Introduction: The aim of the study was to analyse selected densitometric and geometric parameters in the third metacarpal bone along the long axis in horses. The densitometric parameters included the cortical and trabecular bone mineral density, while the geometric parameters included the cortical, trabecular, and total areas, strength strain index X, strength strain index Y, and the polar strength strain index. Material and Methods: The parameters were analysed using eight sections from 10% to 80% of the length of the bone. Peripheral quantitative computed tomography was used in the study. Statistical analysis was carried out using the Friedman analysis of variance and post-hoc tests. Results: The proximal metaphyseal region showed the highest predicted resistance to bone fractures in the transverse (back-front) plane, the distal metaphyseal region had the highest predicted resistance to transverse and torsional fractures in the transverse (side-side) plane. The cross-sectional area and the shape of the cross-section of the cortical bone of the MCIII had the highest coefficient of variation. The density of the cortical bone was least variable. Conclusions: The cortical area and cortical bone mineral density assumed the highest values in the diaphyseal region, while the highest total area, trabecular area and trabecular bone mineral density values were obtained in the metaphyseal proximal and distal region.

OBJECTIVE To describe methods to measure the 3-D orientation of the proximal, diaphyseal, and distal segments of the canine radius by use of computer-aided design software (CADS) and to compare the repeatability and reliability of measurements derived by those methods. SAMPLE 31 canine radii with biapical deformities and 24 clinically normal (control) canine radii. PROCEDURES Select CT scans of radii were imported into a CADS program. Cartesian coordinate systems for the humerus and proximal, diaphyseal, and distal radial segments were developed. The orientation of each radial segment in the frontal, sagittal, and transverse planes was measured in triplicate by 3 methods. The repeatability and reliability of those measurements were calculated and compared among the 3 measurement methods. RESULTS The mean ± SD within-subject repeatability of radial angular measurements for all 3 methods was 1.40 ± 0.67° in the frontal plane, 3.17 ± 2.21° in the sagittal plane, and 3.01 ± 1.11° in the transverse plane for control radii and 2.56 ± 1.95° in the frontal plane, 3.59 ± 2.39° in the sagittal plane, and 3.47 ± 1.19° in the transverse plane for abnormal radii. Mean ± SD bias between radial measurement methods was 1.88 ± 2.07° in the frontal plane, 6.44 ± 6.80° in the sagittal plane, and 2.27 ± 2.81° in the transverse plane. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that use of CADS to assess the 3-D orientation of the proximal, diaphyseal, and distal segments of normal and abnormal canine radii yielded highly repeatable and reliable measurements.

OBJECTIVE To evaluate the 3-D geometry of canine pelves and to characterize the long-term effects of juvenile pubic symphysiodesis (JPS) on pelvic geometry by comparing the pelvic configuration between littermates that did and did not undergo the procedure. ANIMALS 24 Labrador Retriever, Golden Retriever, or Labrador Retriever–Golden Retriever crossbred service dogs from 13 litters. PROCEDURES At 16 weeks old, puppies with a hip joint distraction index ≥ 0.5 were randomly assigned to undergo thermal JPS (n = 9), mechanical JPS (7), or a sham (control) surgical procedure (8). Ten years later, each dog underwent a CT scan of the pelvic region. Modeling software was used to create 3-D reconstructions from the CT scans, and various pelvic measurements were made and compared among the 3 treatments. RESULTS Compared with the control treatment, thermal and mechanical JPS increased the hemipelvis acetabular angle by 4°, the acetabular angle of lateral opening by 5°, and the orientation of the medial acetabular wall in a transverse plane by 6°, which indicated that JPS increased dorsal femoral head coverage by the acetabulum. Both JPS procedures decreased the pelvic canal area by approximately 20% and acetabular inclination by 6° but did not alter acetabular retroversion. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that thermal and mechanical JPS were equally effective in altering the 3-D pelvic geometry of dogs. These findings may help guide future studies of alternatives for optimizing canine pelvic anatomy to minimize the risk of hip dysplasia and associated osteoarthritis.

OBJECTIVE To evaluate pharmacokinetic and pharmacodynamic characteristics of 3 doses of tapentadol hydrochloride orally administered in dogs. ANIMALS 6 healthy adult mixed-breed dogs. PROCEDURES In a prospective, randomized crossover study, dogs were assigned to receive each of 3 doses of tapentadol (10, 20, and 30 mg/kg, PO); there was a 1-week washout period between subsequent administrations. Plasma concentrations and physiologic variables were measured for 24 hours. Samples were analyzed by use of high-performance liquid chromatography–tandem mass spectrometry. RESULTS Tapentadol was rapidly absorbed after oral administration. Mean maximum plasma concentrations after 10, 20, and 30 mg/kg were 10.2, 19.7, and 31 ng/mL, respectively. Geometric mean plasma half-life of the terminal phase after tapentadol administration at 10, 20, and 30 mg/kg was 3.5 hours (range, 2.7 to 4.5 hours), 3.7 hours (range, 3.1 to 4.0 hours), and 3.7 hours (range, 2.8 to 6.5 hours), respectively. Tapentadol and its 3 quantified metabolites (tapentadol sulfate, tapentadol-O-glucuronide, and desmethyltapentadol) were detected in all dogs and constituted 0.16%, 2.8%, 97%, and 0.04% of the total area under the concentration-time curve (AUC), respectively. Plasma AUCs for tapentadol, tapentadol sulfate, and tapentadol-O-glucuronide increased in a dose-dependent manner. Desmethyltapentadol AUC did not increase in a linear manner at the 30-mg/kg dose. Sedation scores and heart and respiratory rates were not significantly affected by dose or time after administration. CONCLUSIONS AND CLINICAL RELEVANCE Oral administration of tapentadol was tolerated well, and the drug was rapidly absorbed. Adverse events were not apparent in any dogs at any doses in this study.

OBJECTIVE To evaluate accuracy of articular surfaces determined by use of 2 perpendicular CT orientations, micro-CT, and laser scanning. SAMPLE 23 cat cadavers. PROCEDURES Images of antebrachia were obtained by use of CT (voxel size, 0.6 mm) in longitudinal orientation (CTLO images) and transverse orientation (CTTO images) and by use of micro-CT (voxel size, 0.024 mm) in a longitudinal orientation. Images were reconstructed. Craniocaudal and mediolateral length, radius of curvature, and deviation of the articular surface of the distal portion of the radius of 3-D renderings for CTLO, CTTO, and micro-CT images were compared with results of 3-D renderings acquired with a laser scanner (resolution, 0.025 mm). RESULTS Measurement of CTLO and CTTO images overestimated craniocaudal and mediolateral length of the articular surface by 4% to 10%. Measurement of micro-CT images underestimated craniocaudal and mediolateral length by 1%. Measurement of CTLO and CTTO images underestimated mediolateral radius of curvature by 15% and overestimated craniocaudal radius of curvature by > 100%; use of micro-CT images underestimated them by 3% and 5%, respectively. Mean ± SD surface deviation was 0.26 ± 0.09 mm for CTLO images, 0.30 ± 0.28 mm for CTTO images, and 0.04 ± 0.02 mm for micro-CT images. CONCLUSIONS AND CLINICAL RELEVANCE Articular surface models derived from CT images had dimensional errors that approximately matched the voxel size. Thus, CT cannot be used to plan conforming arthroplasties in small joints and could lack precision when used to plan the correction of a limb deformity or repair of a fracture.

Conventional geometric formulas for estimating bladder volume assume that bladders have a perfectly uniform spheroid geometry. Bladders are often irregularly shaped, however, especially when under-filled or distorted by a full colon, which results in inaccurate ultrasonographic linear measurements and volume estimation. This pilot study investigates the feasibility, inter-observer reliability (reproducibility), robustness, and agreement of a novel 3-dimensional bladder volume computation method using bladder circumference tracing compared to a published feline linear bladder dimension formula. Paired sets of longitudinal and transverse B-mode bladder ultrasound images (n = 228) were acquired by 2 observers with different point-of-care ultrasonography skills using 10 healthy purpose-bred cats positioned in dorsal recumbency at various time points. Using strict criteria for Lin's concordance correlation coefficient, inter-observer agreements (n = 223) were found to be substantial (0.95 to 0.99) with statistically significant but clinically non-significant median differences (biases) of 0.96 mL [interquartile range (IQR): 0.16 to 2.46, P < 0.001] and 0.23 mL (IQR: 0.88 to 1.97, P = 0.006) when bladder circumference tracings were made on similar sets of ultrasound images respectively. Inter-observer agreements improved from substantial (0.95 to 0.99) to almost perfect (> 0.99) strength-of-agreement as the quality of ultrasound images improved. The bladder circumference tracing method showed moderate (0.90 to 0.95) strength-of-agreement with the recently published feline linear bladder dimension formula, with significant additive median differences (biases) of -6.76 mL (IQR: -9.06 to -3.88, P < 0.001) and -6.44 mL (IQR: -11.41 to -3.81, P < 0.001) recorded by each observer (n = 111, n = 83), respectively. Data obtained from orthogonal ultrasonographic bladder circumference tracings justify further investigation into use of this method for estimating bladder volume in cats.

OBJECTIVE To determine titers of serum antibodies against 3 genotypes of bovine parainfluenza 3 virus (BPI3V) in unvaccinated ungulates in Alabama. ANIMALS 62 cattle, goats, and New World camelids from 5 distinct herds and 21 captured white-tailed deer. PROCEDURES Serum samples were obtained from all animals for determination of anti-BPI3V antibody titers, which were measured by virus neutralization assays that used indicator (reference) viruses from each of the 3 BPI3V genotypes (BPI3V-A, BPI3V-B, and BPI3V-C). The reference strains were recent clinical isolates from US cattle. Each sample was assayed in triplicate for each genotype. Animals with a mean antibody titer = 2 for a particular genotype were considered seronegative for that genotype. RESULTS Animals seropositive for antibodies against BPI3V were identified in 2 of 3 groups of cattle and the group of New World camelids. The geometric mean antibody titer against BPI3V-B was significantly greater than that for BPI3V-A and BPI3V-C in all 3 groups. All goats, captive white-tailed deer, and cattle in the third cattle group were seronegative for all 3 genotypes of the virus. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that BPI3V-A may no longer be the predominant genotype circulating among ungulates in Alabama. This may be clinically relevant because BPI3V is frequently involved in the pathogenesis of bovine respiratory disease complex, current vaccines contain antigens against BPI3V-A only, and the extent of cross-protection among antibodies against the various BPI3V genotypes is unknown.