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This study retrospectively evaluated the fentanyl-sparing effect of ultrasound-guided proximal radial, ulnar, median, and musculocutaneous nerve (RUMM) block for radial and ulnar fracture repair in dogs. Fentanyl was prepared for intraoperative analgesia in dogs, although proximal RUMM block was performed using 0.5% or 0.25% bupivacaine before surgery in the block group. Dogs without a nerve block were assigned to the control group. The fentanyl dose in the block group [0.8 (0-1.9) μg/kg/hr] [median (interquartile range)] was significantly lower than in the control group [8.4 (7.2-10) μg/kg/hr]. Surgery was performed without fentanyl in50% of the dogs (5/7), using 0.5% bupivacaine. Ultrasound-guided proximal RUMM block can be useful as an intraoperative analgesic for radial and ulnar fracture repair in dogs.

Each 5 urothelial carcinoma (UC) cell lines with and without the v-Raf murine sarcoma virus oncogene homolog B (BRAF) gene mutation (V595E) were established and examined V595E-related tumorigenic characteristics in dogs. No typical morphological features were observed in cloned cells with and without V595E. The cell proliferation of both cloned cells showed logarithmic growth curve and those doubling time were 24.9 ± 4.1 h in V595E ( +) and 29.3 ± 11.3 h in V595E ( −). On the growth curve of xenotransplanted tumor in severe combined immunodeficiency mice, 3 out of 5 V595E ( +) and 2 out of 5 V595E ( −) cloned cells revealed gradually and remarkably increasing curve, indicating clearly tumorigenicity. The xenotransplanted tumors with V595E ( +) showed typical features of UC, such as solid proliferation of pleomorphic tumor cells, formation of papillary structure, and glandular structure. Additionally, various vascular formation was observed, probably indicating an advanced growth phase of UC. In mitogen-activated protein kinase (MAPK) signaling pathway, cytoplasmic phosphorylated-BRAF (pBRAF) and cytoplasmic and nuclear phosphorylated-ERK1/2 (pERK1/2) were detected in all 4 tumors with V595E ( +), whereas only cytoplasmic and nuclear pERK1/2 was detected in tumors with V595E ( −). Since V595E can directly activate MAPK signaling pathway, coincidence of V595E with pBRAF (phosphor Thr598/Ser601) indicates acquired resistance to BRAF inhibitors. These established UC cell lines, especially V595E ( +) cell lines, are useful tool for understanding pathophysiological states and controlling therapeutic manners of UC in dogs.

A large abdominal mass was found in a dog. Histopathologically, the surface of the mass was covered with compressed adrenal gland tissue. The neoplastic cells showed typical features of malignant peripheral nerve sheath tumor (MPNST), including Antoni type A and type B pattern, and nuclear palisading. Immunohistochemically, these cells were positive for S100 protein, nerve growth factor receptor, nestin and claudin-1. The dog was euthanized because of the developing multiple metastatic lesions. The metastatic cells showed quite similar histopathological and immunohistochemical features as those in the original tumor. Although MPNST can develop at many body sites, this is the first report of MPNST originating from the adrenal gland in a dog.

A novel cell line of canine medullary thyroid carcinoma (MTC) was established from the neck mass, diagnosed histopathologically and immunohistochemically as ectopic MTC. The neoplastic cells arranging trabecular structures were characterized as pleomorphic cells with eosinophilic cytoplasm and nucleus, containing often clear nucleolus. These tumor cells were immuno-positive for calcitonin gene–related protein (CGRP), somatostatin, and chromogranin A. In addition, 8th passaged cultured cells were also immuno-positive for CGRP, somatostatin, and chromogranin A. The cloned tumor cells showed logarithmic cell growth with a doubling time of 33.3 h. From the results of DNA sequencing of rearranged during transfection (RET) proto-oncogene, the cloned tumor cells had four single base substitution, including exon 5 codon 82, exon 16 codon 750, exon 17 codon 777, and exon 24 codon 1085, all of which were single nucleotide polymorphism reported in RET gene of dogs. After the xenotransplantation into severe combined immunodeficiency (SCID) mice, the cloned cells showed tumorigenicity potentials. The morphological and immunohistochemical features of the xenotransplanted tumor were almost in conformity with those of the original tumor, including positive immunoreactivity for calcitonin, CGRP, and chromogranin A. To our knowledge, this is the first report of canine MTC cell line, which provides useful in vitro tool for understanding oncogenic mechanism and pathophysiological state of MTC in dogs.

A 22-month-old, male Labrador retriever was presented with anorexia, dyspnoea, and fainting. The dog was diagnosed with a double-chambered right ventricle and tricuspid valve dysplasia using echocardiography and cardiac catheterisation. A marked bilateral pleural effusion was also present and chemical analysis of the fluid confirmed the diagnosis of chylothorax. Using echocardiography, a pressure gradient of 87.1 mmHg was found between the proximal and distal chambers of the double-chambered right ventricle. Initiation of cardiopulmonary bypass allowed the anomalous muscle bundle that divided the right ventricle into two chambers to be resected via a right ventriculotomy. The fainting completely resolved postoperatively, and this treatment seemed quite effective in the reduction of pressure overload ascribable to ejection disturbance. Because the tricuspid dysplasia was not corrected in the first operation, the postoperative chyle effusion was reduced but did not cease. A combination of thoracic duct ligation and passive pleuroperitoneal shunting was effective in the resolution of the chyle effusion.

Objective— To compare right atrium incision (RAI) and right ventricular outflow incisions (RVI) for surgical repair of membranous ventricular septal defect (VSD) facilitated by cardiopulmonary bypass (CPB). Study Design— Retrospective study. Animals— Dogs (n=10) with VSD. Methods— Medical records of dogs that had VSD repair were reviewed. Membranous VSD without any malformation and abnormality was confirmed on several clinical examinations and by angiocardiography. RAI (5 dogs) and RVI (5 dogs) was used for VSD access and repair facilitated by CPB. Procedure comparison was by surgical duration, postoperative recovery period, and occurrence of postoperative arrhythmia. Results— Duration of surgery was similar for RAI and RVI; however, postoperative recovery time was significantly reduced with RAI. Significant moderate operative damage occurred with right atrium incision. Conclusions— Right atrium incision was more effective than RVI for repair of membranous VSD using CPB. Clinical Relevance— RAI should be considered in preference to RVI for repair of membranous VSD using CPB.

Recent studies have demonstrated the benefits of nitric oxide (NO) on myocardial hypertrophy and myocardial fibrosis. It was suggested that NO has a protective effect on myocardial cell through the neurohormonal system. This effect serves to highlight the important role of NO in maintaining the function and form of heart with chronic heart failure. However, there are no known reports about on the effect of prolonged administration of nitrate on pressure over-load heart. This study was conducted to examine the long-term effect of oral nitrate therapy in rats with pressure-overloaded heart. An abdominal aorta constricted (AC) model of pressure-overloaded heart was created in male Wistar rats. Sustained release isosorbide dinitrate (sr-ISDN) (5 mg/kg once a daily) was administered to the rats once a daily for 12 weeks. The animals were euthanized during the study period, and the heart was collected and weighed. Histopathological examination was performed to evaluate the effect of sr-ISDN on myocardial hypertrophy and fibrosis. The ratio of heart to body weight increased significantly in AC rat and this increase was significantly prevented by sr-ISDN treatment. Histopathological examination showed significant increase in fibrotic area of AC rat compared to sham rat, this increase was inhibited by sr-ISDN treatment. Cardiomyocyte transverse diameter was significantly increased in AC rat compared with sham rat, but this increase tended to decrease by sr-ISDN treatment. In conclusion, intermittent administration with sr-ISDN has mild effect in inhibiting cardiac hypertrophy and marked effect in inhibiting fibrosis due to pressure-overload.

A 4-month-old male French Bulldog weighing 5.0 kg (11 lb) was referred for a heart murmur. A grade 3/6 systolic murmur was detected at the left heart base and a grade 4/6 systolic murmur was detected at the right heart base. By use of color-flow Doppler ultrasonography and cardiac catheterization, a diagnosis of supracristal ventricular septal defect (VSD) with accompanying aortic regurgitation was made. Percutaneous transcatheter coil embolization was used to close the VSD. Because residual shunt was detected via echocardiography after coil implantation, the residual shunt was followed periodically via echocardiography to detect spontaneous closure of the VSD. Volume overload in the left ventricle was detected in the dog 131 days after admission. Additional coils were placed 137 days after admission. Hemolysis resulting in hemoglobinuria was detected, but this complication was mild. In the dog of this report, results of coil occlusion for correction of VSD were promising. Thus, coil occlusion should be considered as an alternative treatment for VSD in dogs.

A three-month-old male Golden Retriever had symptoms including exercise intolerance, dyspnea and syncope and was diagnosed with subvalvular aortic stenosis. Cardiac catheterization revealed a left ventricular-aortic systolic pressure gradient of 90 mm Hg. Surgical correction of the condition was achieved using cardiopulmonary bypass. The subvalvular fibrous lesion was resected through an aortotomy. The stenosis was dilated from 8.5 mm to 12.0 mm in diameter. Postoperatively the dog was asymptomatic. Seven months after surgery, the pressure gradient decreased to 44 mm Hg. However, after another three months, the dog died suddenly without any premonitory signs. Postmortem examination revealed that pathologic changes caused by increased left ventricular pressure overload were not severe.

The goal of the current study was to compare the efficiency of gas exchange and platelet conservation of a new extracapillary blood flow oxygenator versus an endocapillary blood flow oxygenator during open heart surgery with extracorporeal circulation in dogs. Dilation and remodeling of the right ventricular outflow tract of dogs was performed using a patch graft technique to simulate pulmonary stenosis. Sequential pre- and post-operative blood analysis revealed that gas exchange efficiency and platelet conservation was significantly greater with the extracapillary blood flow oxygenator than with the endocapillary blood flow oxygenator. However, the priming volume of the extracapillary blood flow oxygenator was significantly greater, leading to hemodilution. We conclude that while the extracapillary blood flow oxygenator provided benefits in terms of gas exchange and platelet conservation, development of a smaller extracapillary blood flow type oxygenator to reduce hemodilution effects would be beneficial.

A 10-year old male mongrel dog was presented to the University Veterinary Teaching Hospital with a two-month history of episodic syncope. Twenty-four hr Holter electrocardiographic (ECG) recording revealed frequent episodes of advanced atrioventriculer block with long periods of ventricular asystole. The cause of syncope was determined to be Adams-Stokes syndrome exhibited bradyarrhythmia. After the animal failed to respond to medical therapy, permanent transvenous pacemaker implantation was performed. Postoperative Holter ECG showed 100 beat per min programmed pacemaker rhythm, which indicated successful capture of the artificial pacing. The dog recovered smoothly from the operation and syncopal episodes completely disappeared. Six months after the surgery, no complications were observed and the dog's quality of life has dramatically improved.

A seven-year-old, female, domestic short hair cat was presented with a history of chronic anorexia. Radiographic examination revealed a large space-occupying calcified mass in the abdominal cavity. The mass was located in pylorus and did not extend into the duodenum and surrounding tissues. Billroth I gastroduodenostomy was conducted to remove the mass. Histopathological examination of the mass showed a lymphoma. Although Recovery following the operation was excellent, the patient showed intermittent vomiting unrelated to feeding. Radiographical examination revealed a megaesophagus, which was assumed to be a complication of the Billroth I procedure, since the condition was not observed before the procedure.

An 8-month-old entire Miniature Dachshund, weighing 4.2 kg, was presented for examination following delvelopment of a cough. Ventricular septal defect had been diagnosed tentatively in its infancy on the basis of a cardiac murmur detected by auscultation and echocardiography. Echocardiography using a B mode right parasternal long-axis view showed a defect at the atrioventricular junction and a thickened cusp of the aortic valve prolapsing into the defect. Colour-flow Doppler showed shunt blood flow across the defect at the level of the atrioventricular junction, from left to right. The sinus of Valsalva was dilated, with turbulent blood flow. Aortic regurgitation was also observed. Cardiac catheterisation studies confirmed the diagnosis of a supracristal ventricular septal defect with aortic regurgitation. Despite medication with digoxin, enalapril and aminophylin, started from the first admission, left ventricular internal dimensions gradually increased, and fractional shortening of the left ventricle gradually decreased. Surgery, with the aid of extracorporeal circulation, to close the ventricular septal defect, was performed 1 year after the initial examination. The aortic valve was left untreated. Postoperatively, the systolic murmur disappeared. Shunt flow from the left to the right ventricle was no longer observed on echocardiography, however there was still a small amount of aortic regurgitation during diastole visualised with colour-flow Doppler echocardiography. The prolapse of the cusp of the aortic valve on B-mode echocardiography was no longer observed and thickening of the cusp had not progressed. Left ventricular function measurement using M mode echocardiography showed a reduced left ventricular volume overload with reduced left ventricular internal dimensions and increased fractional shortening. The cough was relieved and no follow-up medication was scheduled. Early surgical closure of the ventricular septal defect improved the patient's condition and controlled prolapse and thickening of the aortic valve.

Recently, it has been reported that intermittent administration of nitrate, with a nitrate-free interval of 10 to 12 hr eliminated expression of tolerance, and maintained its hypotensive effect. In the present study, we evaluated whether nitrate tolerance developed or not with an intermittent administration of sr-ISDN (5 mg/kg/ once a day) in Wistar rats. The effect of this administration protocol for sr-ISDN on the volume overload heart model, aortovenous fistula, was also examined. Furthermore, blood pressure was monitored by radio telemetry during sr-ISDN (5 mg/kg/once a day) administration. Nitrate tolerance did not develop, and eccentric hypertrophy due to volume overload was moderated by sr-ISDN administration. Sr-ISDN administration maintained blood pressure lower level than the placebo group. In conclusion, prolonged intermittent administration of sr-ISDN maintained its hypotensive effect during the entire experiment period, without developing tolerance, and moderated efferent hypertrophy with attenuated volume overload.

A new valved conduit was developed using a canine aortic valve. The bioprosthetic valve was fixed with glutaraldehyde and epoxy compound (Denacol-EX313/810). A vascular graft composed of ultra-fine polyester fiber (10 mm in diameter, 200 mm in length) was used. Four dogs underwent apico-aortic valved conduit (AAVC) implantation and aortic banding (bypass group, BG), while another 4 dogs underwent aortic banding without AAVC implantation (control group, CG). Cardiac catheterization and angiocardiography were performed for assessment of hemodynamics 2 weeks and 6 months after surgery. Left ventricular systolic pressure, left ventricular end-diastolic pressure and the left ventricular-aortic pressure gradient differed significantly (P

In veterinary medicine, dopamine is currently being administered clinically by infusion for treatment of kidney disorders at low doses (or = 3 microg/kg/min) and for assessment of hemodynamics at high doses (or = 5 microg/kg/min). However, since high doses of dopamine cause peripheral vasoconstriction due to its effect on alpha adrenoceptors, high doses have no longer been recommended. The present study was conducted to explore possible regimens for the use of dopamine infusion in dogs. The regional (renal and cardiac) blood flow for 60 min was measured by using colored microspheres at three doses (3, 10 and 20 microg/kg/min) of dopamine infusion in healthy anesthetized mongrel dogs. The effects on kidney and peripheral hemodynamics at each dose and the resultant cardiac output, mean arterial blood pressure and total peripheral resistance were determined. Renal blood flow increased markedly at 3 microg/kg/min dopamine. Improvement in hemodynamics indicated by marked increase in cardiac blood flow, cardiac output and mean arterial blood pressure and decreased total peripheral resistance was observed at higher doses (10 and 20 microg/kg/min). At 10 microg/kg/min, in addition to the satisfactory increase in cardiac blood flow, there was also a stable satisfactory increase in renal blood flow. However, at 20 microg/kg/min, increased myocardial oxygen consumption (manifested by marked increased in cardiac output), arrythmia and irregular increase in renal blood flow were detected. This study suggests that the clinical use of dopamine infusion in dogs could be safely expanded to moderately higher doses.

Fifteen and eight mature beagles, without (normal group) and with experimental mitral regurgitation (MR group), respectively, were given 0.02 mg /kg/day digoxin powder for 10 days orally. The optimum time for sample collection after administration of digoxin was observed to be 8-18 hr and 10-22 hr in the normal and MR groups, respectively. In both groups, a stable concentration was reached after 3-5 days of treatment. No differences in plasma level were observed between sexes. The optimum concentration of digoxin was attained at an earlier stage than has been previously reported for both dogs and humans.

A shiba inu dog with marked abdominal distension was diagnosed with cor triatriatum dexter and surgical correction was performed under extracorporeal circulation. The total duration of cardiac arrest was 11 minutes and total perfusion time was 34 minutes. The dog had an uneventful postoperative recovery. Postoperative contrast radiography of the caudal vena cava revealed normal flow into the right heart. Abdominal distension was no longer observed. Although several methods have been used to treat cor triatriatum dexter in dogs, the authors consider surgical correction under extracorporeal circulation to be a reliable approach.