American journal of veterinary research最新文献

Objective: To evaluate the thermal antinociceptive effects of methadone after IM administration to orange-winged Amazon parrots (Amazona amazonica).

Methods: 8 Amazon parrots received IM methadone hydrochloride (1, 3, and 6 mg/kg) and saline (0.9% NaCl) solution in a masked randomized, within-subjects, balanced complete crossover experimental design. The thermal foot withdrawal threshold (TFWT) was determined 5 minutes before (baseline) and 0.5, 1.5, 3, and 6 hours after treatment administration. Agitation-sedation scores and other adverse effects were evaluated in the test box at each time point before each TFWT.

Results: Methadone at 6 mg/kg significantly increased TFWT when compared with control by an average of 1.9 ± 0.5 °C accounting for baseline values. Methadone also caused agitation for 1, 3, and 6 mg/kg at 0.5 to 1.5 hours compared to control and increased nausea-like behavior (opening the beak and moving the tongue back and forth) for all doses up to 3 hours posttreatment compared to control. Although ataxia was not significant overall, some birds showed ataxia at 0.5 and 1.5 hours following administration of 6 mg/kg.

Conclusions: Methadone administered IM to orange-winged Amazon parrots at 6 mg/kg significantly increased TFWT and appears to have a rapid onset and relatively short duration. Agitation and nausea-like behavior were also observed at lower doses.

Clinical relevance: The benefit of rapid onset, potent analgesic effect, and added mechanisms of action to the opioid-mediated analgesia make methadone an added choice for clinical use in this species. However, these doses caused neuroexcitation with agitation and nausea-like behavior, which should be considered in clinical use.

Objective: To determine the diagnostic yield of abdominal ultrasound and thoracic radiographs in an otherwise systemically healthy population of dogs undergoing tibial plateau leveling osteotomy.

Methods: Medical records from 2 private-practice institutions were retrospectively reviewed to identify otherwise systemically healthy dogs undergoing an elective tibial plateau leveling osteotomy that were offered preoperative 3-view thoracic radiographs and/or abdominal ultrasound from June 1, 2019, through June 30, 2022. Multivariate statistical analysis was performed to compare the odds of diagnosing a new comorbidity and to analyze all patients that were offered preoperative imaging.

Results: A total of 258 client-owned dogs of various breeds were recorded between both hospitals. In total, 116 of 258 dogs (45.0%) solely received thoracic radiographs, 10 of 258 (3.9%) solely received abdominal ultrasound, and both were performed in 61 of 258 (23.6%). Eighty-seven of 258 dogs (33.7%) had either thoracic radiographs, abdominal ultrasound, or both performed preoperatively.

Conclusions: New comorbidities were diagnosed in 13.8% of patients with thoracic radiographs and in 70% of patients with abdominal ultrasound. Patients over the age of 12 years were more likely to have a new comorbidity diagnosed.

Clinical relevance: Abdominal ultrasound is 163 times more likely to lead to diagnosis of a new comorbidity when compared to thoracic radiographs, and the incidence of a new diagnosis was more likely in dogs over the age of 12.

Objective: To evaluate neuropathological changes in dogs with idiopathic epilepsy and history of focal seizures using previously described criteria for temporal lobe epilepsy (TLE) in humans and other animals.

Methods: This was a prospective descriptive study. Dogs of any age, sex, or breed with a history of idiopathic epilepsy and focal seizures were included. Immediately following euthanasia, dogs were perfused, and tissue was collected. Brains were sectioned, mounted, and stained. Nissl-stained slides were used for stereology, and Timm stain was used to evaluate for evidence of mossy fiber sprouting.

Results: 7 dogs were included in the final analysis. For stereological cell counts evaluating hilar neuron loss, no case was significantly lower in number of neurons. Additional analysis compared right and left to look for asymmetry, and none were significant (P = .259). Using Timm stain to evaluate mossy fiber sprouting, no cases showed extensive sprouting, and no asymmetry was detected between left and right hippocampi (P = .054).

Conclusions: In our cohort, while there were changes associated with seizures detected within the hippocampi, none were severe or consistent enough to qualify as TLE using the human criteria.

Clinical relevance: Our study focused on dogs with focal seizures as their main seizure presentation as that is the most common semiology in people with TLE. However, a future study could consider evaluating the neuropathology of dogs with asymmetric hippocampi detected on MRI. If TLE can be shown in dogs, then advanced treatment options, such as surgery or laser ablation, could be considered in refractory patients.

Objective: To describe and quantify selected radiographic findings of rabbits diagnosed with liver lobe torsion (LLT).

Methods: The study included 50 rabbits with an antemortem diagnosis of LLT with radiographs made within 72 hours of diagnosis via ultrasound. Medical records from 2010 to 2020 from 4 institutions were reviewed. A board-certified radiologist reviewed the radiographs. Radiographic evaluation of gastric size was assessed on the right lateral view (caudal extent of the stomach relative to the lumbar vertebral column, gastric height and width, and vertebral stomach score), as well as gastric content patterns and radiographic signs of intestinal dilation and content, hepatic rounding, and loss of serosal detail. Loss of abdominal serosal detail was compared to the presence of peritoneal fluid on ultrasound.

Results: 35 of 50 rabbits (70%) had a gastric height and gastric width sum height greater than or equal to the length from the L1 cranial endplate to the coxofemoral joint. The median vertebral stomach score was 8.8. The gastric content was mostly ingesta. A rounded margin along the right hepatic silhouette in the ventrodorsal view was identified in 30 of 50 rabbits (60%). Peritoneal fluid was correctly identified radiographically in 37 studies (74%), not appreciated but present in 7 (14%), correctly identified as not present in 4 (8%), and incorrectly identified in 2 (4%).

Conclusions: Radiographic findings suggested that gastric dilation with ingesta, a rounded right hepatic silhouette, and peritoneal fluid, although not always present, are common in rabbits with LLT.

Clinical relevance: Identification of these findings should prompt further diagnostic imaging.

Objective: To investigate whether a structured mindfulness training program could reduce anxiety and enhance academic performance among veterinary students in an anesthesiology course.

Methods: All students enrolled in a second-year veterinary anesthesiology course during 1 term were offered participation in the mindfulness program, with volunteers forming the intervention group and nonparticipants serving as a comparison group. Perceived stress, self-compassion, and depression were measured before and after the program using validated questionnaires, and academic performance was assessed via scores on the second midterm examination and final examination. The study followed an action research framework and employed a quasi-experimental design.

Results: After training, the intervention group demonstrated a substantial reduction in perceived stress and an increase in self-compassion, whereas the comparison group showed minimal change. Depression scores remained unchanged in both groups. On the second midterm, the mindfulness group's mean score exceeded that of controls by approximately 9 percentage points. By the final examination, all students had improved, and no significant score differences persisted.

Conclusions: Mindfulness training was associated with reduced perceived stress, enhanced self-compassion, and a transient improvement in midterm performance.

Clinical relevance: Mindfulness interventions may support veterinary students' well-being and academic success.

Objective: To elucidate the species-specific regulatory mechanisms of hydroxyacyl-CoA dehydrogenase alpha subunit (HADHA) in ruminant liver metabolism and to decipher the consequent metabolic-transcriptional network dysregulation using an integrated multiomics approach in a dairy cow hepatocyte model.

Methods: A loss-of-function study was conducted using transfecting primary hepatocytes isolated from dairy cows with HADHA-targeting small interfering RNA (n = 6). LC-MS+GC-MS metabolomics and transcriptomics were integrated and analyzed via orthogonal partial least squares-discriminant analysis, differential and enrichment analysis, and multiomics network analysis.

Results: HADHA knockdown induced profound metabolic reprogramming, identifying 692 differentially abundant metabolites and 736 differentially expressed genes. Key dysregulated metabolomic pathways included upregulation of forkhead box O signaling, tricarboxylic acid cycle, and butanoate metabolism and downregulation of glycolysis/gluconeogenesis and ATP-binding cassette transporters. This was evidenced by suppression of primary bile acids and accumulation of glyceroneogenesis markers. Transcriptomic analysis revealed downregulation of insulin response and nuclear factor κ B signaling and upregulation of phosphatidylinositol and phosphatidylinositol 3-kinase-protein kinase B signaling. Multiomics integration confirmed disruption in core pathways, including arginine and proline metabolism, nicotinate and nicotinamide metabolism, and cAMP signaling.

Conclusions: This study provides a comprehensive map of the HADHA-mediated regulatory network in the ruminant hepatocytes. Its depletion directly suppresses fatty acid oxidation and bile acid synthesis and rewires central carbon and lipid metabolism, leading to a state of metabolic imbalance.

Clinical relevance: The elucidated mechanisms establish a foundational basis for future research aimed at developing nutritional or genetic strategies to improve metabolic health in the dairy industry.

Objective: The objectives of this study were to evaluate whether the topical application of a maternal bovine (Bos taurus)-appeasing substance (mBAS) to laboratory dogs (Canis familiaris) would affect barking intensity, alter the prevalence of loud barking, or have adverse effects.

Methods: A controlled experiment with a repeated-measures design was performed with a convenience sample of 12 dogs from an existing research colony. The room housing the dogs served as the experimental unit across two 5-day treatment periods (one period for control and one for mBAS). A decibel meter recorded sound levels every 30 s to quantify barking intensity. Dogs with clinical signs of illness were excluded.

Results: A total of 22,502 decibel readings were recorded, and mBAS did not significantly affect decibel levels regardless of time of day or research day. Additionally, mBAS did not significantly affect loud barking. No adverse effects were noted, and no dogs were excluded from the study.

Conclusions: Our results suggest that mBAS does not meaningfully reduce vocalizations in kenneled laboratory dogs nor does it offer welfare benefits to dogs or human caretakers. The substance is well tolerated in this species and may be considered for future research endeavors in interspecies pheromonal communication.

Clinical relevance: Species-specific maternal pheromones can reduce stress-associated behaviors in animals, including vocalization intensity and frequency in dogs. Existing research suggests that interspecies pheromone use is beneficial, and while our data did not support this hypothesis, they contribute to the scientific understanding of this underexplored research area.

Objective: To measure intersegmental movement in the sagittal, dorsal, and transverse planes of the cranial thoracic to caudal thoracic, caudal thoracic to lumbar, and lumbar to sacral segments using range of motion and angular velocity as measures of quality of movement.

Methods: 6-degrees-of-freedom spinal motion was measured at the walk and trot in 3 sound Thoroughbred and Thoroughbred cross horses, and the data were pooled, giving a total of 54 gait cycles at walk and 33 at trot. These were compared against 8 cycles at walk and 13 at trot from 1 Thoroughbred horse that was confirmed as having moderate to severe impact and push-off lameness in the right hind limb.

Results: Both joint angles and angular velocities detected differences between the sound horses and the lame horse, with angular velocity showing notably greater differences in absolute values and percentages compared with joint angles.

Conclusions: The between-group differences indicated decreased quality of movement/control in the lame horse, and this was most apparent when trotting.

Clinical relevance: Intersegmental angular velocity is measured noninvasively and may be used to assess the quality of intersegmental movement in horses as it does in humans. Further investigation to assess angular velocity throughout treatment of topline dysfunction of the horse and its association with different lameness patterns is warranted.

Objective: To develop vertebral heart size (VHS) and vertebral left atrial size (VLAS) reference intervals in sighthounds.

Methods: Electronic medical records of IDEXX Telemedicine Consultants were searched for Rhodesian Ridgebacks, Borzois, Afghan Hounds, Salukis, and Basenjis undergoing thoracic radiography from January 1, 2021, through April 30, 2023. All measurements of VHS and VLAS were performed by the same board-certified cardiologist.

Results: 920 sighthounds (225 Rhodesian Ridgebacks, 196 Borzois, 190 Afghan Hounds, 159 Salukis, and 150 Basenjis) were identified, and 240 (56 Rhodesian Ridgebacks, 47 Borzois, 44 Afghan Hounds, 44 Salukis, and 49 Basenjis) met the inclusion criteria. The remaining 680 dogs were excluded because of malpositioning or incomplete radiographic studies (n = 456), extracardiac disease (139), or cardiac disease (85). The overall reference intervals for all 240 sighthounds were 9.0 to 11.2 vertebrae (v) for VHS and 1.7 to 2.6v for VLAS. Reference intervals were further determined by breed: Rhodesian Ridgeback, 9.3 to 11.5v for VHS and 1.8 to 2.4v for VLAS; Borzois, 8.8 to 10.9v for VHS and 1.7 to 2.3v for VLAS; Afghan Hound, 9.0 to 11.5v for VHS and 1.8 to 2.5v for VLAS; Salukis, 9.4 to 11.8v for VHS and 1.6 to 2.6v for VLAS; and Basenjis, 9.0 to 11.6v for VHS and 1.7 to 2.5v for VLAS.

Conclusions: Sighthounds have breed-specific VHS and VLAS reference intervals.

Clinical relevance: The reference ranges presented here could be a diagnostic aid to screen for cardiomegaly in these breeds.