothin, n=5; minocycline, n=5; metronidazole, n=6, each administered for 5 days), and seven colitis-affected horses were collected. Cephalothin had minimal effects on microbial diversity, as α-diversity and β-diversity did not differ significantly from those in clinically normal horses (P>0.05). In contrast, minocycline and metronidazole significantly disrupted the microbial composition. Colitis-affected horses exhibited severe microbial alterations, including reduced species richness. Among the 52 microbial families significantly altered in colitis horses, none showed significant changes in response to cephalothin, suggesting its gut-microbiota-friendly characteristics. Notably, Verrucomicrobia subdivision 3, associated with mucosal integrity, remained stable in the cephalothin group, whereas its relative abundance significantly decreased in the minocycline, metronidazole, and colitis groups (P<0.05). These findings suggest that cephalothin poses a lower risk of equine microbiota disruption than other antimicrobials, making it a safer option in veterinary practice. Cephalothin could help to maintain gut microbial balance while ensuring effective infection control and reducing gastrointestinal complications. This study provides valuable evidence for optimizing antimicrobial selection, supporting equine gut microbiota health.

Bovine mycoplasma mastitis is highly transmittable and hard to treat by chemotherapy. It causes severe economic loss and is considered a major problem for milk production. Mycoplasma canadense is one of the causative agents of mycoplasma mastitis. A primer set to detect M. canadense was developed based on single nucleotide polymorphism-specific loop-mediated isothermal amplification. Using this primer set, 10 fg M. canadense DNA corresponding to the DNA amount of ~13 cells was detected within 40 min. Cross-reactivity with other bovine Mycoplasma spp., Acholeplasma laidlawii, and mastitis-related bacteria was not observed when ≤1 pg DNA was applied. These results would provide a basis for validating future experiments with spiked-milk and field samples for the development of rapid detection of M. canadense.

This study sought to create a simple method for screening and detecting oral bacteria associated with periodontal disease as well as to identify the bacterial species that had the strongest correlation with disease severity in dogs. Fifty-two dogs from the Kagoshima University Veterinary Teaching Hospital were included. The periodontal disease status, which included gingival recession, root surface exposure, and gingival redness, was determined through visual examination. Oral swab samples were taken from each dog’s gingival margin or tooth cervix using a sterile cotton swab following a standardized protocol. The collected samples were applied to our nanotechnology named sugar chain immobilized magnetized gold nanoparticle/magnetic microparticle (SGNP/MMP) method to obtain bacterial DNA, which was then subjected to qualitative and semiquantitative PCR analyses for 6 genera and 8 species of bacteria: Porphyromonas gingivalis (P. gingivalis), Tannerella forsythia (T. forsythia), Treponema denticola (T. denticola), Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Fusobacterium nucleatum (F. nucleatum), Prevotella intermedia (P. intermedia), Porphyromonas gulae (P. gulae), and Porphyromonas cangingivalis (P. cangingivalis). The severity of periodontal disease was most strongly correlated with T. denticola (associated with the gingival recession), followed by slight total bacteria and P. gingivalis+P. gulae, but no significant correlation was found with P. gulae. Within the scope of this study, the analytical method used may represent a useful standard for screening and detecting specific bacteria, and the quantity of T. denticola is linked to the severity of periodontal disease in dogs.

Felis catus papillomavirus (FcaPV) was first discovered in 2002. Seven genotypes (FcaPV-1/-2/-3/-4/-5/-6/-7) have been reported to date, at least one of which (FcaPV-2) is suggested to be implicated in squamous cell carcinoma (SCC); however, relevant epidemiological data on Japanese cats are limited. There is one report on relatively low FcaPV-2 prevalence in cats with SCC, largely in the Tokyo region. In this study, we investigated the prevalence of each FcaPV genotype in cats with SCC largely drawn from a peripheral region of Japan (Kyushu). Formalin-fixed paraffin-embedded (FFPE) specimens from 107 cats with SCC were subjected to DNA extraction for type-specific PCR assays, followed by confirmatory nucleotide sequencing. Overall, 16 cases (15.0%) were positive for FcaPV, and the results detected for FcaPV-1/-2/-3/-4/-5/-6/-7 were 0/107 (0.0%), 7/107 (6.5%), 4/107 (3.7%), 1/107 (0.9%), 3/107 (2.8%), 1/107 (0.9%), and 1/107 (0.9%), respectively. Our results suggest that FcaPV-2 is the prevalent papillomavirus type in cats with SCC across Japan, but the figure is lower than in other countries. This is also the first report on the detection of FcaPV-6 and FcaPV-7 in Japan, which previously have only been reported in Australia and New Zealand, respectively.

An 11-year-old castrated male Turkish Angora cat presented with chronic lethargy and inappetence was diagnosed with non-regenerative anemia, increased nucleated red blood cells, and thrombocytopenia. Tests for anemia-related infections were negative. Imaging revealed pleural effusion, hepatomegaly, splenomegaly, and enlarged abdominal lymph nodes, raising suspicion of a round cell tumor in the spleen. His anemia and pleural effusion did not improve despite chemotherapy with cytarabine administration. Erythroid precursor cells were identified in the pleural fluid. His condition deteriorated, progressing to dyspnea and necessitating euthanasia. Necropsy findings revealed extensive infiltration of CD71-positive neoplastic cells and a myeloid-to-erythroid precursor ratio of 0.02, indicating pleural metastasis. Pleural metastasis should be considered a differential diagnosis in feline acute erythroid leukemia cases presenting with pleural effusion.

Lactate levels are critical indicators of severe, life-threatening conditions and are widely used as prognostic markers in veterinary emergency care. Blood gas analyzers and portable lactate meters are common tools, but discrepancies between devices, especially at high lactate levels, have been reported. This study aimed to evaluate inter-device variability in canine lactate measurement. Lactate levels in 118 dogs were measured using a blood gas analyzer and a portable lactate meter. A strong correlation (R=0.906) was observed; however, the portable meter exhibited an 18% positive bias primarily characterized by additive error. These findings emphasize the need for careful device selection and the standardization of lactate measurement methods.

Endotracheal intubation plays a crucial role in airway management in mice. Transoral endotracheal intubation (TEI) offers a less invasive alternative to tracheostomy and is more ideal for chronic experiments. Despite the development of various TEI techniques in mice, the lack of accessible and well-established methods that do not require specialized equipment hinders routine research. We developed a feasible and highly successful method for TEI in C57BL/6JJcl mice using a combination of commercially available research equipment. A success rate of 97.5% was achieved within 21.2 ± 8.9 sec (mean [standard deviation]) with no observed complications in the 40 mice studied. This method simplifies TEI without specialized tools and provides practical guidance for consistent application in routine research settings.

A six years and four months old Japanese Black cow presented with a solid mass in the left and middle mandible. Treatment involved the administration of antibiotics and the mass was surgically removed. Recurrence of the mass was observed, and the cow exhibited hypersalivation and anorexia before dying naturally. A necropsy revealed a solid subcutaneous mass infiltrating the oral cavity and the left mandibular bone, with hemorrhage and necrosis. Histopathological examination revealed clear, plasmocytic, spindle-shaped, or polygonal neoplastic cells. The neoplastic cells were immunoreactive with cytokeratin, cytokeratin 5, vimentin, smooth muscle actin, and p63. Considering these findings, the mass was diagnosed as malignant myoepithelioma. This is the first report of malignant myoepithelioma arising from the salivary glands in a cow.

Although gastrointestinal stromal tumors (GISTs) are rare in guinea pigs, few cases have been reported recently. Here, we present a case of a GIST in a guinea pig that showed atypical cellular morphology with extensive epithelioid-like cells. The tumor was located between the small intestine and the tip of the cecum and originated from the jejunum. Histopathologically, the tumor cells were mixed with epithelioid-like or short spindle-shaped cells with round-to-oval nuclei. Multinucleated cells were also observed. The tumor metastasized to the peritoneal lymph node. Immunohistochemically, the tumor cells were diffusely positive for vimentin and c-kit. A mutation (large deletion) in exon 11 of the KIT gene was detected using PCR-direct sequencing. Including the previous five cases, GISTs in guinea pigs tended to exhibit nuclear atypia rather than the typical morphology observed in canine GISTs, despite being diagnosed as spindle-shaped. Additionally, the present case exhibited more nuclear atypia, which may be a characteristic feature of GISTs in guinea pigs.

A 10-year-old, male neutered pug dog with a history of gallstones was found to have a mass near the caudate lobe of the liver upon ultrasound examination. The mass was red to dark red, multinodular, measuring 3 × 3 × 4 cm and not continuous to the liver. Histopathological examination revealed sheet-like proliferation of polygonal neoplastic cells resembling hepatocytes with mild atypia, and no portal areas were observed. The tumor cells were positive for HepPar-1 and negative for cytokeratin 7. The macrophages decreased in neoplastic lesion compared to normal area. Based on these findings, this case was diagnosed as a hepatocellular carcinoma of ectopic liver origin. This is the second reported case showing the potential for ectopic liver to develop into tumors in dogs.

A young female Golden Retriever with a portosystemic shunt presented with hypoalbuminemia, hyperammonemia, and severe ascites, ultimately succumbing to the illness. Necropsy revealed renal papillary necrosis in the right renal pelvis. Histological examination identified an encapsulated structure within the renal pelvis containing basophilic granules surrounded by an eosinophilic, multilayered capsule. Mass spectrometry analysis of the encapsulated structure identified predominant Staphylococcus pseudintermedius-specific proteins. This finding was further confirmed by PCR and immunohistochemistry, establishing an infection caused by Staphylococcus spp. This is the first documented case of papillary necrosis with an encapsulated structure as a severe manifestation of pyelonephritis associated with S. pseudintermedius.

Human pharmaceuticals are widely used in veterinary medicine. Nevertheless, identifying the optimal pharmaceuticals and dosages has been a significant challenge, as these medications may not be efficacious or may even be toxic to small animals. Following the approval of a pharmaceutical for human use, comprehensive non-clinical information is made public in Japan as Summary Technical Documentation (STED) and in the U.S. as Drug Approval Packages. As canines are often employed in non-clinical investigations, the information could prove invaluable in identifying the optimal pharmaceuticals and dosages. Sodium-glucose co-transporter 2 (SGLT2) inhibitors represent a class of anti-diabetic agents for humans, with a total of nine drugs currently approved in Japan, the U.S. and the E.U. Among them, dapagliflozin and empagliflozin have been approved for the treatment of chronic heart failure. In canines, myxomatous mitral valve disease (MMVD) represents the most prevalent etiology of chronic heart failure. Despite the recommendation of pimobendan and loop diuretics as standard-of-care medications, MMVD remains a disease with a poor prognosis due to its progressive nature. We examined the pharmacology, safety, and pharmacokinetics of the globally approved SGLT2 inhibitors (empagliflozin, canagliflozin, and dapagliflozin) in canines in the STED. Based on these results, we propose dapagliflozin as the most favorable pharmaceutical in canines. We also discuss the potential effects of SGLT2 inhibitors on canine MMVD, considering the similarities between canine MMVD and human chronic heart failure.

Postpartum depression is a prevalent mental disorder that affects mothers and has adverse effects on families. The decline in parenting quality associated with postpartum depression raises concerns about the adverse impact on children. Therefore, it is desirable to prevent deterioration in parenting quality in depressed mothers. This study aims to investigate whether antidepressive agents can prevent the decline in parenting quality associated with postpartum depression. Maternal care and sucrose palatability were evaluated in postpartum female mice with intraperitoneal lipopolysaccharide (LPS) administration 24 hr before testing. In the maternal care test, LPS increased the latency to retrieving pups into the nest and to crouching over the pups in the nest and decreased the duration for crouching over the pups. Furthermore, in the sucrose preference test, the ratio of sucrose intake decreased. Next, dopamine D2 receptor agonists (quinpirole and bromocriptine), a selective serotonin reuptake inhibitor (fluoxetine), or a tricyclic antidepressant (imipramine) was intraperitoneally administered 30 min before LPS administration. Treatment with quinpirole and bromocriptine, but not fluoxetine and imipramine, decreased the crouching latency and increased the crouching duration in LPS-treated postpartum females. On the other hand, all of the antidepressive agents did not affect the ratio of sucrose intake. Furthermore, the dopamine D2 receptor antagonist haloperidol disturbed the effects of quinpirole and bromocriptine on maternal care. These results indicate that dopamine D2 receptor agonists can prevent the decline in parenting quality via dopamine D2 receptor in LPS-induced postpartum depression model mice.

We aimed to investigate the effects of desflurane (Des), sevoflurane (Sevo), and remifentanil (Remi) on the modulation of hemodynamic responses under 10-Hz electrical stimulation of the mental nerve in rabbits, which yields both hypertensive and hypotensive responses. Male Japan White rabbits (n=10, weight approximately 2.5 kg) were used. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) of the animals before and after electrical stimulation of the mental nerve was observed at baseline and after administration of Sevo or Des and Remi. The magnitude of the blood pressure (BP) decrease and increase following electrical stimulation were observed. The BP hypotensive response was suppressed by Remi at 0.8 μg/kg/min; contrastingly, it was potentiated by Des and Sevo. The potentiating effect of Des or Sevo on the hypotensive response was counteracted by remifentanil. The suppression of the hypertensive response by Sevo 0.4 MAC was attenuated by the concomitant use of Remi 0.4 μg/kg/min. The hypertensive response was suppressed by Des, Sevo, and Remi. The combination of Des or Sevo with Remi suppressed hypertensive response. These results suggest that combined administration of Des or Sevo with Remi suppressed both hypotensive and hypertensive responses to electrical stimulation of the mental nerve in a well-balanced manner and stabilized the hemodynamics in rabbits.

House-soiling is the most common problem faced by cat owners and is the main reason for owners surrendering cats to animal shelters. Although many studies have reported on inappropriate cat excretion in relation to the toilet environment, few reports have explored the preferences of cats kept indoors when multiple litter boxes are presented. In this study, we investigated the effect of litter box size and litter types on the excretion behavior of cats and whether a litter environment that combines their preferred elements would change their excretion behavior. Our findings indicated that cats preferred litter boxes measuring ≥50 cm as well as clumping clay litter. Moreover, a comfortable litter environment combining these two elements promoted normal urination behavior while improving house-soiling (both urination and defecation) as well as three dissatisfied behaviors during excretion. The results of the present may be beneficial for cat owners and cats exhibiting house-soiling, and they could facilitate the reduction of the number of cats being abandoned owing to house-soiling.

The high oxygen conditions (80% oxygen and 20% carbon dioxide) of oxygen-modified atmosphere packaging (high O₂ MAP) maintain the quality of meat. This study investigates the cultivability and viability of Campylobacter jejuni in a high O₂ MAP environment, with different strains investigated to examine whether cultivability is affected by aerotolerance. C. jejuni strains spiked chicken meat was exposed to high O₂ MAP and assessed using culture and viability-digital PCR. The results indicated suppression of the cultivability of C. jejuni under high O₂ MAP conditions, with evidence suggesting that this may not be due to aerotolerance. However, the viability of C. jejuni was not affected, indicating that bacterial cells might have been induced to a viable but non-culturable state.

In veterinary surgery, the choice of suture is determined by the surgeon based on a combination of factors, such as differences in disassembly time, price, and suture site. However, no unified comparison has been made across companies, and the differences are often unclear. In this study, we compared the mechanical properties (maximum tensile load, maximum extension, and maximum twist) of seven synthetic absorbable sutures at baseline (day 0) and over time under different pH conditions (PBS: pH 7.2, acidic: pH 5.6, alkaline: pH 8.8). At baseline, the comparison showed no significant difference in tensile load, but monofilament sutures exhibited a significantly higher extension than multifilament sutures. In terms of twist, the results varied, with significantly higher values for PDS II and MonoSynthe, both of which are polydioxanone based, suggesting that material differences may have influenced the results. On the other hand, multifilament sutures showed lower values over time in all conditions compared to monofilament sutures. Therefore, it was concluded that multifilaments were more strongly affected by solution immersion than monofilaments and lost their mechanical properties earlier. The results also revealed distinct patterns in twist behavior over time, especially MonoSynthe exhibited much lower twist values under alkaline pH compared to other monofilament sutures. These results suggest that twist could be a valuable addition to conventional evaluation methods for suture characteristics. Further multifaceted evaluations will contribute to the development of more comprehensive selection criteria for sutures used in veterinary clinical practice.

A 5-year-old, 7.6-kg male miniature dachshund presented with right-sided congestive heart failure and ascites. Echocardiography revealed a tricuspid valve tumor. Open-heart surgery with cardiopulmonary bypass was performed via right atriotomy and the tumor was excised from the septal leaflet of the tricuspid valve. Histopathological findings confirmed the diagnosis of a myxoma. Postoperatively, the ascites resolved and no signs of right-sided congestive heart failure were observed. The dog remained clinically stable for 727 days after surgery. This conclusion reinforces the novelty of this report, as successful resection of a tricuspid valve myxoma has not been reported in the veterinary literature.

Heat exposure at the physiological level of oocyte-cumulus-granulosa cell complexes (OCGCs) during in vitro growth (IVG) culture decreases the reduced glutathione (GSH) level of oocytes, an antioxidant, but its mechanism has been unclear. We subjected OCGCs to IVG for 4, 8, or 12 days and investigated the effects of heat exposure on the gene expression of cumulus-granulosa cells associated with antioxidant capacity. Heat exposure did not alter the expression of genes related to GSH synthesis or reuse. Conversely, heat exposure increased mRNA expression of superoxide dismutase 2 and decreased that of glutathione peroxidase 1, which are antioxidant enzymes. Ultimately, heat exposure alters the gene expression of antioxidant enzymes in growing follicles, which may indirectly decrease the GSH level of oocytes.

This study investigated the seroprevalence of bovine leukemia virus (BLV) in beef breeding cattle in Ibaraki, revealing a seroprevalence of 43.0% with a bimodal distribution in farms classified as either BLV-negative or very-highly infected. These results underscore the need to implement appropriate strategies for very-highly infected farms. In particular, determining the culling prioritization of cattle is absolutely necessary. It was revealed that effective control in very-highly infected farms is difficult based on types of operation or herd size. On the other hand, high-transmission-risk cattle were widely distributed across entire Ibaraki and were significantly more prevalent in very-highly infected farms. These findings suggest that the transmission risk classification is a potentially effective strategy for culling prioritization under the current circumstances in Ibaraki.