American journal of veterinary research最新文献

Objective: To determine the population variability in dextromethorphan metabolism by cytochrome (CY) P450 2D15 (CYP2D15) in dogs.

Methods: Healthy pet dogs were recruited from 2018 through 2024 from the Inland Pacific Northwest and phenotyped by orally administering the Program in Individualized Medicine cocktail, which contains dextromethorphan, a CYP2D15-specific probe drug. Glucuronidase-treated urine samples collected 6 hours after dosing were assayed for dextromethorphan and dextrorphan concentrations. Log-transformed metabolic ratios of dextrorphan divided by dextromethorphan (DOR/DXM Log MRs) were calculated. Dogs were genotyped for 5 missense CYP2D15 variants. Univariate and multivariate statistical approaches were used to evaluate associations between DOR/DXM Log MRs and demographic variables.

Results: 105 dogs, including 34 mixed breeds and 71 dogs from 20 different owner-designated breeds, were enrolled and completed the study. There was a wide distribution of DOR/DXM Log MRs, from 0.97 to 2.76, representing a log unit range of 1.8 (63-fold variation DOR/DXM Log MRs). Log-transformed metabolic ratios of dextrorphan divided by dextromethorphan were normally distributed and unimodal. The mean (± SD) DOR/DXM Log MR was 2.04 ± 0.37. Multiple linear regression analysis showed significant association (R2 = 0.16) between DOR/DXM Log MRs and dog breed for Golden Retrievers (2.26 ± 0.29; N = 23) and Pugs (1.47 ± 0.29; N = 3). Log-transformed metabolic ratios of dextrorphan divided by dextromethorphan were not associated with dog sex, age, weight, or genotype.

Conclusions: There is substantial variability in DOR/DXM Log MR values among individuals, which can be partially attributed to differences between breeds.

Clinical relevance: These findings predict high variability in the metabolism of drugs by CYP2D15 associated with differences between dog breeds.

Objective: To assess the effectiveness of cleaning protocols and support infection prevention efforts, we instituted ATP bioluminometer monitoring at the University of Minnesota Veterinary Medical Center. Our objective with this serial cross-sectional study was to summarize our ATP bioluminescence reading from animal and human contact areas and the impact of seasonality.

Methods: From April 2020 through November 2023, swabs were collected from common contact surfaces at the hospital. Using the 3M Clean-Trace ATP Luminometer, relative light units (RLUs) served as a surrogate for an assessment of hygiene. Relative light unit values were compared by location, season, and "animal contact" or "human contact" surfaces. A mixed model compared RLU levels across different locations and dates.

Results: ATP readings varied across locations, ranging from 5 to 301,158 RLUs, with a mean of 1,441.14 (± 8,951.79), a median of 494, and an IQR of 1,138. Most readings were below 1,000 RLUs (67%), and 37% were below 300 RLUs. Animal contact areas had lower RLU readings compared to human contact areas. The mixed model identified statistically significant variable RLU values by location but not by season.

Conclusions: We observed a wide variation in median RLU values across the sampled locations. This is to be expected since hospital environments are dynamic, with varied animal and human interactions throughout the day as well as changing staffing patterns and patient volumes across different seasons.

Clinical relevance: Maintaining high hygiene standards is crucial for patient well-being and reducing the risk of healthcare-associated, zoonotic, and antimicrobial-resistant infections. The use of the ATP bioluminometer is one tool to reduce healthcare-associated infections and support better patient outcomes.

Objective: To evaluate IV indocyanine green (ICG) near-infrared fluorescence (NIRF) imaging to identify normal canine parathyroid tissue.

Methods: A cumulative effect study followed by a dose evaluation study with 8 purpose-bred dogs was performed from February through April 2023. Dogs were randomized to receive IV ICG at 0.2, 0.3, or 0.4 mg/kg after the thyroid and parathyroid glands were exposed. A NIRF endoscope positioned 8 cm above the thyroid-parathyroid complex obtained images. Subjective and objective measures of fluorescence were recorded and compared for the thyroid gland, external parathyroid gland, and internal parathyroid gland.

Results: Repeated ICG administration did not affect time to peak fluorescence but increased peak parathyroid gland fluorescence. Subjective fluorescence scores of the parathyroid glands were significantly higher in monochromatic modality compared to other ICG-NIRF modalities. Initial fluorescence was immediate for all glands. Mean time to peak objective fluorescence was 0.2 to 1.9 minutes. Higher ICG doses generally had higher peak fluorescence than lower ICG doses. Indocyanine green-NIRF did not consistently distinguish normal parathyroid glands from thyroid tissue.

Conclusions: ICG-NIRF at 0.2 to 0.4 mg/kg effectively fluoresces normal parathyroid glands in dogs, although the subjective fluorescence achieved in the parathyroid glands is similar to fluorescence in the adjacent thyroid glands. Parathyroid fluorescence varied substantially between ICG-NIRF modality, with the highest fluorescence observed in the monochromatic modality.

Clinical relevance: ICG-NIRF may aid in intraoperative localization of parathyroid glands, particularly the identification of ectopic parathyroid tissue. Further evaluation of ICG-NIRF for the identification of pathologic parathyroid tissue in clinical patients is indicated.

Objective: To describe the use of laparoscopic ultrasound (LUS) for evaluation of the liver in dogs with clinical liver disease and to compare the findings of LUS to transabdominal ultrasound (TUS).

Methods: 8 client-owned dogs presenting for laparoscopic liver biopsies due to clinical liver disease were enrolled. All dogs underwent TUS, and liver lesions were identified, localized, and quantified per presumed liver lobe. Laparoscopic examination and LUS of the liver were performed, and liver lesions were identified, localized, and quantified. Laparoscopic liver biopsies were obtained and submitted for histopathological analysis, copper analysis, and culture and susceptibility.

Results: The median time to perform hepatobiliary TUS was 10 minutes (IQR, 7.5 to 12 minutes), and the median time to perform LUS and laparoscopic examination of the liver was 19.5 minutes (IQR, 17.8 to 23.5 minutes). The number of lesions identified on LUS versus TUS was significantly different, with 5 dogs having an additional 28 lesions identified on LUS that were not found on TUS. The diameter of lesions identified on TUS and LUS ranged from 0.3 to 4.5 cm and 0.1 to 4.1 cm, respectively. In 2 dogs, LUS was used to guide the biopsy of liver lesions that were not grossly appreciable on laparoscopic examination.

Conclusions: LUS identifies more liver lesions compared to TUS and can be used to guide the biopsy of lesions that are not grossly appreciable laparoscopically.

Clinical relevance: LUS should be considered when staging patients with hepatobiliary neoplasia and may result in the identification of additional liver lesions missed on preoperative imaging.

Objective: To evaluate the accuracy of dog positioning before total hip replacement (THR) and the influence of experience and dog body condition score (BCS) on positioning accuracy.

Methods: 6 experienced THR surgeons and 11 veterinarians without THR experience positioned 4 cadavers (2 each with BCSs of 4/9 and 6/9) for THR 3 times using a vacuum bean bag. Accuracy was evaluated using fluoroscopy in 2 orthogonal planes: the transverse and dorsal planes.

Results: Mean positioning error was < 4° in both the transverse and dorsal planes. The mean deviation in the transverse plane for veterinarians with THR experience (3.6°) did not differ from the deviation for veterinarians without experience (3.8°; P = .398). The mean absolute deviation in the dorsal plane for veterinarians with THR experience (3.2°) did not differ from the mean absolute deviation for veterinarians without experience (3.7°; P = .930). Malpositioning > 10° in either plane occurred in 17 of 204 positionings (8%) and did not differ in frequency among experienced and inexperienced veterinarians. No difference in positioning accuracy was noted between cadaver BCS groups.

Conclusions: Freehand patient positioning before THR is generally precise and does not appear to improve with additional experience or lean patient BCS.

Clinical relevance: Most dogs positioned using a vacuum bean bag and freehand (nonfluoroscopy guided) positioning are accurately positioned, and positioning errors > 10° occur < 10% of the time. Positioning accuracy may not increase with lean patient BCS or additional experience for veterinary surgeons doing THR.

Objective: Determine pharmacokinetic parameters of meloxicam in red kangaroos following a single IM or PO dose.

Methods: In the spring of 2024, following a pilot study to determine the appropriate dosage, a managed population of clinically healthy adult or subadult red kangaroos at the Nashville Zoo received a 0.2-mg/kg dose of meloxicam, IM or PO. Four additional kangaroos received a 0.2-mg/kg dose of meloxicam, IV, to establish bioavailability. Blood samples were obtained under manual restraint over 48 hours, using a sparse sampling method. Plasma meloxicam concentration was determined using HPLC. Plasma meloxicam time-concentration profiles were established using a non-compartmental pharmacokinetic analysis.

Results: 15 kangaroos were included in this study. Eight kangaroos were assigned to the IM group, and 8 were assigned to the PO group. Pharmacokinetic parameters were time to the maximum observed plasma concentration (tmax) = 0.5 hours, maximum plasma concentration (Cmax) = 1.071 μg/mL, terminal half-life (t½) = 13.03 hours, elimination rate constant (λz) = 0.05 1/h, area under the plasma concentration-versus-time curve from time 0 to last point (AUC0-last) = 11.643 h·μg/mL, area under the plasma concentration-versus-time curve from time 0 to infinity (AUC0-∞) = 12.460 h·μg/mL, bioavailability = 129%, and apparent volume of distribution after extravascular administration (V/F) = 234 mL/kg, and tmax = 6 hours, Cmax = 0.445 μg/mL, t1/2 = 9.90 hours, λz = 0.07 1/h, AUC0-last = 6.666 h·μg/mL, AUC0-∞ = 7.023 h·μg/mL, bioavailability = 73%, and V/F = 557 mL/kg for the IM and PO groups, respectively. One kangaroo collapsed and died approximately 15 minutes following administration of an IV dose of meloxicam. Necropsy revealed intracranial hemorrhage.

Conclusions: The Cmax and t1/2 of meloxicam were greater in the IM group than the PO group. When dosed IM, plasma meloxicam concentrations reached levels reported to be therapeutic in other species, while this was inconsistently achieved with PO dosing.

Clinical relevance: IM meloxicam may offer advantages to PO dosing due to the greater Cmax and longer t1/2. Nonsteroidal anti-inflammatory drugs are known to decrease platelet function, and it is unknown if red kangaroos are at increased risk for hemorrhage following the administration of meloxicam compared to other species.

Objective: To establish a model of Escherichia coli-induced bovine mammary gland inflammation and investigate alterations in protein expression in bovine mammary glands under different health conditions.

Methods: 6 Chinese Holstein cows were selected and randomly assigned to 2 groups. Bovine mammary glands were induced with either 105 CFU/mL E coli (n = 3) or 1 X PBS (n = 3), and label-free quantitative proteomics was applied to explore the effect of E coli on the expression of proteins in bovine mammary glands. Then, these data were combined with transcriptome sequencing data for integrative analysis.

Results: A total of 944 differentially expressed proteins (DEPs) were identified; 588 proteins were upregulated and 356 were downregulated in mastitis tissues compared to healthy tissues. Gene Ontology functional annotations unveiled that the identified DEPs were predominantly enriched in processes, such as the single-organism metabolic process, extracellular region, and catalytic activity. According to Kyoto Encyclopedia of Genes and Genomes enrichment analysis, DEPs were prominently enriched in pathways related to type I diabetes mellitus, graft-versus-host disease, and peroxisome signaling pathways. InterPro analysis identified that the most significantly enriched functional structural domains were the epidermal growth factor-like calcium-binding domains, C-type lectin folds, and C-type lectins. By combining transcriptomic with proteomics data, 7 (cytochrome P450 family 51 subfamily A member 1, ethanolamine kinase 1, carbonic anhydrase 2, complement factor H, indoleamine 2,3-dioxygenase 1, CD5, and IL-33) hub genes (proteins) closely associated with mastitis development were identified.

Conclusions: These findings offer a theoretical basis for understanding the molecular regulatory mechanisms underlying bovine mastitis.

Clinical relevance: Our study presents a promising approach to understanding the mechanism of E coli infection, with a particular focus on the induction of bovine mastitis.

Objective: To assess the frequency of aseptic protocol breaches (APBs) among veterinary students scrubbing, gowning, and gloving into surgery and identify factors that may be associated with APBs.

Methods: This was an observational cross-sectional study. Students on clinical rotations at an academic small animal teaching hospital from May to July 2023 in the services of Orthopedic, Soft Tissue, Oncologic, and Neurologic Surgery were observed while scrubbing, gowning, and gloving into surgery, and APBs and donning times were recorded. Stage of rotation (early vs late), service type, duration of donning surgical attire, and previous surgical experience were also recorded. The χ2 and points biserial tests were used to assess for associations between APBs and the aforementioned factors.

Results: At least 1 APB was noted in 45 (46.3%) of the 96 procedures observed. The most common mistakes noted were contact of the sterile towel onto nonsterile surfaces (17.7%), contact of the gown with nonsterile surfaces (17.7%), touching sterile objects with bare hands (12.5%), and improper scrubbing technique (17.4%). There was no association between APBs and service type, previous scrub experience, or stage of rotation. Those who made an APB had longer gowning and gloving times, 4.60 (1.40) minutes, than those who did not make an APB, 3.71 (0.91) minutes.

Conclusions: These findings demonstrate that APBs are common among veterinary students and highlight reasons for contamination during scrubbing, gloving, and gowning.

Clinical relevance: The data may be used to help improve asepsis protocols.

Objective: The purpose of this research was to examine the feasibility of utilizing generative adversarial networks (GANs) to generate accurate pseudo-CT images for dogs.

Methods: This study used head standard CT images and T1-weighted transverse with contrast 3-D fast spoiled gradient echo head MRI images from 45 nonbrachycephalic dogs that received treatment between 2014 and 2023. Two conditional GANs (CGANs), one with a U-Net generator and a PatchGAN discriminator and another with a residual neural network (ResNet) U-Net generator and ResNet discriminator were used to generate the pseudo-CT images.

Results: The CGAN with a ResNet U-Net generator and ResNet discriminator had an average mean absolute error of 109.5 ± 153.7 HU, average peak signal-to-noise ratio of 21.2 ± 4.31 dB, normalized mutual information of 0.89 ± 0.05, and dice similarity coefficient of 0.91 ± 0.12. The dice similarity coefficient for the bone was 0.71 ± 0.17. Qualitative results indicated that the most common ranking was "slightly similar" for both models. The CGAN with a ResNet U-Net generator and ResNet discriminator produced more accurate pseudo-CT images than the CGAN with a U-Net generator and PatchGAN discriminator.

Conclusions: The study concludes that CGAN can generate relatively accurate pseudo-CT images but suggests exploring alternative GAN extensions.

Clinical relevance: Implementing generative learning into veterinary radiation therapy planning demonstrates the potential to reduce imaging costs and time.

Objective: To assess the ability to visually estimate the fractional shortening in dogs and the impact of experience on those assessments.

Methods: Right parasternal short- and long-axis cine loops from 25 dogs with varying fractional shortening (6.9% to 61.2%) were distributed online to observers with different levels of training in anesthesiology or cardiology and different experience (advanced, intermediate, beginner, or none) interpreting echocardiography. Observers were asked to estimate the fractional shortening and assign 1 of 5 categories: hyperdynamic (> 45%), normal (25% to 45%), mildly decreased (20% to 24%), moderately decreased (15% to 19%), or severely decreased (< 15%). The answers for all cases combined were graded as correct/incorrect based on each of the 5 fractional shortening categories and compared between participants of each level experience. In addition, answers were reanalyzed using 2 categories for fractional shortening, ≥ 20% and < 20%, to test the identification of clinically important decreased function.

Results: Answers from 240 participants were received. The overall rate of correct answers averaged between 45% and 47% for all levels of experience. This improved from 79% to 83% across all levels of experience when a 2-category scale was used. Participants with advanced experience performed slightly better. The success rate for identifying fractional shortening < 20% when the dogs had moderate and severe decreases was 50% to 54% and 92% to 96%, respectively.

Conclusions: Visual estimations of the fractional shortening can be used reliably to identify cases of severe but not moderately decreased function.

Clinical relevance: A basic echocardiographic exam may identify dogs with severely decreased fractional shortening. Measurements are required to distinguish those with moderate function.