Comparison between T2-weighted two-dimensional and three-dimensional fast spin-echo MRI sequences for characterizing thoracolumbar intervertebral disc disease in small-breed dogs.

Magnetic resonance imaging (MRI) is a standard test for diagnosis and treatment planning in dogs with degenerative thoracolumbar intervertebral disc disease (IVDD). However, published studies evaluating three-dimensional fast-spin echo (3D-FSE) pulse sequences for dogs with IVDD are currently limited. Aims of this retrospective, observational study were to compare findings from T2-weighted two- and three-dimensional fast spin-echo sequences (2D- and 3D-FSE, respectively) for a group of small breed dogs with thoracolumbar IVDD. Inclusion criteria were dogs with IVDD that underwent 1.5-Tesla MRI using both 2D-FSE and 3D-FSE sequences. For each dog and sequence, five pathologic indices were recorded: epidural fat discontinuation, vertebral canal compromise, spinal cord signal change, disc degeneration, and nerve root compression. Two independent investigators also scored visibility of the facet joint, intervertebral foramen, nerve roots, spinal cord grey-white matter differentiation, intervertebral discs, and epidural fat. The Wilcoxon signed-rank test was used to evaluate the between-sequence differences in pathologic indices and visibility scores. Interobserver agreement was measured using Cohen's weighted kappa along with 95% confidence intervals. A total of 21 dogs were sampled. The 3D-FSE sequences had higher pathologic indices of vertebral canal compromise (P = 0.020) and spinal cord signal change (P = 0.046) than 2D-FSE sequences. Furthermore, 3D-FSE sequences had higher visibility scores for the facet joint, intervertebral foramen, and nerve root structures (P < 0.001). Findings from the current supported the use of 3D-FSE sequences over 2D-FSE sequences for the evaluation of IVDD and visualization of spinal structures in small breed dogs.

Preoperative planning using computed tomography in tibial plateau levelling osteotomy: A comparison with conventional radiography.

BACKGROUND: Tibial plateau levelling osteotomy (TPLO) is currently one of the most common surgical procedures for the correction of the stifle joint with a ruptured cranial cruciate ligament. TPLO is based on the preoperative tibial plateau angle (TPA); therefore, it is essential to optimise the consistency and repeatability of TPA measurements. OBJECTIVES: This study aims to compare computed tomography (CT) with conventional radiography in the preoperative planning of TPLO. METHODS: This prospective study included six dogs (12 hindlimbs) and 13 canine cadaveric hindlimbs. In the six beagle dogs, TPAs were measured by three radiologists using digital radiographic and CT images to evaluate the intra- and inter-observer agreement. To evaluate the intra-observer agreement of the TPA before and after surgery, and the intended angle of the postoperative TPA according to the preoperative planning method, 13 cadaveric hindlimbs were evaluated thrice at random by a single radiologist. RESULTS: The intra- and inter-observer intraclass correlation coefficients (ICCs) of the CT method were higher than those of the radiographic method in normal beagle dogs. The intra-observer ICC of the CT method before and after TPLO was generally higher than that of the radiographic method in the cadaver. However, no significant difference was noted in the evaluation of the intended postoperative TPA according to the preoperative planning method. CONCLUSIONS: The intra- and inter-observer ICCs allowed for easy identification of landmarks required to consistently determine the TPA in the preoperative planning of TPLO based on CT images.

Effects of Confounding Factors on Liver Stiffness in Two-Dimensional Shear Wave Elastography in Beagle Dogs.

BACKGROUND: Two-dimensional shear wave elastography (2D-SWE) is a powerful technique that can non-invasively measure liver stiffness to assess hepatic fibrosis. PURPOSE: This study aimed to identify the effects of confounding factors, including anesthesia, breathing, and scanning approach, on liver stiffness when performing 2D-SWE in dogs. MATERIALS AND METHODS: Nine healthy Beagle dogs were included in this study. Hepatic 2D-SWE was performed, and liver stiffness was compared between conscious and anesthetized states, free-breathing and breath-holding conditions, and intercostal and subcostal approaches. For the anesthetized state, the breath-holding condition was subdivided into seven phases, which included forced-expiration (5 and 10 mL/kg), end-expiration (0 cm H2O), and forced-inspiration (5, 10, 15, and 20 cm H2O), and liver stiffness was compared among these phases. Changes in liver stiffness were compared between intercostal and subcostal approaches according to breathing phases. RESULTS: No significant difference was observed in liver stiffness between the conscious and anesthetized states or between the free-breathing and breath-holding conditions. No significant difference was noted in liver stiffness among the breathing phases, except for forced-inspiration with high airway pressure (15 and 20 cm H2O in the intercostal approach and 10, 15, and 20 cm H2O in the subcostal approach), which was associated with significantly higher liver stiffness (p < 0.05). Liver stiffness was significantly higher in the subcostal approach than in the intercostal approach (p < 0.05). Changes in liver stiffness were significantly higher in the subcostal approach than in the intercostal approach in all forced-inspiratory phases (p < 0.05). CONCLUSION: In conclusion, when performing 2D-SWE in dogs, liver stiffness is unaffected by anesthesia and free-breathing. To avoid inadvertent increases in liver stiffness, the deep inspiratory phase and subcostal approach are not recommended. Thus, liver stiffness should be interpreted considering these confounding factors.

Clinical evaluation of toll-like receptor-5 agonist for radiation-induced oral mucositis in beagle dogs.

This study aimed to evaluate the clinical safety and validate the radiomitigative effect of KMRC011, against radiation-induced oral mucositis in beagle dogs. Clinical safety was evaluated by assessing tolerability, complete blood tests, and plasma biochemistry after drug administration. The radiomitigative effect of KMRC011 was evaluated macropathologically and histopathologically after inducing oral mucositis iatrogenically using 20 Gy irradiation. The plasma concentration of interleukin-6 was measured via enzyme-linked immunosorbent assay, as a biomarker of KMRC011 bioreactivity. Decreased tolerability, increased neutrophil count, hepatic enzyme concentration, C-reactive protein concentration, and interleukin-6 concentration after the administration was observed and ceased within 24 h without additional treatment. Although all animals included in the present study developed severe mucositis in the late course of the study, animals administered KMRC011 showed less erythema, ulcer, inflammatory infiltration. These results suggest that KMRC011 may be used as an adjuvant for radiotherapy without severe adverse effects, especially during short-term radiotherapy, such as hypofractionated radiotherapy or stereotactic radiotherapy.

Efficacy of a Customized Three-Dimensional Printing Surgical Guide for Tibial Plateau Leveling Osteotomy: A Comparison With Conventional Tibial Plateau Leveling Osteotomy.

Objective: To prospectively evaluate the effect of a computed tomography (CT)-based three-dimensional (3D) printing surgical guide on surgical accuracy of tibial plateau leveling osteotomy (TPLO). Study Design: Cadaveric study. Animals: Canine cadaveric hindlimbs (n = 14). Methods: TPLO was performed on cadaver hindlimbs disarticulated at the coxofemoral joint to compare and evaluate the conventional TPLO method (n = 7) with one that used customized 3D printing surgical guides (n = 7). The operation time and postoperative tibial plateau angle (TPA) of the osteotomy were evaluated. Moreover, the osteotomy inclination, torsion, and distance and the direction of eccentricity were assessed using CT reconstruction. Results: Significant differences in the operation time (p < 0.001), postoperative TPA (p < 0.05), osteotomy inclination (p < 0.05), and osteotomy torsion (p < 0.05) were observed. Conclusion: The use of TPLO surgical guide reduced the operation time and inaccurate osteotomy. Clinical Significance: The surgical technique applied with a customized 3D printing surgical guide could be used to perform osteotomy and TPA adjustment more precisely than conventional TPLO.

Case Report: Multimodality Imaging of Infectious Sacroiliitis and Retroperitoneal Abscess Causing Hindlimb Ataxia in a Young Dog.

A 3-month-old intact male Labrador Retriever was presented for falling trauma and hindlimb ataxia. Radiography indicated radiolucent left sacroiliac joint with irregular margin. Computed tomography revealed thickened sublumbar muscles and hypoattenuated sacroiliac joint while magnetic resonance imaging demonstrated abscess at retroperitoneum and gluteal muscle. Ultrasonography showed lytic left sacroiliac joint with retroperitoneal fluid, and fine needle aspiration resulted Staphylococcus aureus. Hindlimb ataxia was attributed to infectious sacroiliitis and its secondary retroperitoneal abscess. As far as the authors' knowledge, this is the first report of multimodality imaging of infectious sacroiliitis with retroperitoneal abscess caused by S. aureus in a dog.

Deep-Learning-Based Automatic Segmentation of Head and Neck Organs for Radiation Therapy in Dogs.

Purpose: This study was conducted to develop a deep learning-based automatic segmentation (DLBAS) model of head and neck organs for radiotherapy (RT) in dogs, and to evaluate the feasibility for delineating the RT planning. Materials and Methods: The segmentation indicated that there were potentially 15 organs at risk (OARs) in the head and neck of dogs. Post-contrast computed tomography (CT) was performed in 90 dogs. The training and validation sets comprised 80 CT data sets, including 20 test sets. The accuracy of the segmentation was assessed using both the Dice similarity coefficient (DSC) and the Hausdorff distance (HD), and by referencing the expert contours as the ground truth. An additional 10 clinical test sets with relatively large displacement or deformation of organs were selected for verification in cancer patients. To evaluate the applicability in cancer patients, and the impact of expert intervention, three methods-HA, DLBAS, and the readjustment of the predicted data obtained via the DLBAS of the clinical test sets (HA_DLBAS)-were compared. Results: The DLBAS model (in the 20 test sets) showed reliable DSC and HD values; it also had a short contouring time of ~3 s. The average (mean ± standard deviation) DSC (0.83 ± 0.04) and HD (2.71 ± 1.01 mm) values were similar to those of previous human studies. The DLBAS was highly accurate and had no large displacement of head and neck organs. However, the DLBAS in the 10 clinical test sets showed lower DSC (0.78 ± 0.11) and higher HD (4.30 ± 3.69 mm) values than those of the test sets. The HA_DLBAS was comparable to both the HA (DSC: 0.85 ± 0.06 and HD: 2.74 ± 1.18 mm) and DLBAS presented better comparison metrics and decreased statistical deviations (DSC: 0.94 ± 0.03 and HD: 2.30 ± 0.41 mm). In addition, the contouring time of HA_DLBAS (30 min) was less than that of HA (80 min). Conclusion: In conclusion, HA_DLBAS method and the proposed DLBAS was highly consistent and robust in its performance. Thus, DLBAS has great potential as a single or supportive tool to the key process in RT planning.

Superiority of coarse eggshell as a calcium source over limestone, cockle shell, oyster shell, and fine eggshell in old laying hens.

Chicken eggshell (ES) waste is a rich source of calcium carbonate (CaCO3); however, the potential of ES as dietary calcium (Ca) in old laying hens has not been explored. This study compared the effects of feeding limestone, cockle shell, oyster shell, fine ES, and coarse ES as the sole Ca source on production performance, egg quality, blood biochemical constituents, and tibia characteristics in old laying hens. A total of 450 ISA-Brown laying hens at 73 wk of age with similar egg production rate (EPR) were randomly assigned to 5 treatment groups (90 hens/group, 9 hens/replicate) for 7 wk. Dietary treatment groups comprised a corn-soybean meal based diet containing different Ca sources: (i) limestone (LS; < 2 mm and 2-4 mm mixed in the ratio of 3:7) as control, (ii) cockle shell (CS; 1-4 mm), (iii) oyster shell (OS; 3-16 mm), (iv) ES fine particles (ESF; < 1 mm), and (v) ES coarse particles (ESC; 3-5 mm). Results indicated that dietary inclusion of coarse ES particles significantly increased average egg weight (P < 0.001) and daily egg mass (P < 0.05), and decreased feed conversion ratio (P < 0.001) as compared with the other treatments. However, no significant differences in EPR, feed intake, cracked egg proportion, and mortality were observed among the dietary treatments (P > 0.05). Notably, the use of ESF led to a lower proportion of cracked eggs than ESC (P < 0.05). ESC fed hens produced the heaviest eggs whereas CS fed hens produced the lightest (P < 0.001); the particle size of ES also affected the egg weight (P < 0.05). The eggs from OS and ESC fed hens showed a greater albumen height in comparison to eggs from CS group (P < 0.05); but no significant difference was observed among the LS, OS, ESF, and ESC groups (P > 0.05). The yolk color was darker in the eggs of group ESF as compared with other dietary groups (P < 0.01). However, no significant effects on Haugh units and shell properties were observed among the treatments (P > 0.05). The blood biochemistry results were not affected by the dietary Ca (P > 0.05) except for lower levels of high-density lipoprotein percentage (HDL %) in OS and ESC fed hens (P < 0.05). The tibia characteristics including weight, length, width, and breaking strength did not differ among the dietary groups (P > 0.05). However, the ESC and OS fed hens showed higher tibia bone mineral density (BMD) than the other groups (P < 0.001). In conclusion, coarse ES as a sole Ca source had beneficial effects on the production performance, egg quality, and tibia BMD in old laying hens.

Case Report: Multimodal Imaging Features of Pedunculated Liver Masses in Seven Dogs.

This study describes the multimodal imaging characteristics of pedunculated liver masses in seven dogs [Cocker Spaniel (n = 2), Maltese (n = 1), Shih-Tzu (n = 2), and Schnauzer (n = 2)]. These masses are anatomic variants of hepatic masses in which the center of the mass lies outside the liver contour. Prior to referral, only one dog had been diagnosed with a hepatic mass, four had been diagnosed with mid-abdominal masses of unknown origin, and two had been misdiagnosed with splenic head and pancreatic masses. Using radiographs, the mass locations were classified as cranioventral (n = 3), mid-abdominal (n = 2), or craniodorsal (n = 2). The gastric axis was deviated in various directions in four cases. Based on computed tomography (CT) findings, the masses were noted to originate from every liver lobe (two from the left lateral lobe) and to possess parenchymal (n = 6) or vascular (n = 1) pedicles. The histopathological results showed that three masses were benign [hepatic adenoma (n = 1) and nodular hyperplasia (n = 2)] and four were malignant [hepatocellular carcinoma (n = 3) and cholangiocarcinoma (n = 1)]. For three dogs, triple-phase CT maximum intensity projection images in the arterial phase clearly showed that the masses were connected to the hepatic artery. We propose that a pedunculated liver mass should be considered as a differential diagnosis when a mass is located in the mid-abdomen, even if it is separated from the liver and with the gastric axis deviated in various directions. We consider CT imaging to be a useful tool for diagnosis, evaluation, and surgical planning in dogs with a pedunculated liver mass.

Caudal vena cava aneurysm in a cat with Eisenmenger Syndrome.

A seven-month-old cat was referred for evaluation of exercise intolerance and open-mouth breathing. Based on ultrasonographic examination, caudal vena cava (CVC) aneurysm associated with right congestive heart failure resulting from congenital heart disease was diagnosed. Conservative treatment for alleviating pulmonary hypertension mildly improved the clinical signs and decreased the heart size and CVC aneurysm diameter. However, the improvements were transient and four months after initiating therapy, the cat developed dyspnea and uncontrollable seizures and was euthanized.