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Three-dimensional (3D) organoid culture holds great promises in cancer precision medicine. However, Matrigel and stem cell-stimulating supplements are necessary for culturing 3D organoid cells. It costs a lot of money and consumes more time and effort compared with 2D cultured cells. Therefore, the establishment of cheaper and Matrigel-free organoid culture that can maintain the characteristics of a part of 3D organoids is demanded. In the previous study, we established a dog bladder cancer (BC) 3D organoid culture system by using their urine samples. Here, we successfully isolated cells named “2.5D organoid” from multiple strains of dog BC 3D organoids using 2.5 organoid media. The cell proliferation speed of 2.5D organoids was faster than parental 3D organoid cells. The expression pattern of stem cell markers was close to 3D organoids. Injection of 2.5D organoid cells into immunodeficient mice formed tumors and showed the histopathological characteristics of urothelial carcinoma similar to the injection of dog BC 3D organoids. The 2.5D organoids had a similar sensitivity profile for anti-cancer drug treatment to their parental 3D organoids. These data suggest that our established 2.5D organoid culture method might become a reasonable and useful tool instead of 3D organoids in dog BC research and therapy.

Dogs have been considered as an excellent immunocompetent model for human melanoma due to the same tumor location and the common clinical and pathological features with human melanoma. However, the differences in the melanoma transcriptome between the two species have not been yet fully determined. Considering the role of oncogenes in melanoma development, in this study, we first characterized the transcriptome in canine oral melanoma and then compared the transcriptome with that of human melanoma. The global transcriptome from 8 canine oral melanoma samples and 3 healthy oral tissues were compared by RNA‑Seq followed by RT‑qPCR validation. The results revealed 2,555 annotated differentially expressed genes, as well as 364 novel differentially expressed genes. Dog chromosomes 1 and 9 were enriched with downregulated and upregulated genes, respectively. Along with 10 significant transcription site binding motifs; the NF‑κB and ATF1 binding motifs were the most significant and 4 significant unknown motifs were indentified among the upregulated differentially expressed genes. Moreover, it was found that canine oral melanoma shared >80% significant oncogenes (upregulated genes) with human melanoma, and JAK‑STAT was the most common significant pathway between the species. The results identified a 429 gene signature in melanoma, which was up‑regulated in both species; these genes may be good candidates for therapeutic development. Furthermore, this study demonstrates that as regards oncogene expression, human melanoma contains an oncogene group that bears similarities with dog oral melanoma, which supports the use of dogs as a model for the development of novel therapeutics and experimental trials before human application.

In human and dogs, bladder cancer (BC) is the most common neoplasm affecting the urinary tract. Dog BC resembles human muscle‐invasive BC in histopathological characteristics and gene expression profiles, and could be an important research model for this disease. Cancer patient‐derived organoid culture can recapitulate organ structures and maintains the gene expression profiles of original tumor tissues. In a previous study, we generated dog prostate cancer organoids using urine samples, however dog BC organoids had never been produced. Therefore we aimed to generate dog BC organoids using urine samples and check their histopathological characteristics, drug sensitivity, and gene expression profiles. Organoids from individual BC dogs were successfully generated, expressed urothelial cell markers (CK7, CK20, and UPK3A) and exhibited tumorigenesis in vivo. In a cell viability assay, the response to combined treatment with a range of anticancer drugs (cisplatin, vinblastine, gemcitabine or piroxicam) was markedly different in each BC organoid. In RNA‐sequencing analysis, expression levels of basal cell markers (CK5 and DSG3) and several novel genes (MMP28,CTSE,CNN3,TFPI2,COL17A1, and AGPAT4) were upregulated in BC organoids compared with normal bladder tissues or two‐dimensional (2D) BC cell lines. These established dog BC organoids might be a useful tool, not only to determine suitable chemotherapy for BC diseased dogs but also to identify novel biomarkers in human muscle‐invasive BC. In the present study, for the 1st time, dog BC organoids were generated and several specifically upregulated organoid genes were identified. Our data suggest that dog BC organoids might become a new tool to provide fresh insights into both dog BC therapy and diagnostic biomarkers.

The changes in intra-atrial blood coagulability of acute phase after development of atrial fibrillation (AF) have not been elucidated in human. In the present study, blood coagulability were examined in the intra-atrial and peripheral regions during the acute phase after development of rapid atrial pacing (RAP) in experimentally created model dog similar to AF, using Total Thrombus-formation Analysis System (T-TAS) that is capable of comprehensively evaluating thrombogenicity in the bloodstream in the microvascular channel. According to the results, both the coagulating function-evaluating time to +10 kPa (T10) and occlusion time (OT) of the AR chip (chip for thrombus analysis mixed with coagulation and platelet) were significantly shortened in the atrial blood as early as 30 min after pacing (T10, 150.5 ± 40.5 s; OT, 212.4 ± 44.3 s) compared to the pre-pacing levels (T10, 194.5 ± 47.5 s; OT, 259.9 ± 49.5 s) (P

Dog bladder cancer (BC) is mostly muscle-invasive (MI) with poor prognosis, and its pathogenesis is close to human MIBC. Three-dimensional (3D) organoid culture ensures novel knowledge on cancer diseases including BC. Recently, we have established dog BC organoids (BCO) using their urine samples. BCO recapitulated the epithelial structures, characteristics, and drug sensitivity of BC-diseased dogs. However, organoids from dog normal bladder epithelium are not established yet. Therefore, the present study aimed to establish dog normal bladder organoids (NBO) for further understanding the pathogenesis of dog BC and human MIBC. The established NBO underwent various analyzes including cell marker expressions, histopathological structures, cancer-related gene expression patterns, and drug sensitivity. NBO could be produced non-invasively with a continuous culturing and recapitulated the structures and characteristics of the dog's normal bladder mucosal tissues. Different drug sensitivities were observed in each NBO. The analysis of RNA sequencing revealed that several novel genes were changed in NBO compared with BCO. NBO showed a higher expression of p53 and E-cadherin, but a lower expression of MDM2 and Twist1 compared with BCO. These results suggest that NBO could be a promising experimental 3D model for studying the developmental mechanisms of dog BC and human MIBC.

Bladder cancer (BC), a main neoplasm of urinary tract, is usually inoperable and unresponsive to chemotherapy, indicating a necessity for more effective therapies. As a novel experimental model for muscle-invasive BC, we previously established a culture method of dog BC organoids. In the present study, the detailed in vitro and in vivo anti‐tumor effects of trametinib were investigated by using this model. In each BC organoid strain, epidermal growth factor receptor (EGFR)/ERK signaling was upregulated compared with normal bladder cells. Trametinib even at a low concentration inhibited the cell viability of BC organoids and the activation of ERK through decreasing expression of c-Myc, ELK1, SIK1, and PLA2G4A. Trametinib arrested cell cycle of BC with few apoptoses. Additionally, trametinib decreased expression of CD44, while YAP1 was unexpectedly upregulated. Dual treatment of BC organoids with trametinib and YAP inhibitor, verteporfin extremely inhibited the cell viability with apoptosis induction. Moreover, trametinib induced basal to luminal transformation of BC organoids by upregulating luminal markers (ERBB2 and GATA3) and downregulating basal ones (CK5 and DSG3). In vivo, trametinib decreased the tumor growth of BC organoids in mice and the xenograft-derived organoids from trametinib-administered mice showed enhanced sensitivity to carboplatin due to MSH2 upregulation. Our data suggested a new strategy of trametinib-YAP inhibitor or trametinib-carboplatin combination as a promising treatment of BC. Dog BC organoid model may hopefully become a promising research tool for human muscle-invasive BC in near future.

In dogs, pancreatic acinar cell injury is thought to be caused by decreased pancreatic blood flow due to heart failure. In previous our report, it demonstrated that decreased heart function causes a significant decrease in pancreatic blood flow in heart failure dog model caused by rapid ventricular pacing (RVP). However, the types of histopathological changes remain unclear. We aimed to verify the types of histopathological changes occurring in the pancreatic tissue due to decreased heart function. After RVP for 4 weeks, atrophy of pancreatic acinar cells, characterized by a decrease in zymogen granules, was observed in all areas of the pancreas. In conclusion, the result of this study suggests that attention should be paid to ischemia/hypoperfusion injury in the pancreas.

OBJECTIVE To examine whether glucocorticoid (GC) administration alters hippocampal cerebral blood flow (CBF) or volume in dogs. ANIMALS 6 clinically normal adult Beagles. PROCEDURES Each dog underwent CT and MRI to measure the CBF in the hippocampus, basal ganglia, thalamus, and cerebral cortex and the volume of the hippocampus in each hemisphere of the brain before (day 0) and during (days 7 and 21) a 21-day treatment with prednisolone (1.0 mg/kg, PO, q 24 h) and famotidine (0.5 mg/kg, PO, q 12 h). Results for hippocampal volume, anesthesia-related variables, and semiquantitative measurements of CBF (hemisphere-specific ratios of the CBF in the hippocampus, basal ganglia, and thalamus relative to the CBF in the ipsilateral cerebral cortex and the left cerebral cortex CBF-to-right cerebral cortex CBF ratio) were compared across assessment time points (days 0, 7, and 21). RESULTS The ratios of CBF in the right hippocampus and right thalamus to that in the right cerebral cortex on day 21 were significantly lower than those on day 0. No meaningful differences were detected in results for the hippocampal volume in either hemisphere or for the anesthesia-related variables across the 3 time points. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that GC administration reduced CBF in the hippocampus and thalamus in dogs of the present study, similar to that which occurs in humans. Research on GC-related brain alteration in dogs could potentially contribute to advancements in understanding Alzheimer disease in humans and neurodegenerative conditions in dogs.

To date, coagulation tests are unable to reflect in vivo coagulation status in the same system, including platelet function, fibrin clot formation, and whole blood flow. The Total Thrombus Analysis System (T-TAS), which is a microfluidic assay that simulates conditions in vivo, measures whole blood flow at defined shear rates under conditions designed to assess platelet function (PL-chip) or coagulation and fibrin clot formation (AR-chip). The T-TAS records occlusion start time, occlusion time, and area under the curve. We evaluated this test in healthy control dogs. We also investigated the effect in vivo of acetylsalicylic acid (ASA), and the effect in vitro of an anticoagulation drug (dalteparin; low-molecular-weight heparin; LMWH). The CV of the AUC of both chips was good (CVs of 6.45% [PL] and 1.57% [AR]). The inhibition of platelet function by ASA was evident in the right-shift in the PL test pressure curve. The right-shift in the AR test pressure curves showed that the administration of LMWH inhibited both platelets and the coagulation cascade. The T-TAS may be useful in the evaluation of canine blood coagulation.

The pancreas is believed to be vulnerable to hypoperfusion. In dogs with acute pancreatitis, pancreatic ischemia due to heart failure can worsen the condition. However, changes in pancreatic blood flow associated with decreased cardiac function have not been previously studied in dogs. Therefore, we aimed to identify and compare changes in pancreatic versus renal blood flow as a result of cardiac dysfunction. Seven dogs were subjected to rapid ventricular pacing to create heart failure models. Noninvasive blood pressure measurement, ultrasonic cardiography, contrast-enhanced ultrasonography for pancreatic blood flow measurement, and para-aminohippuric acid clearance for renal blood flow measurement were performed before starting and at 2 and 4 weeks after starting the pacing. Left ventricular cardiac output and mean blood pressure decreased at 2 and 4 weeks after starting the pacing, and pancreatic blood flow decreased at 2 and 4 weeks after starting the pacing. However, renal blood flow did not change at 2 weeks but decreased 4 weeks after starting the pacing. Overall, this study demonstrated that reduced pancreatic blood flow due to cardiac dysfunction occurs, similar to renal blood flow. This suggests that decreased pancreatic blood flow is not unusual and may frequently occur in dogs with heart failure. The results of this study support the speculation that heart failure can exacerbate acute pancreatitis. Additionally, this study provides useful basic information for designing further studies to study this association.

Introduction Changes in blood characteristics in the atrium and peripheral vessels in patients with non-valvular atrial fibrillation (NVAF) are unclear. We investigated chronological changes in blood characteristics in the atrium and peripheral vessels in a dog model of NVAF by using a total thrombus-formation analysis system (T-TAS). Materials and methods In NVAF model dogs (n = 8, 390 bpm rapid atrial pacing), atrial and peripheral blood samples were collected. Using this blood, T-TAS was performed before and 1, 2, and 3 weeks after the onset of rapid atrial pacing. Results Occlusion time (OT: time to +80 and +60 kPa in the AR and PL chips, respectively) and area under the flow pressure curve (AUC) were measured using the AR chip (for mixed white thrombus analysis) and PL chip (for platelet thrombus analysis). OT of the AR chip showed shortening as early as 1 week after NVAF onset, which continued for 3 weeks. OT of the PL chip showed significant shortening in atrium blood only 3 weeks after NVAF onset. By contrast, peripheral blood showed no significant changes in OT or AUC with both AR and PL chips. Conclusions In our dog model of NVAF, thrombus formation accelerated in the atrium as early as 1 week after NVAF onset and continued for 3 weeks, but no significant changes were found in peripheral blood. We conclude that antithrombotic therapy should be started early after NVAF onset even if no changes in coagulation activity are observed in peripheral blood.

Simple Summary In cases of cancer metastasis, some tumor cells circulate in blood (CTCs) and function as a seed for metastasis. These cells are important for detailed study of the molecular basis of metastasis. However, their few numbers and difficult isolation hinder its analysis. Apheresis, a process used to isolate a specific component of blood, can efficiently separate peripheral blood monocyte (PBMC), whose density is closely like that of CTCs. In the present study we used the dogs as a precious model of human’s cancers to check the safety and feasibility of apheresis and to separate PBMC and infused MCF7 cells using Spectra Optia apheresis machine (Terumo). The process was performed safely to capture PBMC and MCF7. The captured MCF7 cells were regrown up in vitro and characterized. In conclusion, Spectra Optia apheresis machine (Terumo) can be used safely to isolate CTCs from dogs blood with precautions to keep hemodynamic stability. Abstract In patients with solid tumors, circulating tumor cells (CTCs) spread in their blood and function as a seed for metastases. However, the study of CTCs has been limited by their rarity, low frequency, and heterogeneity. The efficient collection of CTCs will contribute to further research of metastatic cancers. Apheresis is a process in which the whole blood of an individual is passed through a machine that isolates a particular constituent and returns the remainder to the circulation. In the present study, we investigated the safety and feasibility of apheresis to separate peripheral blood monocytes (PBMCs), whose density is closely similar to that of CTCs, and to capture intravenously administered human breast cancer cells, MCF7s, from the dogs. No life-threatening events were observed in dogs during the apheresis process. The changes in the hemogram were transient and recovered gradually within a few days after apheresis. During apheresis, 50 mL of PBMCs could be collected from each dog. Notably, a thrombus was formed along the circuit wall during apheresis, which decreased the blood collection pressure. MCF7 cells were successfully captured by the apheresis machine. The captured cells were regrown in vitro and characterized compared with the original cells. In conclusion, apheresis could be safely performed in dogs to isolate CTCs with precautions to maintain hemodynamic stability.

MicroRNAs (miRNAs) dysregulation contribute the cancer pathogenesis. However, the miRNA profile of canine oral melanoma (COM), one of the frequent malignant melanoma in dogs is still unrevealed. The aim of this study is to reveal the miRNA profile in canine oral melanoma. MiRNAs profile of oral tissues from normal healthy dogs and COM patients were compared by next-generation sequencing. Along with tumour suppressor miRNAs, we report 30 oncogenic miRNAs in COM. The expressions of miRNAs were further confirmed by quantitative real-time PCR (qPCR). Pathway analysis showed that deregulated miRNAs impact on cancer and signalling pathways. Three oncogenic miRNAs targets (miR-450b, 301a, and 223) from human study also were down-regulated in COM and had a significant negative correlation with their respective miRNA. Furthermore, we found that miR-450b expression is higher in metastatic cells and regulated MMP9 expression through a PAX9-BMP4-MMP9 axis. In silico analysis indicated that miR-126, miR-20b, and miR-106a regulated the highest numbers of differentially expressed transcription factors with respect to human melanoma. Chromosomal enrichment analysis revealed the X chromosome was enriched with oncogenic miRNAs. We comprehensively analyzed the miRNA&rsquo, s profile in COM which will be a useful resource for developing therapeutic interventions in both species.

Among small non-coding RNAs (sncRNAs/sRNAs), the functional regulation of microRNAs (miRNAs) has been studied in canine oral melanoma (COM). However, the expression level of other sncRNAs, like small nucleolar RNAs (snoRNAs), small nuclear RNAs (snRNAs), transfer RNA-derived fragments (tRFs) and PIWI-interacting RNAs (piRNAs), in COM is unknown. The aim of this study was to investigate sncRNAs other than miRNAs in COM from our small RNA sequencing project (PRJNA516252). We found that several snRNAs and piRNAs were upregulated, whereas tRFs and snoRNAs were downregulated in COM. Upregulation of U1 snRNA and piR-972, and downregulation of tRNA-ser (1) and snoRA24 was confirmed in dog melanoma tissue and cell lines by quantitative reverse transcription PCR. Consistently, the expression of tRNA-ser (1) and snoRA24 in plasma of COM cases was also decreased. Finally, we found a similar expression trend of U1 and snoRA24 in the human cutaneous melanoma cell line, MEWO, compared with human epidermal melanocyte cells (HEMa-Lp). In our study, snRNA, snoRNA, tRFs and piRNA were dysregulated during melanoma progression. Moreover, the melanoma-associated expression of U1 and snoRA24 was similar in human and dog melanoma.

A 15-year-old neutered male Persian cat was presented with recurrent hematemesis and melena. Abdominal ultrasonography and computed tomography revealed a mass in the proximal descending duodenal wall. Endoscopic examination revealed hemorrhage on the luminal side of the mass. Fine-needle aspiration of the mass was performed. Microscopic analysis revealed a cluster of cells with oval nuclei and indistinct cell borders, suggesting a neoplastic disease of neuroendocrine origin. The mass located near the major duodenal papilla was partially resected, and the bleeding was stopped by cauterization. However, the surgical procedures could not control the hemorrhage from the tumor mass, and the cat died of severe anemia. Immunohistopathological analysis revealed that the tumor was a duodenal carcinoid.

A 6-year-old neutered male Yorkshire Terrier presented with recurrent pericardial effusion. Although clinical examinations including computed tomography were inconclusive, an exploratory thoracotomy revealed multiple small nodules and plaques on the inner surface of the pericardial sac (Day 1). A subtotal pericardiectomy was performed to prevent cardiac tamponade due to the increasing pericardial effusion, and the resected section of the pericardium was histopathologically diagnosed with mesothelioma. After surgery, chemotherapy with intrathoracic carboplatin was commenced. During the course of the treatment, a detailed follow-up ultrasonographic scan was performed to detect early lesions disseminated on the pleura, originating from the primary pericardial mesothelioma. On Day 101, the minute pleural nodules, which were disseminated lesions as predicted, were successfully imaged by ultrasonography. As the clinical stage advanced, the nodules were observed to gradually increase in size and number, implying tumor progression. These observations highlight the feasibility of ultrasonography in detecting minute disseminated lesions at an early stage, monitoring tumor progression, and thereby, predicting the prognosis of canine pericardial mesothelioma.

Maintaining a good ventricular systolic function is important in the long-term therapy of dogs with supraventricular tachyarrhythmia (SVTA). The objective of this study was to evaluate the inhibitory effect of telmisartan on myocardial injury and the resulting ventricular systolic dysfunction in a canine model of SVTA. A total of 14 dogs were randomly assigned to a Telmisartan (oral telmisartan, 1.0 mg/kg daily, n=7) or a Control (no drug administration, n=7) group; the duration of rapid atrial pacing (RAP) was 3 weeks for both groups. The cardiac troponin I (cTnI) concentration in the Control group was significantly increased after 3 weeks compared to that before RAP initiation (baseline), but no significant difference was observed in the Telmisartan group. Moreover, the cTnI concentration at 3 weeks was significantly lower in the Telmisartan group than in the Control group. The left ventricular fractional shortening was significantly decreased at 3 weeks compared to that at baseline in both groups. However, fractional shortening at 3 weeks was significantly higher in the Telmisartan group than in the Control group. The cardiac output values in the Control group were significantly decreased at 3 weeks compared with those at baseline, but no significant difference was observed in the Telmisartan group. This study demonstrates that telmisartan inhibits the reduction in ventricular systolic function and prevents myocardial injury in a canine model of SVTA. Therefore, telmisartan is suggested as a novel treatment for canine SVTA.

Examination of our necropsy records for the period 2005 to 2014 yielded 41 cases of the endomyocardial form of restrictive cardiomyopathy among 327 cats with evidence of heart disease, and here, we reviewed their epidemiological and clinical features. The medical data obtained retrospectively included signalment, presenting complaints, findings of physical examination, results of various diagnostic tests, methods of treatment and survival times. Except for one Chinchilla Persian cat, all were domestic short-haired cats. The mean age at death was 7.3 ± 4.5 years (median, 6 years; range, 4 months to 19 years), and males accounted for 61% (25/41) of the total. Dyspnea was the most common clinical sign, being evident in 83% (35/41) of the cats. Hind limb paresis or paralysis due to aortic thromboembolism was evident in 41% (17/41). Arrhythmias of atrial origin were common. Echocardiography commonly revealed left atrial or biatrial enlargement with severe endocardial thickening of the left ventricle. Most of the affected cats had a poor outcome; the disease duration ranged from 1 to 977 days, and the median survival period was 30 days.

A 14-year-old intact male West Highland White Terrier weighing 6.9 kg was admitted to the Tokyo University of Agriculture and Technology Animal Medical Center with the complaint of syncope after showing signs of nausea during feeding. Sinus arrest induced by deglutition was confirmed using a Holter electrocardiography test. However, the clinical symptoms significantly improved after implantation of a permanent pacemaker. Seven months after implantation, the dog died from acute pancreatitis, a cause unrelated to the syncope. Immediately after its death, the heart, lungs, gastrointestinal tract, and other organs were dissected and examined histopathologically. The brain was also examined using magnetic resonance imaging. Examination results led to the diagnosis of swallowing-induced situational syncope.

Quantitative analysis of left ventricular (LV) deformation based on two-dimensional speckle tracking echocardiography (2D STE) has increasingly been used to assess segmental and global function because conventional echocardiography is influenced by tethering effects of adjacent myocardium and cardiac translational motion. Hypothesis: (1) 2D STE can be useful to detect subtle regional changes in the LV contractility during development of tachycardia-induced cardiomyopathy (TIC) to heart failure in awake dog; (2) oxidized glutathione (GSSG) and reduced glutathione (GSH) levels are associated with the development of its respective segmental wall motion abnormalities (WMA). 6 healthy canine female Beagles were examined using 2D STE myocardial strain analysis before and for 8 weeks on week basis of rapid ventricular pacing (RVP) and at the end of study each myocardial segment were evaluated for oxidative status (GSH:GSSG ratio). 2D STE showed an initial peak of reduced global radial strain at 2 weeks of RVP in all three cardiac levels analyzed in which the affected segments showed a decreased transmural fiber shortening from anteroseptal to inferior segments distributed in helical pattern suggesting impaired contractility from part of left band to apical loop of spiral muscle band while global circumferential strain showed to be reduced since the fifth week of RVP particularly in the base and midventricular levels of ascending segment in clockwise direction from lateral to inferior segments. The most affected segments are localized in the lateral to posterior wall, however, segmental oxidative stress analysis did not show correlation with WMA detected by strain. 2D STE strain demonstrated to be a reliable tool for evaluation of LV myocardial deformation in TIC canine model showing an earlier significant WMA using radial strain and later using circumferential strain which may be of importance for improvement of diagnosis and therapy in naturally occurring canine cardiomyopathy and for earlier detection of WMA after suboptimal pacemaker lead placement.

This study was designed to assess the progression of pulmonary arterial hypertension (PAH) and the effectiveness of therapy using recently investigated echocardiographic parameters. PAH is characterized by the progressive elevation of pulmonary artery pressure and right ventricular hypertrophy and dysfunction, which ultimately results in right-sided heart failure and death. Echocardiography results and invasive measurements of right and left ventricular systolic pressures were compared after 3-week administrations of sildenafil (S group), pimobendan (P group), nicorandil (N group), and their combinations (SP and SPN groups) in male rats with monocrotaline (MCT)-induced pulmonary hypertension (M group) and without this condition (C group). The groups that received pimobendan alone and in combinations (SP and SPN groups) showed improvement in their echocardiographic parameters of systolic function. A significant improvement of diastolic function was achieved in the SPN group. Invasive measurements showed the most significant decreases of right ventricular systolic pressure in the N and SPN groups, and the use of pimobendan resulted in a comparatively low risk of adverse hemodynamic effects (left ventricular systolic pressure). Although our results suggested the attenuation of PAH severity in all treatment groups, PAH could not be reversed.

Background: Closure of PDA can be associated with echocardiographic changes including deterioration of LV systolicfunction. Although PDA is commonly encountered in dogs, few comprehensive reports of echocardiographic changes in dogswith PDA closure are available.Objectives: To evaluate the short-term echocardiographic changes observed after PDA closure in dogs using strain analysis.Animals: Seventeen client-owned dogs with left-to-right PDA.Methods: Echocardiographic evaluations, including standard echocardiography and two-dimensional tissue tracking(2DTT), were performed before and within 3 days of PDA closure.Results: Preclosure examination showed LV and left atrial dilatation indicating volume overload as a result of PDA. Clo-sure of PDA resulted in significant reduction of LVIDd (

A 3-year-old, 5 kg, male Toy Poodle with a mast cell tumor on the left pelvic limb was referred to Tokyo University of Agriculture and Technology Animal Hospital for an oncologic evaluation. On physical examination, a continuous bruit was auscultated over the left inguinal region with a palpable thrill. Cardiac auscultation identified a grade II/VI systolic and a grade I/VI diastolic murmur over the mitral and the aortic valves, respectively. No signs of peripheral cyanosis or congestion were noted. On thoracic radiographs, moderate, generalized enlargement of the cardiac silhouette was observed without evidence of pulmonary edema or pleural effusion. Color Doppler echocardiography identified mild pulmonic, mitral, and aortic valve regurgitation. Measurements of the left ventricle (LV) indicated an increased internal diameter with normal LV wall and septal thicknesses, normal fractional shortening and mild left atrial (LA) enlargement, with normal sinus rhythm. Normal mean arterial blood pressure was obtained on the thoracic limb using the oscillometric method. Laboratory test results (complete blood count, serum biochemistry profile, electrolytes, coagulation profile) were within the normal reference ranges. Ultrasonography of the caudal abdomen showed a caudal vena cava (CVC) with a diameter of 24.6 mm (dog

Background The effects of isosorbide dinitrate (ISDN) have not been sufficiently investigated in conscious dogs with mitral valve regurgitation (MR). Objective The objective was to investigate the effects of a sustained-release form of ISDN (sr-ISDN) on hemodynamics and the autonomic nervous system in dogs with MR. Animals Six healthy Beagles weighing 11.2 ± 2.2 kg (2 years of age; 2 males and 4 females) were used. Methods Experimental, crossover, and interventional study. Dogs with experimentally induced MR were administered placebo, 2, 5, and 10 mg/kg sr-ISDN PO on separate days with a 7-day washout period between randomized dosings. Left atrial pressure (LAP) had been recorded continuously from 30 minutes before administration of sr-ISDN to 12 hours after administration. Results LAP was significantly decreased after administration in the 5 and 10 mg/kg groups. Significant decrease was observed at 3 and 4 hours after administration in the 5 mg/kg group. In the 10 mg/kg group, significant decrease was observed at 2, 3, 4, 5, 6, 7, 10, and 11 hours after administration. The lowest value was observed at 4 hours after administration in the 5 and 10 mg/kg groups (20.9 ± 4.2 to 15.9 ± 3.9 mmHg, P

The purpose of the present study is to investigate the effect of postural change on transesophageal echocardiography (TEE) views and parameters of interest anesthesia monitoring in healthy dogs. Twelve Beagle dogs were anesthetized and randomly positioned in one of four postures: right lateral-recumbency, left lateral-recumbency, supine position and prone position. After examinations in one posture, the same examination was demonstrated in another posture and repeated in all postures. In each posture, several standard TEE views were demonstrated: longitudinal cranial-esophageal aorta long-axis-view, transverse middle-esophageal mitral valve long-axis-view and transgastric middle short-axis-view. Additionally, echocardiographic parameters were attempted to measure, and direct blood pressure monitoring was performed in each view. As a result, oriented views, except for transgastric middle short-axis-view, could be obtained in all postures. Stroke volume and peak early diastolic velocity of mitral inflow were lower in supine position compared with those in right and left lateral-recumbency. Heart rate (HR) and systemic vascular resistance were higher in supine position compared with those in right and left lateral-recumbency. Left ventricular pre-ejection period/left ventricular ejection time corrected and uncorrected by HR were higher in supine position compared with those in right and left lateral-recumbency. In conclusion, longitudinal cranial-esophageal aorta long-axis-view and transverse middle-esophageal mitral valve long-axis-view provide useful information of interest anesthesia monitoring, because of their views enable to certainly obtain TEE parameters in various postures. Furthermore, TEE parameters allow to detect the changes of preload, afterload and HR that occur in supine position dogs.

This study aimed to investigate the potential effects of sildenafil on pulmonary hypertension (PH) in the monocrotaline (MCT)-induced PH rat. Twenty-four, 12-week-old, male Sprague-Dawley rats were injected with MCT or saline solution. After injection of MCT, rats received oral sildenafil immediately (early-phase treatment group: E group), 4 weeks after injection (late-phase treatment group: L group) or no treatment (MCT group) until 6 weeks after injection. Serial echocardiography and right ventricular systolic pressure (RVSP) measurements via a cardiac catheter were performed. RVSP was reduced in the E and L groups compared with the MCT group. Echocardiography indicated that sildenafil therapy prevents an increase in RVSP and preserves diastolic function, and this effect is not dependent on timing of initiation of therapy.

The present study aimed to evaluate the preventive effect of sildenafil treatment on pulmonary hypertension (PH) induced by monocrotaline (MCT) in rats. Fifty-four 12-week-old male Sprague-Dawley rats were injected with MCT or saline solution (MCT-injected rats: n=36; saline: n=18). Serial echocardiography and right ventricular systolic pressure (RVSP) measurements via a cardiac catheter were performed at 2, 4 and 6 weeks after the injection. After injection of MCT, rats received oral sildenafil (MCT/sildenafil group: n=18) or no treatment (MCT group: n=18) until undergoing echocardiography and cardiac catheterization. RVSP in the MCT/sildenafil group was lower than that in the MCT group at 4 (P

The hearts of seven elderly dogs in which bradycardia-tachycardia syndrome (BTS) had been diagnosed electrocardiographically were examined post mortem. The clinical basis of the underlying heart disease was invariably mitral or mitral and tricuspid regurgitation. Microscopical examination of the sinoatrial (SA) node and the SA junctional region consistently revealed depletion of SA nodal cells, with a corresponding increase in fibrous or fibro-fatty tissue that interrupted contiguity between the SA node and the surrounding atrial myocardium. The left and right atrial walls showed an increased amount of fibrous tissue in the myocardium and disruption of the muscle bundle architecture (interstitial myocardial fibrosis) to varying degrees. Qualitatively, these changes in the SA node and the SA node region resembled those associated with ageing in elderly people with or without BTS. Thus, it is possible that the pathological process affecting the SA node in these dogs was fundamentally related to ageing and may have caused BTS, in combination with atrial myocardial lesions caused by mitral and tricuspid regurgitation.

An 11-month-old, 3 kg, female domestic shorthair cat was referred to evaluate cardiac structure and function. Echocardiography revealed the membrane dividing the left atrium into two chambers, a large defect in the lower part of the atrial septum, and turbulent blood flow from the distal left atrium into the right atrium. These findings suggested cor triatriatum sinister (CTS) with incomplete atrioventricular septal defect (AVSD). The cat was treated with medications for management of congestive heart failure. In the end, she died from right-sided heart failure 17 months after the initial presentation. At necropsy, a fibromuscular membrane with a round orifice in the left atrium and an ostium primum defect were confirmed, and the definitive diagnosis of CTS with incomplete AVSD was made. To our knowledge, this study presents the first case report of CTS with incomplete AVSD in a cat.

Background: Despite many epidemiological reports concerning the efficacy of angiotensin-converting enzyme (ACE) inhibitors in dogs with mitral regurgitation (MR), the hemodynamic effects of ACE inhibitor administration have not been fully evaluated. Objectives: To document left atrial pressure (LAP) in dogs with MR administered ACE inhibitors, in order to obtain interesting information about daily LAP changes with administration of ACE inhibitors. Animals: Five healthy Beagle dogs weighing 9.8 to 14.2 kg (2 males and 3 females; aged 2 years). Methods: Experimental, crossover, and interventional study. Chordae tendineae rupture was induced, and a radiotelemetry transmitter catheter was inserted into the left atrium. LAP was recorded for 72 consecutive hours during which each of 3 ACE inhibitors—enalapril (0.5 mg/kg/d), temocapril (0.1 mg/kg/d), and alacepril (3.0 mg/kg/d)—were administered in a crossover study. Results: Averaged diurnal LAP was significantly, but slightly reduced by alacepril (P= .03, 19.03 ± 3.01–18.24 ± 3.07 mmHg). The nightly drops in LAP caused by alacepril and enalapril were significantly higher than the daily drops (P= .03, −0.98 ± 0.19 to −0.07 ± 0.25 mmHg, and P= .03, −0.54 ± 0.21–0.02 ± 0.17 mmHg, respectively), despite the fact that the oral administrations were given in the morning. Systolic blood pressure (122.7 ± 14.4–117.4 ± 13.1 mmHg, P= .04) and systemic vascular resistance (5800 ± 2685–5144 ± 2077 dyne × s/cm5, P= .03) were decreased by ACE inhibitors. Conclusions and Clinical Importance: ACE inhibitors decrease LAP minimally, despite reductions in left ventricular afterload. ACE inhibitors should not be used to decrease LAP.

We examined whether right ventricle-pulmonary artery valved conduit (RPVC) implantation can overcome the disadvantages of current procedures for pulmonic stenosis (PS). We histologically evaluated the feasibility of RPVC using a homograft in PS model dogs. Eight dogs underwent pulmonary artery banding (PAB) and then 12 weeks later were assigned to PAB (n=4) or PAB+RPVC (n=4) groups. Dogs in the PAB group received no treatment throughout the experimental period, whereas the PAB+RPVC group underwent RPVC. At 1 year after PAB, hearts and conduits were explanted from euthanized dogs and histologically evaluated. The ratios (%) of myocardial fibrosis on right ventricle (RV) epicardial, median and endocardial layers were significantly lower in the PAB+RPVC, than in the PAB group. The ratio of myocardial fibrosis on left ventricular (LV) epicardial and endocardial layers were significantly lower in the PAB+RPVC, than in the PAB group. Neo-intimal thickness in the anastomosis areas of the Denacol and PAB+RPVC groups was 42.77 +/- 30.19 and 88.30 +/- 27.24 microm, respectively, with no significant differences between the groups. Calcification and neo- intima hypertrophy were not obvious in the valve area. Immunohistological staining showed that the internal surface of the anastomosis and intermediate areas were positive for endothelial cells. We concluded that RPVC using a bioprosthetic graft can apparently overcome the disadvantages of current procedures for pulmonic stenosis.

Right ventricle (RV)-pulmonary artery (PA) valved conduit (RPVC) implantation decreases RV systolic pressure in pulmonic stenosis (PS) by forming a bypass route between the RV and the PA. The present study evaluates valved conduits derived from canine aortae in a canine model of PS produced by pulmonary artery banding (PAB). Pulmonary stenosis was elicited using PAB in 10 conditioned beagles aged 8 months. Twelve weeks after PAB, the dogs were assigned to one group that did not undergo surgical intervention and another that underwent RPVC using denacol-treated canine aortic valved grafts (PAB+RPVC). Twelve weeks later, the rate of change in the RV-PA systolic pressure gradient was significantly decreased in the PAB+RPVC, compared with the PAB group (60.5 +/- 16.7% vs. 108.9 +/- 22.9%; p0.01). In addition, the end-diastolic RV free wall thickness (RVFWd) was significantly reduced in the PAB+RPVC, compared with the PAB group (8.2 +/- 0.2 vs. 9.4 +/- 0.7 mm; p0.05). Thereafter, regurgitation was not evident beyond the conduit valve and the decrease in RV pressure overload induced by RPVC was confirmed. The present results indicate that RPVC can be performed under a beating heart without cardiopulmonary bypass and adapted to dogs with various types of PS, including "supra valvular" PS or PS accompanied by dysplasia of the pulmonary valve. Therefore, we consider that this method is useful for treating PS in small animals.

Feline morbillivirus (FmoPV) is a new virus species and its detection is important, since correlation has been reported between FmoPV virus infection and tubulointerstitial nephritis in cats. Here, we report a real-time reverse transcription (RT)-PCR system that can detect the FmoPV L-gene sequence with more than 10-time higher sensitivity than a conventional PCR system, resulting in detection of less than 10 copies of the template DNA. The total FmoPV positive rate of urine samples from veterinary clinics and hospitals in Japan was 15.1% (25/166) using this system. This study demonstrates usefulness of the real-time RT-PCR system for detection of FmoPV for cat urine samples.