American journal of veterinary research最新文献

Objective: To evaluate the pharmacokinetics of emodepside in dogs following single-dose administration of the FDA-approved feline topical solution orally and topically and the European Medicines Agency-approved canine modified-release tablet orally and to assess the bioequivalence of the feline topical solution administered orally compared to the canine modified-release tablet.

Methods: This study was conducted in 3 phases, during which dogs received single doses of emodepside as the feline topical solution (1 mg/kg) orally, the canine modified-release tablet (1 mg/kg) orally, and the topical feline solution (3 mg/kg) topically. Plasma pharmacokinetic profiles were determined for 21 days postdose. Bioequivalence testing was conducted for orally administered emodepside.

Results: 7 healthy client-owned dogs (4 female and 3 male) were prospectively enrolled in this crossover study from May through August 2023. Oral administration of the feline topical solution resulted in markedly greater emodepside absorption than the modified-release tablet and was not bioequivalent. Emodepside plasma concentrations following topical administration of the FDA formulation were 36- to 122-fold lower than after oral administration.

Conclusions: The feline topical solution administered orally at 1 mg/kg is not bioequivalent to the canine modified-release tablet. Markedly higher absorption of the feline topical solution administered orally raises potential safety concerns for extralabel use in dogs to treat multianthelmintic drug-resistant hookworm infections. Poor absorption following topical administration suggests it may be unsuitable for treating multianthelmintic drug-resistant hookworm infections.

Clinical relevance: These findings highlight potential emodepside toxicity risks with extralabel use of the FDA-approved topical feline product and help inform safe off-label use in dogs.

Objective: To determine pharmacokinetic parameters after IV and SC administration of a single dose of maropitant.

Methods: In this experimental study, adult orange-winged Amazon parrots were administered a single dose of maropitant (1 mg/kg) SC and IV with an 8-week washout period between experiments. Blood samples were collected at 0.5, 1.5, 2, 3, 6, 9, 12, and 24 hours after drug administration for the SC study. For the IV study, samples were taken at the same time points with additional collections at 5 minutes and 36 hours. Plasma maropitant was determined with LC-MS-MS, and pharmacokinetic parameters were calculated using a noncompartmental model.

Results: A total of 8 orange-winged Amazon parrots (2 female and 6 male) were used in this study. Mean ± SD maximum concentration after SC administration was 130.9 ± 24.6 ng/mL and was reached at 0.5 ± 0 hours. Combined terminal half-life after SC administration was 6.67 hours. Bioavailability after SC administration was 85%. Plasma concentration at 24 hours was negligible and nearly identical between SC and IV administrations.

Conclusions: A single dose of 1 mg/kg was well tolerated in all birds IV and SC. Maropitant rapidly attained plasma concentrations following SC administration and had a relatively high bioavailability and short half-life.

Clinical relevance: The results of this study suggest that the currently used doses and dosing intervals for maropitant in psittacine birds do not maintain above-target plasma concentrations considered therapeutic in dogs and may be insufficient to achieve systemic effects comparable to those observed in other species.

Objective: To compare the sedative effects of intranasal (IN) alfaxalone to IM alfaxalone with or without IM midazolam in cockatiels (Nymphicus hollandicus).

Methods: A prospective, blinded, crossover study was performed on 8 healthy male cockatiels from February through April 2021. Birds randomly received 4 treatments with at least a 1-week washout period: alfaxalone at 15 mg/kg, IN (IN-A); alfaxalone at 15 mg/kg, IM, with (IM-AM) or without (IM-A) midazolam at 3 mg/kg, IM; and midazolam at 3 mg/kg, IM (IM-M). Time to recumbency and heart and respiratory rates were recorded. Ten minutes following administration, birds were restrained for sham 2-view radiographs and venipuncture. Following venipuncture, flumazenil at 0.1 mg/kg, IM, was administered (IM-AM and IM-M). Time to standing was recorded. Data were analyzed using a linear mixed model, a mixed effects γ-regression model, and Cochran Q, Friedman, and Wilcoxon signed-rank tests.

Results: No sedative effects were observed in IN-A. Recumbency was achieved in 0/8, 5/8, 8/8, and 0/8 birds in IN-A, IM-A, IM-AM, and IM-M, respectively. Respiratory and heart rates remained within acceptable limits in all birds. Sham radiographs were acquired in 0/8, 1/8, 6/8, and 0/8 birds in IN-A, IM-A, IM-AM, and IM-M, respectively. Venipuncture was successful in all birds with median lactate concentrations of 4.9, 2.4, 1.0, and 1.8 mmol/L in IN-A, IM-A, IM-AM, and IM-M, respectively. Median (range) time to standing after handling in IM-A and IM-AM was 8.8 (0 to 15.0) and 14.5 (0.6 to 15.5) min, respectively.

Conclusions: Intranasal alfaxalone at 15 mg/kg did not produce sedation.

Clinical relevance: Intramuscular alfaxalone at 15 mg/kg with midazolam at 3 mg/kg produced sedation in cockatiels.

Objective: To experimentally compare the diameter, maximal tension, number of twists, and slope of tension prior to failure for 18-gauge orthopedic wire from 3 vendors.

Methods: On November 22, 2024, 25 samples of 18-gauge orthopedic wire were each cut from spools of 3 different commercially available orthopedic wire brands (group A, IMEX; group B, VOI; group C, JORVET). Each sample's diameter was measured with a digital micrometer. Wires were secured with a twist knot around a simulated bone model attached to a digital load cell. Tension was recorded with each full twist until the wire broke. Maximum tension and number of twists prior to failure were recorded. Analysis of variance and Kruskal-Wallis tests were used for comparative analyses.

Results: Wire diameter (SD [mm]) was statistically smaller in group A (0.99 [0.01]) than in groups B (1.19 [0.01]) and C (1.2 [0.01]), and group C was statistically larger than B. Mean (SD) maximum tension was lower in group A (191.6 N [37.3]) than groups B (271.9 N [41.3]) or C (288.4 N [42.2]) but not statistically different between groups B and C.

Conclusions: Metrics of orthopedic wire gauge were not standardized across all suppliers. Smaller-diameter wire had a lower maximum tension but greater ductility and withstood more twists prior to wire breakage than larger-diameter wire.

Clinical relevance: Wire gauge is a flawed metric when specifying or describing wire size and subsequent mechanical behavior. Future clinical and research publications should specify wire gauge and wire diameter to promote accuracy due to the lack of standardization.

Objective: To determine normal reference ranges for end-inspiratory and end-expiratory planimetric cardiothoracic ratios in apparently healthy domestic shorthair cats using plain digital thoracic radiographs.

Methods: The planimetric cardiothoracic ratio, calculated by comparing the areas of the cardiac and thoracic cavity silhouettes, was used to assess the cardiac size.

Results: Planimetric cardiothoracic ratios varied significantly across radiographic views and respiratory phases. In the right lateral view, the mean end-inspiratory ratio was 22.17% (range, 17.42% to 27.02%), increasing to 25.51% (range, 20.47% to 32.6%) at end expiration. The left lateral view showed a similar pattern, with mean values of 21.15% (range, 18.07% to 25.5%) at end inspiration and 24.28% (range, 20.34% to 29.19%) at end expiration. Dorsoventral and ventrodorsal views exhibited higher ratios, with mean end-inspiratory values of 28.31% (range, 24.43% to 38.85%) and 27.96% (range, 22.96% to 33.57%), respectively, increasing to 32.70% (range, 27.91% to 42.92%) and 31.56% (range, 24.71% to 45.24%) at end expiration.

Clinical relevance: This study provides reference values for cardiac size based on the planimetric cardiothoracic ratio. Given the distinct contrast between the cardiac and thoracic silhouettes and the ease of calculation, this ratio may serve as a useful tool for assessing cardiac size in cats.

Conclusions: Potential influence of general anesthesia and the specific phase of the cardiac cycle on the cardiac silhouette measurements, as well as the possibility of subtle misalignments or rotational errors during image acquisition, could compromise the accuracy of cardiothoracic measurements. The reliability of the planimetric cardiothoracic ratio in reflecting cardiac size changes in feline heart disease necessitates additional study.

We evaluated bovine respiratory disease vaccine trials in feedlot cattle and found that most (19 of 34 [56%]) publications (describing 26 of 43 [60%] trials) labeled the control group as "unvaccinated" or similar terms even when all cattle in the trial received vaccine(s) at feedlot arrival. Additionally, 38 of 44 (86%) publications (describing 31 of 53 [58%] trials) reported statistical comparisons of bovine respiratory disease vaccines that did not mention the respiratory vaccines that all cattle received at feedlot arrival. Trial authors should report animal health products given to all cattle in a trial, in the abstract, methods, and results sections, to prevent misinterpretation of the actual comparisons investigated.

Objective: Comparison of a veterinary glucometer (AlphaTRAK 2 [AT-2]) and 2 human glucometers (FreeStyle Libre 2 [FS-] and FreeStyle Libre 14 [FS-14]) to an automated, wet-chemistry analyzer (reference analyzer).

Methods: This was a prospective observational study at Tufts Cummings School of Veterinary Medicine between January 2021 and September 2022 and included 187 client and staff-owned dogs. Following venipuncture, 3 glucometers (FS-14, FS-2, and AT-2) were used to measure blood glucose, and the reference analyzer was used to measure serum glucose.

Results: Compared to the reference analyzer, the FS-2 and FS-14 glucometers had a negative bias (mean difference estimates: FS-2, -25.01 mg/dL [95% CI, -60.4 to 10.3]; FS-14, -23.6 mg/dL [95% CI, -60.7 to 13.5]), while the AT-2 glucometer had a positive bias (mean difference estimates: 15.4 mg/dL [95% CI, -41.1 to 72.2]). All glucometers showed significant constant and proportional biases based on Passing-Bablok regression with constant biases of -12.3, -10.05, and -14.25 for the FS-2, FS-14, and AT-2, respectively. Most results were within zone A (FS-2, 50.3%; FS-14, 54.5%; AT-2, 70.1%) and B (FS-2, 49.7%; FS-14, 45.5%; AT-2, 26.2%) of the Clarke error grid. The AT-2 produced values within zone C (1.6%) and zone D (2.1%).

Conclusions: All glucometers correlated with the reference analyzer and were clinically useful. As the AT-2 glucometer produced values in the Clarke error grid zones C and D, serum glucose should be measured when results are unexpected or influence the treatment regimen.

Clinical relevance: Despite potential biases, owners can use FS-2 and FS-14 glucometers to verify sensor readings in dogs using continuous glucose monitoring devices.

Objective: To measure repeatability within and between sessions of the Timed Up and Go (TUG) test in geriatric dogs and investigate associations between TUG times and home activity as measured by accelerometry.

Methods: Geriatric dogs were recruited in April 2024 to perform 2 sessions of TUG testing 20 days apart. Each session consisted of 3 trials separated by 1-minute rest periods. Dogs wore collar-mounted accelerometers between sessions. Client-specific outcome measures, including Canine Brief Pain Inventory and Liverpool Osteoarthritis for Dogs, were compared between sessions to ensure functional stability. Repeatability was evaluated using intraclass correlation and Bland-Altman approaches.

Results: 30 dogs were enrolled, of which 24 (median age, 13 years; median weight, 26 kg) met inclusion criteria for analyses. For all within- and between-sessions testing, coefficients of repeatability were < 1.63 seconds, intraclass correlation coefficients were > 0.92, and coefficients of variation were < 10%. Vigorous activity was negatively correlated with TUG times for both sessions (ρ = -0.5). No differences in client-specific outcome measures between sessions and no other correlations between activity measures and TUG times were detected.

Conclusions: The TUG test is repeatable within and between sessions in functionally stable geriatric dogs; however, differences of 2 seconds or less may represent normal variation. In-clinic TUG times correlate to vigorous activity at home, and both measures may be reflective of short-duration maximal capacity effort.

Clinical relevance: This study further supports the TUG test as a reliable and valid measure of canine geriatric function.