American journal of veterinary research最新文献

Objective: To investigate the sonographic effects of alfaxalone and butorphanol alone and in combination on feline splenic size, shape, margins, echogenicity, echotexture, and blood flow. Our hypothesis was that alfaxalone alone and in combination would be associated with an increase in splenic size and blood flow and a nonhomogenous echotexture.

Methods: This was a randomized, prospective crossover study. 8 healthy adult cats were all injected IM with each of the following protocols in a randomized fashion, with a minimum of 7 days of washout between each protocol-alfaxalone 2 mg/kg, butorphanol 0.2 mg/kg, and the 2 in combination. Splenic ultrasounds were performed before drug administration, then every 15 minutes for 1 hour subsequently. Ultrasound images were interpreted by 2 board-certified radiologists. Heart rate, respiratory rate, and feline multiparametric sedation scores (FMSS) were also recorded. Splenic appearance, heart rate, respiratory rate, and FMSS were compared to baseline.

Results: There were no significant changes detected in splenic margins, shape, echogenicity, echotexture, or blood flow compared to baseline for any of the protocols. An increase in splenic size occurred for all protocols, with no significant difference between them. Both protocols containing alfaxalone caused a significant increase in FMSS; butorphanol alone did not.

Conclusions: Alfaxalone did not affect splenic margins, echotexture, echogenicity, or blood flow; however, a mild and transient increase in splenic size was noted.

Clinical relevance: Alfaxalone in combination with butorphanol provided the best sedation and can be used in the sedation of healthy cats for splenic ultrasound without significant changes to splenic appearance. Splenomegaly may occur but is unlikely to be of clinical significance.

Objective: To evaluate the use of collar-mounted accelerometers to objectively monitor treatment outcomes in canine pruritus.

Methods: Observational data from 1,803 dogs from 2019 through 2023 were retrospectively analyzed to evaluate the efficacy of collar-mounted accelerometers to assess treatment efficacy for pruritic canine skin diseases. Accelerometer measurements were joined to electronic health records to establish symptoms, diagnoses, and interventions. A directed acyclic graph was used to identify relevant variables to control for, and linear regression was used to model the pruritic behaviors before and after intervention.

Results: Significant reductions in pruritic behaviors, particularly scratching and licking, were observed following interventions. Antibody and immunosuppressant treatments exhibited the most pronounced effects on scratching behavior, with a reduction in scratching of up to 40.9% and 23.4%, retrospectively, in the 30 days following intervention relative to the 14 days prior.

Conclusions: Collar-mounted accelerometers used to measure pruritic behaviors can detect the effects of interventions for canine pruritus.

Clinical relevance: Pruritus is a common symptom of canine skin diseases, such as atopic dermatitis or allergic dermatitis, which can be difficult to diagnose and manage. This study highlights the use of collar-mounted accelerometers to objectively monitor treatment outcomes for canine pruritus, providing valuable insights into treatment effectiveness that could allow veterinarians and pet owners to optimize management strategies to alleviate the burden of this challenging condition.

Objective: To investigate the disposition of enrofloxacin and its active metabolite, ciprofloxacin, in plasma, pulmonary epithelial lining fluid (PELF), peritoneal fluid, and CSF in horses following IV administration of enrofloxacin at doses of 5 mg/kg and 7.5 mg/kg of body weight.

Methods: 6 healthy, mature mares were randomly assigned to receive a single dose of enrofloxacin at either 5 mg/kg or 7.5 mg/kg in a crossover design with a washout period of 10 days. Concentrations of enrofloxacin and ciprofloxacin were determined in plasma, PELF, peritoneal fluid, and CSF.

Results: Both doses of enrofloxacin were generally well tolerated. One horse developed focal, self-limiting limb edema. The median maximum concentration extrapolated to time 0 and area under the plasma concentration-versus-time curve from time 0 to the last quantifiable time point (24 hours) for enrofloxacin in plasma were significantly greater when horses were given enrofloxacin at 7.5 mg/kg. Similarly, the median elimination rate constant, half-life of the terminal phase, peak serum concentration (Cmax), area under the plasma concentration-versus-time curve from time 0 to the last quantifiable time point (24 hours), area under the plasma concentration-versus-time curve extrapolated to infinity, and mean residence time for ciprofloxacin in plasma were significantly greater following administration of enrofloxacin at 7.5 mg/kg. There were no significant differences between doses in any of the measured pharmacokinetic variables in PELF.

Conclusions: There was no apparent pharmacokinetic advantage of enrofloxacin at the 7.5-mg/kg dose for susceptible isolates; however, this dose achieved higher concentrations and prolonged persistence in fluid matrices. Further studies are required to evaluate repeated administration at this dose for tolerability and clinical efficacy.

Clinical relevance: Despite the wide use of enrofloxacin in horses, pharmacokinetic data is limited. This study provides pharmacokinetic data that can be used in a clinical setting.

Objective: To evaluate endoscopy for detection of epithelial remnants within the feline tympanic bulla following ventral bulla osteotomy (VBO) and to report the most likely locations within the bulla for epithelial remnants to occur.

Methods: This was a single-center experimental cadaveric study. 10 VBO procedures were performed by 5 board-certified surgeons in 5 feline cadavers. Following completion, a 1.9-mm, 30° rigid endoscope was inserted into the rostral, caudal, dorsal, lateral, and medial section, and images were acquired. A blinded observer evaluated the endoscopic images for epithelial remnants, and the percentage of the section containing epithelial remnants was measured. The mean and SD of distribution of epithelial remnants were calculated for each section.

Results: Remnant epithelium was noted in at least 1 section in each cadaver. The dorsal section was the most common to have epithelial remnants identified (10 of 10), whereas the lateral (5 of 10) and medial (5 of 10) were the least common. The lateral section contained the most epithelial remnants (6.9 ± 11.42%), whereas the caudal section contained the least (1.2 ± 1.42%).

Conclusions: The use of a 1.9-mm, 30° endoscope was feasible for evaluation and identification of epithelial remnants in a feline tympanic bulla following VBO. Epithelial remnants were consistently identified in all sections with endoscopic assistance.

Clinical relevance: Endoscopy following completion of a VBO may be considered to ensure complete removal of epithelium.

Objective: To establish a reference interval for amino acid profiles for healthy red wolves (Canis rufus).

Methods: Heparinized plasma of 48 red wolves was collected between August 2023 and April 2024 and sent to the University of California-Davis Amino Acid Laboratory for analysis. Reference intervals were created using the published American Society for Veterinary Clinical Pathology reference interval guidelines. Data were analyzed via Gaussian data distribution, and parametric statistical methods were used to produce a 90% CI of reference limits. The means of the red wolf intervals created were compared to those of the domestic dog using a z test.

Results: Reference intervals were created for red wolves (n = 48). Upon completion of the z test, 11 of 21 amino acids were found to be statistically significantly different compared to those of the domestic dog.

Conclusions: A reference interval was created for red wolves. The red wolf amino acid profiles are different than those of the domestic dog, with 52% (11/21) of the profiles being statistically different.

Clinical relevance: Red wolf amino acid profiles should not be compared to those of the domestic dog reference intervals due to the significant difference between profiles.

Objective: To describe a technique for ultrasound-guided celiac plexus block in horses and characterize its effect on intestinal motility in healthy horses.

Methods: This study was conducted from January 2022 through June 2022. In phase 1 (dye study), an ultrasound-guided technique was optimized, and dye deposition around the celiac plexus branches was evaluated via postmortem dissection in 6 horses. In phase 2 (experimental study), 6 healthy horses were fasted and sedated with 0.6 mg/kg xylazine, IV (experiment 1). After a washout period, the ultrasound-guided celiac plexus block with lidocaine 1% (1.3 mg/kg) was performed after sedation (experiment 2). In both experiments, intestinal motility was recorded via transcutaneous ultrasound before sedation, after sedation (15, 30, and 45 minutes and 1, 2, 3, 4, and 6 hours), and 1 hour after refeeding. Ultrasound video recordings were blinded of horse identity, day, and time; randomly arranged; and scored using a specifically designed motility scoring system.

Results: Postmortem dissection confirmed dye deposition over the celiac plexus branches. In phase 2, a significant increase in intestinal motility was detected after the celiac plexus block compared to sedation alone, with a peak between 1 and 3 hours postblock (13.58 ± 2.8 vs 3.75 ± 2.4 at baseline); motility remained increased up to 6 hours. The only side effect observed was a transient hindlimb ataxia in 1 horse.

Conclusions: Ultrasound-guided celiac plexus block is feasible and induces an increase in intestinal motility in healthy horses without significant complications.

Clinical relevance: This technique can be considered in multimodal management of colic and paralytic ileus.

Objective: To determine the relationship between hoof surface (HS), hoof wall (HW), and lamellar tissue (LAM) temperature during distal limb cooling and evaluate 4 cooling methods in ambulatory horses over extended periods using HW to estimate LAM temperature.

Methods: 8 healthy, university-owned horses were enrolled. Temperature was measured over 4 hours at LAM, HS, and HW for 4 cooling methods: ice sleeve (SLEEVE), ice pack system (ICEPACK), low-volume ice water immersion (LV-IMMERSION), and high-volume ice water immersion (HV-IMMERSION). The relationship between HW, HS, and LAM was mathematically modeled, generating a method-specific correction factor to predict LAM based on HW. Hoof wall temperature was then measured over 8 hours with horses free in a stall (LAM was estimated using HW). Mixed-effects linear regression was used to compare cooling methods.

Results: HV-IMMERSION and LV-IMMERSION significantly decreased LAM temperature over 4 hours (P < .001), whereas ICEPACK and SLEEVE did not. Lamellar tissue temperature estimated using HW showed good concordance (ρc = 0.93 [0.93 to 0.94]; P < .001) and correlation (r = 0.93; P < .001) with measured LAM temperature. In horses free in the stall for 8 hours, the estimated LAM temperature decreased significantly with HV-IMMERSION (-20.4 °C [-22.9 to -17.8]) and LV-IMMERSION (-14.9 °C [-17.7 to -12.1]) compared to control (32.7 °C [32.2 to 33.2]; P < .001) but did not decrease with ICEPACK (-2.7 °C [-5.6 to -0.3]; P < .08) or SLEEVE (-1.8 °C [-5.6 to -2.0]; P < .4).

Conclusions: HV-IMMERSION and LV-IMMERSION were superior to ICEPACK and SLEEVE for lamellar cooling.

Clinical relevance: Immersion of the distal limb in ice and water is most effective for cooling the digital lamellae under clinically relevant conditions.

Objective: To evaluate the impact of intrahepatic portal vein branching (IHPB)-grade assessment using preoperative CT angiography (CTA) on the surgical procedure and prognosis prediction for dogs with an extrahepatic portosystemic shunt (EHPSS).

Methods: This study involved 146 client-owned dogs with EHPSS. The shunt morphology of EHPSS and IHPB grades was determined using CTA. All dogs underwent surgical attenuation of the shunt with intraoperative portal vein pressure (PVP) measurement, followed by a liver biopsy of the left lateral lobe. The preoperative CTA findings were analyzed according to surgical procedures, intraoperative PVP, hepatic histopathology, and postoperative complications.

Results: The grade of IHPB did not correlate with baseline PVP while it significantly correlated with PVP during temporary occlusion and the difference in PVP between before and during the temporary occlusion. The grade of IHPB and PVP had significant differences between the dogs with partial ligation compared with those with complete ligation. The portal vein hypoplasia score on histopathology was generally higher in the dogs with low-grade IHPB than in those with high-grade IHPB. The IHPB grade had no significant influence on postoperative complications and prognosis.

Conclusions: This study demonstrated that although the grade assessment system of IHPB using preoperative CTA was unable to predict the prognosis of dogs with a single EHPSS, it may be useful for determining surgical procedure selection.

Clinical relevance: Preoperative CTA is suggested to not only be useful for the diagnosis and classification of EHPSS but also for surgical planning of EHPSS in dogs.

Objective: This study investigates whether urinary cortisol (UC) and UC-to-creatinine ratio (UCCR) perform better than basal serum cortisol (BSC) in identifying dogs with hypoadrenocorticism (HA).

Methods: A retrospective, multicenter study with 120 client-owned dogs included: 20 with HA, 42 healthy, and 60 with diseases mimicking HA. The UC and UCCR were determined on urine samples using a chemiluminescent enzyme immunoassay. The diagnostic performance of the UC and UCCR were assessed based on receiver operating characteristics (ROC) curves.

Results: A cutoff value of UC < 2 µg/dL revealed 100% sensitivity (95% CI, 83.2 to 100) and 90.0% specificity (95% CI, 79.5 to 96.2) in diagnosing HA. A cutoff value of UCCR < 8.5 X 10-6 revealed 100% sensitivity (95% CI, 83.1 to 100) and 71.7% specificity (95% CI, 58.6 to 82.6) in diagnosing HA. A cutoff value of BSC < 2 µg/dL and < 1 µg/dL revealed 100% sensitivity (95% CI, 83.2 to 100) and 51.7% specificity (95% CI, 38.5 to 64.8) and 100% sensitivity (95% CI, 83.9 to 100) and 90% specificity (95% CI, 79.8 to 95.3) in diagnosing HA, respectively.

Conclusions: BSC < 1 µg/dL showed the same sensitivity but higher specificity than BSC < 2 µg/dL. The UC < 2 µg/dL showed noninferior performance compared with the BSC < 1 µg/dL.

Clinical relevance: UC should be considered a promising screening test for canine HA.