Differences in normal nasal computed tomography findings in different dog breeds.

Background: Computed tomography (CT) is the gold standard for diagnosing canine nasal diseases. However, it cannot easily detect minor abnormalities in inflammatory diseases because they are not accompanied by obvious morphological changes. Aim: The present study aimed to compare the differences in normal CT findings of turbinate structure and mucosa between breeds to establish criteria for CT diagnosis of inflammatory diseases of the nasal cavity. Methods: CT data from 77 dogs of 5 breeds without nasal diseases were retrospectively studied. The nasal air percentage, which reflects the volume of the nasal turbinate structure and mucosa, was measured. The nasal turbinate mucosa was measured for contrast enhancement reflecting blood flow. Measurements were performed in the ventral and ethmoid turbinate (ET) regions. Comparisons were made between breeds and sections. Results: The air percentage in the ventral and ET regions was significantly different between breeds. Contrast enhancement was significantly different between breeds only in the ET. Moreover, different breeds had different correlations between body weight, age, nose length, and air percentage. Conclusion: In this study, reference values for normal CT findings of the nasal structure and mucosa were obtained, taking into account the breed, measurement section, and patient factors. The results showed that the volume of the turbinate structure and contrast enhancement of nasal mucosa differed depending on the breed. The measured values also differed depending on the cross-sections and patient factors.

Quantitative evaluation of middle ear radiopacity in French bulldogs using X-ray imaging.

Background: Radiographic examination of the middle ear in French bulldogs can be challenging due to their small ear cavity and thick walls. Quantifying opacity on radiographic images is required to determine normal or abnormal results. Aim: To quantify the radiographic opacity of the middle ear in French bulldogs and create a threshold for objective diagnosis. Methods: A study was conducted on 32 French Bulldogs using radiographic images. Significant difference tests were performed on the ears of patients with unilateral and bilateral middle ear filling on computed tomography. A threshold was established for detecting left-right asymmetry in the same individuals. In addition, comparisons were made between the filling and nonfilling middle ear groups to establish a threshold of pixel values that could determine single middle ear filling and nonfilling for different patient images. Results: Significant differences were observed in the left-right difference in max, left-right difference in max-ave, and left-right ratio of max-ave between unilateral and bilateral filling groups. The max-ave left-right ratio had the highest area under the curve value with a cutoff of 1.077% and 92.3% sensitivity. The item that showed a significant difference between middle ear groups with and without filling was corrected for nasopharyngeal pixel values with a cutoff of 1.028% and 85% sensitivity. Conclusion: Pixel value ratios in the middle ear region can detect asymmetries in ear densities. The max value in the region compared to the same image's nasopharyngeal region can determine the filling. Combining individual ear evaluations and symmetry improves accuracy.

Effects of Neuromuscular Electrical Stimulation and Therapeutic Ultrasound on Quadriceps Contracture of Immobilized Rats.

Quadriceps contracture is a condition where the muscle-tendon unit is abnormally shortened. The treatment prognosis is guarded to poor depending on the progress of the disease. To improve the prognosis, we investigated the effectiveness of therapeutic ultrasound and NMES in treating quadriceps contracture in an immobilized rat model. Thirty-six Wistar rats were randomized into control, immobilization alone, immobilization and spontaneous recovery, immobilization and therapeutic ultrasound, immobilization and NMES, and immobilization and therapeutic ultrasound and NMES combination groups. The continuous therapeutic ultrasound (frequency, 3 MHz, intensity 1 W/cm2) and NMES (TENS mode, frequency 50 Hz; intensity 5.0 ± 0.8 mA) were performed on the quadriceps muscle. On Day 15, immobilization-induced quadriceps contracture resulted in a decreased ROM of the stifle joint, reduction in the sarcomere length, muscle atrophy, and muscle fibrosis. On Day 43, therapeutic ultrasound, NMES, and combining both methods improved muscle atrophy and shortening and decreased collagen type I and III and α-SMA protein. The combination of therapeutic ultrasound and NMES significantly reduced the mRNA expression of IL-1ß, TGF-ß1, and HIF-1α and increased TGF-ß3. Therefore, the combination of therapeutic ultrasound and NMES is the most potent rehabilitation program for treating quadriceps contracture.

Myogenic Differentiation and Immunomodulatory Properties of Rat Adipose-Derived Mesenchymal Stem/Stromal Cells.

The myogenic differentiation potential of MSCs is a key factor in their potential use as a cell source for muscle tissue repair and regeneration. Additionally, evaluating the immunomodulatory properties of MSCs is important to highlight their potential for regulating inflammation and supporting tissue regeneration. Given the limited literature on muscle differentiation potential and immunomodulatory properties, this study aims to characterize rat ADP MSCs for treating muscle disease. We isolated MSCs from adipose tissues around the periscapular region of the rats. We used a monoculture method for the myogenic differentiation and modified the myogenic induction medium by supplementing it with the growth factors FGF, HGF, and IGF. In rat ADP MSCs, expression of the MSC-specific marker, CD90, was 87.7%, while CD44 was 42.8%. For genes involved in immunomodulation, IGF1 and TGFB1 were highly expressed, while IL6 was poorly expressed. In addition to their trilineage differentiation potential, ADP MSCs exhibited the capacity to differentiate into myogenic cell lines, as evidenced by changes in cell morphology, leading to elongated and aligned structures and the expression of the MyoD and MYOG antibodies. The study found that ADP MSCs show great clinical promise for muscle regeneration.

Characterization of Rabbit Mesenchymal Stem/Stromal Cells after Cryopreservation.

Adipose tissues (ADPs) are an alternative source for mesenchymal stem/stromal cells (MSCs), given that conventional bone marrow (BM) collection is painful and yields limited cell numbers. As the need for easily accessible MSCs grows, cryopreservation's role in regenerative medicine is becoming increasingly vital. However, limited research exists on the characteristics and functional properties of rabbit-derived MSCs from various anatomical sources before and after cryopreservation. We examined the effects of cryopreservation using Bambanker. We found that cryopreservation did not adversely affect the morphology, viability, and adipogenic or chondrogenic differentiation abilities of ADP MSCs or BM MSCs. However, there was a notable drop in the proliferation rate and osteogenic differentiation capability of BM MSCs post-cryopreservation. Additionally, after cryopreservation, the surface marker gene expression of CD90 was not evident in ADP MSCs. As for markers, ADIPOQ can serve as an adipogenic marker for ADP MSCs. ACAN and CNMD can act as chondrogenic markers, but these two markers are not as effective post-cryopreservation on ADP MSCs, and osteogenic markers could not be validated. The study highlights that compared to BM MSCs, ADP MSCs retained a higher viability, proliferation rate, and differentiation potential after cryopreservation. As such, in clinical MSC use, we must consider changes in post-cryopreservation cell functions.

Cephalic and saphenous venous blood collected by continuous heating of the paws compared with arterial blood for measurement of blood gas values in well-perfused dogs.

BACKGROUND: "Arterialization" of the dorsal hand vein is well-established in human medicine, but not in veterinary medicine. OBJECTIVES: To compare cephalic and saphenous venous blood collected by continuously heating the paws to 37°C ("arterialization"), with arterial blood (AB) for measurement of blood gas variables in well-perfused dogs. ANIMALS: Eight healthy dogs. METHODS: Experimental study. Fore and hind paws were continuously heated to 37°C to "arterialize" cephalic and saphenous venous blood. AB and "arterialized" cephalic and saphenous venous blood (ACV and ASV, respectively) were simultaneously collected from lightly anesthetized dogs with induced metabolic and respiratory acid-base disorders. The pH, partial pressures of carbon dioxide (PCO2 ) and oxygen (PO2 ), bicarbonate concentration [HCO3 - ], and base excess (BE) were measured once in each state. Systolic blood pressure was maintained above 100 mm Hg. The AB, ACV, and ASV values were compared. RESULTS: The pH, [HCO3 - ], and BE values had no significant difference and good agreement, the PCO2 values had a strong correlation (correlation coefficient of .91-1.00), and the PO2 values had a significant difference (P < .01) and poor agreement between AB and ACV, and between AB and ASV. The PCO2 values of ASV overestimated those of AB by ~3.0 mm Hg, which was considered within clinically allowable limits, while those of ACV were not within clinically allowable limits. CONCLUSIONS AND CLINICAL IMPORTANCE: Under experimental conditions, the ASV samples were more identical to the AB samples than the ACV samples for pH, PCO2 , [HCO3 - ], and BE values in well-perfused dogs. The saphenous vein is suitable for "arterialization."

Usefulness of Ultrasound Shear Wave Elastography for Detection of Quadriceps Contracture in Immobilized Rats.

Quadriceps contracture is an abnormal pathological shortening of the muscle-tendon unit. To improve the prognosis of quadriceps contracture, improvement of its diagnostic method is needed. In this study, we evaluated the diagnostic utility of ultrasound shear wave elastography in a rat model of quadriceps contracture induced by immobilization. Fifty Wistar rats were randomly divided into control and immobilization groups. During up to 4 weeks of joint immobilization, the quadriceps elastic modulus, muscle hardness, creatinine phosphokinase levels, joint range of motion, histopathologic parameters, and levels of fibrosis-associated mRNA expression were measured every week in the immobilization and control groups and compared. In the immobilization group, the elastic modulus gradually but significantly increased (p < 0.05) throughout the immobilization period. However, muscle hardness and serum creatinine phosphokinase levels only increased at 1 and 2 weeks after the start of immobilization, respectively. Muscle atrophy and shortening progressed throughout the immobilization group. Collagen type I and III, α-SMA protein, and mRNA expression of IL-1ß and TGF-ß1 significantly increased (p < 0.05) throughout in the immobilization group. Ultrasound shear wave elastography is the most useful method for clinical assessment of muscle contracture.

Rat Model of Quadriceps Contracture by Joint Immobilization.

Muscle contracture is an abnormal pathologic process resulting in fibrosis and muscle atrophy, which can lead to limitation of joint motion. To establish a diagnostic method to detect muscle contracture and a method to control its progression, we investigated an appropriate method to create an animal model of quadriceps contracture using rats. Eighteen Wistar rats were divided into three groups, and bilateral hindlimbs were immobilized with either a cast (Group I), a Velcro hook-and-loop fastener (Group V), or steel wire (Group S) with the knee and ankle joints in extension position for two weeks. Five rats in a control group (Group C) were not immobilized. After two weeks, the progression of quadriceps contracture was assessed by measuring the range of joint motion and pathohistological changes. Muscle atrophy and fibrosis were observed in all immobilization groups. The knee joint range of motion, quadriceps muscle weight, and muscle fiber size decreased only in Group S compared to the other immobilization groups. Stress on rats due to immobilization was less in Group S. These results indicate that Group S is the superior quadriceps contracture model. This model aids research investigating diagnostic and therapeutic methods for muscle contracture in humans and animals.

An elevation transect study of testate amoeba communities up to 4000 m a.s.l. on Mount Kinabalu, Borneo.

Testate amoebae are a polyphyletic assemblage of unicellular eukaryotes with a specific shell. They occur frequently in soil and freshwater habitats all over the world, important for ecosystem functioning and useful for bio-indication. Terrestrial amoeba data from Borneo or Malaysia are rarely available. In this study, data on species composition and relative abundance were presented along a transect from 1730 m up to 4000 m above sea level from 10 elevational levels on Mt. Kinabalu, Malaysian Borneo. In total 78 morphotypes of testate amoebae were recorded. Most were small (under 100 µm) and supposedly cosmopolitan. However, Certesella certesi with limited geographical distribution and some rare taxa (e.g., Padaungiella lageniformis cordiformis, Placocista jurassica, Trinema chardezi) and two undescribed morphospecies were also observed. Presence/absence and relative abundance data of testate amoebae were associated to elevation with a pronounced change at the tree line, as revealed by non-metric multidimensional scaling ordination analysis. Our data from Southeast Asia contribute to the actual discussion on distributional patterns considering elevation gradients and biogeography of eukaryotic microbes.

Evaluation of cerebral blood flow in the hippocampus, thalamus, and basal ganglia and the volume of the hippocampus in dogs before and during treatment with prednisolone.

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.

Age-related change in shear elastic modulus of the thoracolumbar multifidus muscle in healthy Beagle dogs using ultrasound shear wave elastography.

BACKGROUND: Multifidus muscle stiffness decreases in patients with lumbar intervertebral disk herniation; however, age-related changes in humans have not been reported. OBJECTIVES: The reliability of ultrasound shear wave elastography in dogs, and changes in the shear elastic modulus of the thoracolumbar multifidus muscle with aging in dogs, were investigated. METHODS: Twelve beagle dogs were divided into 2 groups based on the age of onset of intervertebral disk herniation: young (aged not exceeding 2 years; 1.3 ± 0.6 years old, n = 5) and adult (4.9 ± 1.2 years old, n = 7). The shear elastic modulus of the multifidus muscle, from the thirteenth thoracic spine to the fourth lumbar spine, was measured using ultrasound shear wave elastography. The length, cross-sectional area and muscle to fat ratio of the multifidus muscle, and the grade of intervertebral disk degeneration, were assessed using radiographic and magnetic resonance imaging examinations. RESULTS: The length and cross-sectional area of the multifidus muscle increased caudally. In the young group, the shear elastic modulus of the multifidus muscle of the thirteenth thoracic spine was less than that of the third lumbar spine. In the adult group, the shear elastic modulus of the multifidus muscle of first and third lumbar spine was lower than that of the same site in the young group. CONCLUSIONS: Ultrasound can be used to measure shear wave elastography of the thoracolumbar multifidus in dogs. If the multifidus muscle stiffness decreases, we should consider age-related change.

Dlx5-augmentation in neural crest cells reveals early development and differentiation potential of mouse apical head mesenchyme.

Neural crest cells (NCCs) give rise to various tissues including neurons, pigment cells, bone and cartilage in the head. Distal-less homeobox 5 (Dlx5) is involved in both jaw patterning and differentiation of NCC-derivatives. In this study, we investigated the differentiation potential of head mesenchyme by forcing Dlx5 to be expressed in mouse NCC (NCCDlx5). In NCCDlx5 mice, differentiation of dermis and pigment cells were enhanced with ectopic cartilage (ec) and heterotopic bone (hb) in different layers at the cranial vertex. The ec and hb were derived from the early migrating mesenchyme (EMM), the non-skeletogenic cell population located above skeletogenic supraorbital mesenchyme (SOM). The ec developed within Foxc1+-dura mater with increased PDGFRα signalling, and the hb formed with upregulation of BMP and WNT/ß-catenin signallings in Dermo1+-dermal layer from E11.5. Since dermal cells express Runx2 and Msx2 in the control, osteogenic potential in dermal cells seemed to be inhibited by an anti-osteogenic function of Msx2 in normal context. We propose that, after the non-skeletogenic commitment, the EMM is divided into dermis and meninges by E11.5 in normal development. Two distinct responses of the EMM, chondrogenesis and osteogenesis, to Dlx5-augmentation in the NCCDlx5 strongly support this idea.

Correction to: Very long chain fatty acids are an important marker of nutritional status in patients with anorexia nervosa: a case control study.

[This corrects the article DOI: 10.1186/s13030-020-00186-8.].

Very long chain fatty acids are an important marker of nutritional status in patients with anorexia nervosa: a case control study.

BACKGROUND: Anorexia nervosa (AN) is a disease resulting in extreme weight loss. It is caused by multiple factors, including psychosocial, environmental, and genetic factors. A genetic abnormality affecting lipid metabolism has been recently reported in patients with AN. However, it is unknown whether lipid metabolism abnormalities in AN are caused by eating behavior, undernutrition, and/or genetic factors. The meaning of lipid metabolism in AN remains unclear. In particular, differences in the profiles of very long-chain fatty acids (VLCFAs) in patients with various types of AN have not been studied. This study aimed to determine changes to the fatty acid profile over a 3-month period, specifically that of long-chain fatty acids (LCFAs) and VLCFAs in patients with various types of AN. METHODS: We evaluated 69 female patients with AN, subclassified as AN-restricting type (AN-R) and AN-Binge-Eating/Purging type (AN-BP). On admission and after 3 months of treatment, height, weight, body mass index, plasma and serum parameters, and plasma fatty acid concentrations were measured in all patients. The control group included 25 healthy, age-matched women. Comparisons between the groups were made using one-way ANOVA, while those between the various parameters at admission and after 3 months within each group were made using the Wilcoxon signed rank test. RESULTS: On admission, the AN-R and the AN-BP groups had significantly higher levels of 18-24C and > 14C fatty acids (LCFAs and VLCFAs, respectively) than the control group. After 3 months of treatment, both groups showed high levels of 14-24C fatty acids. The levels of VLCFAs (C22:0 and C24:0) and LCFA (C18:3) after 3 months of treatment remained high in both AN groups relative to the control group. CONCLUSIONS: Eating behaviors appear to be associated with levels of LCFAs. Lipid metabolism abnormalities under conditions of starvation in AN might have a genetic basis and appear to be associated with VLCFA (C22:0 and C24:0) and LCFA (C18:3) levels.

Soil Testate Amoebae and Diatoms as Bioindicators of an Old Heavy Metal Contaminated Floodplain in Japan.

Soil protists are rarely included in ecotoxicological investigations, despite their fundamental role in ecological processes. Moreover, testate amoebae and diatoms contribute considerably to silicon fluxes in soils. We investigated the effects of heavy metals on testate amoebae (species and individual densities) and diatoms (individual densities) in aged soils of a floodplain (Watarase retarding basin, Japan) taking soil samples from two unpolluted reference sites and two polluted sites. The total concentrations of Cu, Pb, and Zn in soil were higher at the polluted sites as compared with the reference sites. The available concentrations of Co, Cu, and Zn in CaCl2 extracts were higher at the polluted sites but available Pb was not detectable. Testate amoeba taxonomic richness was higher in the reference sites (45/38 taxa) than in the polluted sites (36/27 taxa). The reference sites had higher diatom and amoeba densities than the polluted sites. There was a significant negative correlation between total testate amoeba density and heavy metal concentration (available Co), while significant negative correlations were found between diatom density and Co, Cu, and Zn (available and total concentration). Densities of Cyclopyxis kahli cyclostoma, Centropyxis spp., and Trinema complanatum were negatively correlated to concentrations of available heavy metals. The observed decrease in individual numbers due to heavy metal pollution resulted in a considerable decline in protozoic (testate amoebae) and protophytic (pennate diatoms) silicon pools. Our data suggest that heavy metal pollution affects biogeochemical cycling in this system.

Change in Shear Elastic Modulus of Thigh Muscle by Changing Muscle Length Using Ultrasound Shear Wave Elastography in Beagle Dogs.

OBJECTIVES: This study investigated the relationship between the change in the shear elastic modulus and the change in muscle length using ultrasound shear wave elastography. STUDY DESIGN: Four thigh muscles, cranial part of the sartorius, vastus lateralis, biceps femoris and semitendinosus muscles, of 21 pelvic limbs in 12 clinically healthy Beagle dogs were used. The muscle length was estimated using a radiograph and the flexed and extended positions of the coxofemoral and stifle joints, respectively. The shear elastic modulus (kPa) was measured in two joint positions using ultrasound shear wave elastography. Shear elastic modulus was expressed as median of 10 consecutive measurements. The percentage change of elastic modulus was calculated from the shear elastic modulus in elongated condition and pre-elongated condition of muscle. RESULTS: The elastic modulus of all muscles increased when the muscle was elongated. The shear elastic modulus for both joint positions and the percentage change of the shear elastic modulus (%) in cranial part of the sartorius were highest in all muscles. Intra-observer correlation coefficient (1.2) was 0.75 to 0.96 and intra-observer correlation coefficients (2.2) was 0.46 to 0.96. CONCLUSION: This study revealed that the shear elastic modulus of muscle was changed by the change in muscle length and increased when the muscle was elongated. Ultrasound shear wave elastography can be used to assess the elastic properties of canine muscle.

Inotropic and lusitropic effects of incremental doses of dobutamine in dogs with right ventricular apical pacing-induced cardiac dysfunction.

This study aimed to assess the effects of incremental doses of dobutamine on diastolic function in healthy and rapid ventricular apical pacing (RVAP)-induced cardiac dysfunction anesthetized dogs. Inotropic and lusitropic effects of dobutamine (2, 4, 8, and 12 µg kg-1  min-1 ) were assessed through left ventricle (LV) pressure-volume relation and Doppler echocardiography in six female dogs before and after 8 weeks of RVAP. Peak rate of LV pressure fall (-dP/dtmin ) improved with doses >4 µg kg-1  min-1 in healthy (4,490 ± 970 vs. 3,265 ± 471 mmHg/s, p < 0.05) and >8 µg kg-1  min-1 in RVAP dogs (3,385 ± 1,122 vs. 1,864 ± 849 mmHg/s, p < 0.05) while the time constant of relaxation (tau) reduced with doses >4 µg kg-1  min-1 in both groups (healthy: 24.0 ± 3.7 vs. 28.2 ± 4.9 ms; RVAP: 32.6 ± 8.5 vs. 37.5 ± 11.4 ms, p < 0.05) comparing with baseline. Indices of relaxation (-dP/dtmin and tau) suggested preserved lusitropic response in contrast with markedly reduced indices of contractility in the RVAP group compared with healthy group at same infusion rates. Doppler echocardiography showed significant reduction of elastic recoil in failing hearts. The results of this study demonstrated maximal positive lusitropic effects of dobutamine at a dose of 8 µg kg-1  min-1 in ventricular pacing-induced cardiac dysfunction without further impairment of ventricular filling.

Probing the origin of matching functional jaws: roles of Dlx5/6 in cranial neural crest cells.

Gnathostome jaws derive from the first pharyngeal arch (PA1), a complex structure constituted by Neural Crest Cells (NCCs), mesodermal, ectodermal and endodermal cells. Here, to determine the regionalized morphogenetic impact of Dlx5/6 expression, we specifically target their inactivation or overexpression to NCCs. NCC-specific Dlx5/6 inactivation (NCC∆Dlx5/6) generates severely hypomorphic lower jaws that present typical maxillary traits. Therefore, differently from Dlx5/6 null-embryos, the upper and the lower jaws of NCC∆Dlx5/6 mice present a different size. Reciprocally, forced Dlx5 expression in maxillary NCCs provokes the appearance of distinct mandibular characters in the upper jaw. We conclude that: (1) Dlx5/6 activation in NCCs invariably determines lower jaw identity; (2) the morphogenetic processes that generate functional matching jaws depend on the harmonization of Dlx5/6 expression in NCCs and in distinct ectodermal territories. The co-evolution of synergistic opposing jaws requires the coordination of distinct regulatory pathways involving the same transcription factors in distant embryonic territories.

Assessment of T2 Relaxation Times for Normal Canine Knee Articular Cartilage by T2 Mapping Using 1.5-T Magnetic Resonance Imaging.

Objectives This study aims to assess and compare the T2 relaxation times for articular cartilage of normal canine stifle joints in four regions by T2 mapping using a 1.5-T magnetic resonance imaging (MRI). Methods In vivo prospective study: 20 hindlimbs (left and right) from 10 normal healthy beagle dogs (n = 20). The region of interest (ROI) was subdivided into medial and lateral condyles of femoral cartilage (MF and LF, respectively) and medial and lateral condyles of tibial cartilage (MT and LT, respectively). The T2 relaxation times were assessed in regions where the cartilage thickness was greater than 0.5 mm. Results The median maximum cartilage thickness (mm) of the four ROI were 0.7 (range: 0.9-0.6), 0.6 (range: 0.7-0.5), 0.7 (range: 0.9-0.5) and 0.6 (range: 0.8-0.5) at MF, LF, MT and LT, respectively. The errors in the measurement (%) of the four ROI were 64.3 (range: 50.0-75.0), 75.0 (range: 64.3-90.0), 64.3 (range: 20.0-90.0) and 75.0 (range: 56.3-90.0) at MF, LF, MT and LT, respectively. The median T2 relaxation times (ms) for the articular cartilage of the four ROI were 70.2 (range: 57.9-87.9), 57.5 (range: 46.8-66.9), 65.0 (range: 52.0-92.0) and 57.0 (range: 49.0-66.2) at MF, LF, MT and LT, respectively. The inter-observer correlation coefficient (ICC, 2.1) for the T2 relaxation times of MF was 0.644. Clinical Significance This study offers useful information on T2 relaxation times for articular cartilage of the stifle joint using a 1.5-T MRI in normal dogs.

Ultrasound-guided femoral nerve block using a ventral suprainguinal approach in healthy dogs.

OBJECTIVE: To determine whether an ultrasound (US)-guided femoral nerve block using a ventral suprainguinal approach could be successfully achieved in sedated dogs; to measure the time to execute the nerve block, onset time, duration, and complete block rate in sensory and motor nerves; and to examine any differences between two volumes for injection. STUDY DESIGN: Blinded crossover experimental study. ANIMALS: A total of 10 clinically healthy adult Beagle dogs. METHODS: The femoral nerve of the right pelvic limb was infiltrated with 0.5% bupivacaine at 0.4 (treatment 0.4B) or 0.2 mL kg-1 (treatment 0.2B), or saline at 0.4 mL kg-1 (control) in sedated dogs. The sensory and motor nerve functions were scored on a scale of 0 (complete blockade) to 2 (normal). The onset time and duration of the sensory and motor nerve blockade were compared between treatments 0.4B and 0.2B using a Wilcoxon signed rank test. Sensory and motor nerve function scores for each of the three treatments were compared at multiple time points using a nonparametric multiple comparisons test. RESULTS: The time to execute the nerve block was 2.5 ± 0.9 minutes (n = 30). For both 0.4B and 0.2B treatments, the onset times of both the sensory and motor nerve blockades were 15 minutes. The durations of the sensory nerve blockade for 0.4B and 0.2B were 9.9 ± 1.4 and 10.0 ± 1.2 hours, respectively, and those of the motor nerve blockades were 10.5 ± 1.3 and 10.2 ± 1.3 hours, respectively. No adverse effects were noted. No significant difference was observed between 0.4B and 0.2B. CONCLUSIONS AND CLINICAL RELEVANCE: A US-guided femoral nerve block using a ventral suprainguinal approach demonstrated a short onset and long duration with 0.5% bupivacaine 0.2 mL kg-1 and can be performed under sedation in dogs.