• Journal of Veterinary Science
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• v.21 no.5
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• pp.75.1-75.8
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• 2020

Background: Dental diseases are common in dogs and cats, and accurate measurements of dentoalveolar structure are important for planning of treatment. The information that the comparison computed tomography (CT) with dental radiography (DTR) is not yet reported in veterinary medicine. Objectives: The purpose of this study was to compare the DTR with CT of dentoalveolar structures in healthy dogs and cats, and to evaluate the CT images of 2 different slice thicknesses (0.5 and 1.0 mm). Methods: We included 6 dogs (2 Maltese and 1 Spitz, Beagle, Pomeranian, mixed, 1 to 8 years, 4 castrated males, and 2 spayed female) and 6 cats (6 domestic short hair, 8 months to 3 years, 4 castrated male, and 2 spayed female) in this study. We measured the pulp cavity to tooth width ratio (P/T ratio) and periodontal space of maxillary and mandibular canine teeth, maxillary fourth premolar, mandibular first molar, maxillary third premolar and mandibular fourth premolar. Results: P/T ratio and periodontal space in the overall dentition of both dogs and cats were smaller in DTR compared to CT. In addition, CT images at 1.0 mm slice thickness was generally measured to be greater than the images at 0.5 mm slice thickness. Conclusions: The results indicate that CT with thin slice thickness provides more accurate information on the dentoalveolar structures. Additional DTR, therefore, may not be required for evaluating dental structure in small-sized dogs and cats.

• Journal of Veterinary Science
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• v.21 no.1
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• pp.10.1-10.12
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• 2020

Blood perfusion of skeletal muscle and callus was evaluated using contrast-enhanced ultrasonography (CEUS) in a canine osteotomy model to determine the applicability of CEUS in the assessment of neovascularization during fracture healing and to compare the vascular signals on CEUS between external skeletal fixation and cast-applied dogs. In 6 Beagle dogs, a simple transverse osteotomy was performed at the left tibial shaft and external skeletal fixation (n = 3) or a cast (n = 3) was applied. Radiography, power Doppler ultrasonography (power Doppler), and CEUS were performed until complete union was achieved. On CEUS, vascular changes were quantitatively evaluated by measuring peak intensity (PI) and time to PI in the soft tissue and callus and by counting the vascular signals. Vascular signals from the soft tissue were detected on power Doppler and CEUS on day 2. Significantly more vascular signals were detected by CEUS than by power Doppler. On CEUS, PI in the surrounding soft tissue was markedly increased after the fracture line appeared indistinctively changed on radiography in all dogs. In the cast-applied dogs, vascular signals from the periosteal and endosteal callus were detected on CEUS before mineralized callus was observed on radiography. CEUS was useful in assessing the vascularity of soft tissue and callus, particularly in indirect fracture healing, and provided indications of a normally healing fracture.

• Journal of Veterinary Science
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• v.23 no.6
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• pp.68.1-68.8
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• 2022

Background: Studies on anesthetized dogs regarding pulse pressure variation (PPV) are increasing. The influence of respiratory rate (RR) on PPV, in mechanically ventilated dogs, has not been clearly identified. Objectives: This study evaluated the influence of RR on PPV in mechanically ventilated healthy dogs after hemorrhage. Methods: Five healthy adult Beagle dogs were premedicated with intravenous (IV) acepromazine (0.01 mg/kg). Anesthesia was induced with alfaxalone (3 mg/kg IV) and maintained with isoflurane in 100% oxygen. The right dorsal pedal artery was cannulated with a 22-gauge catheter for blood removal, and the left dorsal pedal artery was cannulated and connected to a transducer system for arterial blood pressure monitoring. The PPV was automatically calculated using a multi-parameter monitor and recorded. Hemorrhage was induced by withdrawing 30% of blood (24 mL/kg) over 30 min. Mechanical ventilation was provided with a tidal volume of 10 mL/kg and a 1:2 inspiration-to-expiration ratio at an initial RR of 15 breaths/min (baseline). Thereafter, RR was changed to 20, 30, and 40 breaths/min according to the casting lots, and the PPV was recorded at each RR. After data collection, the blood was transfused at a rate of 10 mL/kg/h, and the PPV was recorded at the baseline ventilator setting. Results: The data of PPV were analyzed using the Friedman test followed by the Wilcoxon signed-rank test (p < 0.05). Hemorrhage significantly increased PPV from 11% to 25% at 15 breaths/min. An increase in RR significantly decreased PPV from 25 (baseline) to 17%, 10%, and 10% at 20, 30, and 40 breaths/min, respectively (all p < 0.05). Conclusions: The PPV is a dynamic parameter that can predict a dog's hemorrhagic condition, but PPV can be decreased in dogs under high RR. Therefore, careful interpretation may be required when using the PPV parameter particularly in the dogs with hyperventilation.

• Journal of Veterinary Clinics
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• v.40 no.2
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• pp.104-112
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• 2023

The change in the position of the abdominal organs due to movement by respiration is one of the reasons behind inaccurate irradiation of organs during radiotherapy (RT). Although studies in human medicine have revealed on the respiratory movements of abdominal organs, there is little information and no reference data for dogs. The purpose of this study was to establish the reference values of abdominal organs movement in various postures using computed tomography (CT), and to compare the movements of organs between dorsal recumbency and ventral, right and left lateral recumbency during respiration. CT images for kidney, adrenal gland, medial iliac lymph node, urinary bladder, gallbladder, liver, stomach, and thoracic and lumbar vertebral body of five beagle dogs were acquired. The movements of organs were evaluated by comparing the end-expiratory and end-inspiratory images. Movements of the organs were evaluated by dividing it into right-to-left, dorsal-to-ventral, and cranial-to-caudal directions. The movements of abdominal organs according to the change in postures and respiration were establish. The movement of the bilateral organs was the least when the organs were in the downward position (p < 0.017). The movement of cranial-to-caudal direction was greater than the movement of the other directions in most of the organs. Data obtained in this study may be useful in selecting the appropriate posture that can reduce the movements of organs to be treated with RT, and the data could be useful for setting the planning target volume to consider the movements of the abdominal organs by respiration.

• Journal of Veterinary Clinics
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• v.40 no.4
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• pp.283-287
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• 2023

A 10-year-old spayed female beagle dog presented with a 2-month history of third-eyelid elevation in the left eye (OS). Ophthalmic examination revealed slightly diminished corneal and palpebral reflexes along with exophthalmos in the OS. Schirmer's tear test and intraocular pressure values were within the normal range for the OS. Slit-lamp biomicroscopy revealed protrusion of the third eyelid and corneal opacity in the OS. Fundoscopy revealed a prominent black mass in the OS covering the optic nerve. Tapetal hyper-reflectivity was also observed around the mass. Ocular ultrasonography showed a 0.74 × 0.67 cm echogenic posterior segment mass around the optic nerve protruding into the retrobulbar space. Computed tomography revealed a contrast-enhanced soft tissue lesion in the posteromedial aspect of the left eyeball protruding into the retrobulbar region, and the optic nerve was suspected to be involved. No evidence of osteolytic changes in the adjacent bone or distant metastasis was observed. Enucleation was performed to prevent potential metastasis or local invasion of the mass and to relieve discomfort due to exposure to keratopathy resulting from lagophthalmos. Histopathological examination revealed a central choroidal melanocytoma extending into the optic nerve. No local recurrence was detected until 16 months postoperatively.

• Journal of Veterinary Clinics
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• v.39 no.6
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• pp.311-318
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• 2022

Appropriate suture technique is crucial for successful tracheal anastomosis. However, standards for an ideal suture method have not yet been established. A previous study suggested tracheal anastomosis using barbed sutures that do not require knots; however, their use in small animals has not been reported. In this study, we aimed to compare knotless barbed sutures with conventional smooth sutures in terms of maximum tensile strength and suturing time in canine tracheal models to demonstrate the feasibility of using barbed sutures in tracheal anastomosis in dogs. Tracheal segments harvested from nine beagle dog cadavers were randomly assigned to three suture groups: barbed suture (B), smooth suture in simple interrupted pattern (SI), and smooth suture in simple continuous pattern (SC). The maximum tensile force and suturing time were compared according to the suturing method, and the mode of failure was evaluated. The average suturing time was 3.29 min in the B group; 4.41 min, SC group; and 8.99 min, SI group (p < 0.001). The average maximum tensile force in the SC group was 134.97 N, which was stronger than the SI (110.57 N) and B groups (103.10 N) (p < 0.05 and p < 0.01, respectively). The difference between the B and SI groups was not significant (p = 0.05). The B group demonstrated comparable mechanical strength and shorter suture time compared with the SI group. Therefore, tracheal anastomosis using barbed sutures could be an effective alternative to conventional smooth sutures in dogs.

• Journal of Animal Science and Technology
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• v.65 no.3
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• pp.550-561
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• 2023

This study investigated the effects of corn resistant starch (RS) on the anti-obesity properties, nutrient digestibility, and blood parameters in healthy beagles. Four spayed and six castrated beagle dogs were divided into a control group (CON) with a diet comprising rice and chicken meal and a treatment group (TRT) with a diet comprising corn with an increased RS content by heating-cooling and chicken meal. All dogs in the CON and TRT groups were fed a 1.2-fold higher energy diet than the daily recommended energy requirement for 16 weeks. Throughout the study period, the body weight of dogs in CON increased, whereas no change in body weight was observed in TRT, resulting in a significant difference in body weight between the two groups at the end of the experiment. Moreover, a significant reduction in the apparent total tract digestibility was observed upon the analysis of dry matter, nitrogen-free extract, and organic matter in TRT compared with that in CON. The complete blood cell composition and biochemical parameters were within the reference range in both groups. A significant increase in the concentration of serum adiponectin was found in TRT at the end of the experiment. These results suggest that the corn RS may be beneficial for weight management owing to its reduced nutrient digestibility.

• Journal of Periodontal and Implant Science
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• v.53 no.3
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• pp.207-217
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• 2023

Purpose: Non-crosslinked and crosslinked collagen membranes are known to exhibit distinct degradation characteristics, resulting in contrasting orientations of the adjacent tissues and different biological processes. The aim of this study was to conduct a histomorphometric assessment of non-crosslinked and crosslinked collagen membranes regarding neovascularization, tissue integration, tissue encapsulation, and biodegradation. Methods: Guided bone regeneration was performed using either a non-crosslinked (BG) or a crosslinked collagen membrane (CM) in 15 beagle dogs, which were euthanized at 4, 8, and 16 weeks (n=5 each) for histomorphometric analysis. The samples were assessed regarding neovascularization, tissue integration, encapsulation, the remaining membrane area, and pseudoperiosteum formation. The BG and CM groups were compared at different time periods using nonparametric statistical methods. Results: The remaining membrane area of CM was significantly greater than that of BG at 16 weeks; however, there were no significant differences at 4 and 8 weeks. Conversely, the neovascularization score for CM was significantly less than that for BG at 16 weeks. BG exhibited significantly greater tissue integration and encapsulation scores than CM at all time periods, apart from encapsulation at 16 weeks. Pseudoperiosteum formation was observed in the BG group at 16 weeks. Conclusions: Although BG membranes were more rapidly biodegraded than CM membranes, they were gradually replaced by connective tissue with complete integration and maturation of the surrounding tissues to form dense periosteum-like connective tissue. Further studies need to be performed to validate the barrier effect of the pseudoperiosteum.

• Journal of Veterinary Science
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• v.24 no.5
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• pp.65.1-65.9
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• 2023

Background: Bone subtraction computed tomography angiography (BSCTA) is a useful alternative technique for improving visualization of vessels surrounded by skull bone. However, no studies have compared computed tomography angiography (CTA) and BSCTA for improving the visibility of canine cerebral blood vessels. Objectives: To evaluate the potential benefit of BSCTA for better delineation of brain arteries of the circle of Willis (CoW) in dogs by comparing BSCTA with non-subtraction computed tomography angiography (NSCTA). Methods: Brain CTA was performed for nine healthy beagle dogs using a bolus tracking method with saline flushing. A total dose of 600 mgI/kg of contrast agent with an iodine content of 370 mgI/mL was injected at a rate of 4 ml/s. Bone removal was achieved automatically by subtracting non-enhanced computed tomography (CT) data from contrast CT data. Five main intracranial arteries of the CoW were analyzed and graded on a scale of five for qualitative evaluation. Results: Scores of basilar artery, middle cerebral artery, and rostral cerebral artery in the BSCTA group were significantly higher than those in the NSCTA group (p = 0.001, p = 0.020, and p < 0.0001, respectively). Scores of rostral cerebellar artery (RcA) and caudal cerebral artery (CCA) did not differ significantly between the two groups. However, scores of RcA and CCA in the BSCTA group were higher than those in the NSCTA group. Conclusions: BSCTA improved visualization of intracranial arteries of the CoW with close contact to bone. Thus, it should be recommended as a routine scan method in dogs suspected of having brain vessel disease.

• Journal of Veterinary Science
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• v.25 no.1
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• pp.2.1-2.14
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• 2024

Background: Sufficient surgical resection is necessary for effective tumor control, but is usually limited for vertebral tumors, especially in the cervical spine in small animal neurosurgery. Objective: To evaluate the primary stability and safety of customized three-dimensional (3D)-printed implants for cervical spine reconstruction after total vertebrectomy. Methods: Customized guides and implants were designed based on computed tomography (CT) imaging of five beagle cadavers and were 3D-printed. They were used to reconstruct C5 after total vertebrectomy. Postoperative CT images were obtained to evaluate the safety and accuracy of screw positioning. After harvesting 10 vertebral specimens (C3-C7) from intact (group A) and implanted spines (group B), implant stability was analyzed using a 4-point bending test comparing with groups A and C (reconstituted with plate and pins/polymethylmethacrylate after testing in Group A). Results: All customized implants were applied without gross neurovascular damage. In addition, 90% of the screws were in a safe area, with 7.5% in grade 1 (< 1.3 mm) and 2.5% in grade 2 (> 1.3 mm). The mean entry point and angular deviations were 0.81 ± 0.43 mm and 6.50 ± 5.11°, respectively. Groups B and C significantly decreased the range of motion (ROM) in C3-C7 compared with intact spines (p = 0.033, and 0.018). Both groups reduced overall ROM and neutral zone in C4-C6, but only group B showed significance (p = 0.005, and 0.027). Conclusion: Customized 3D-printed implants could safely and accurately replace a cervical vertebra in dog cadavers while providing primary stability.