American journal of veterinary research最新文献

Objective: To establish an echocardiographic technique in koi carp (Cyprinus carpio), compare cardiopulmonary parameters under manual restraint versus anesthesia, and provide a gross anatomical and histologic cardiac description.

Methods: A randomized, crossover echocardiography study was performed in 40 clinically healthy adult, unknown sex, privately owned koi carp on May 10 and 11 through June 26 and 27, 2021. Echocardiography was examined for each koi under manual restraint and isoeugenol at 50 ppm, with 3 measurements per examination performed by a radiologist and cardiologist. Two koi were euthanized for gross anatomic and histologic cardiac evaluation.

Results: Mean ejection fraction (EF), stroke volume (SV), and cardiac output (CO) were significantly lower, mean heart rate (HR) was significantly higher, and opercular rate (OPR) was decreased significantly in anesthetized compared to manually restrained koi. Poor reproducibility for EF and SV was observed.

Conclusions: Echocardiography was feasible in both manually restrained and anesthetized koi; however, this technique may best be applied to monitoring trends over time in individual fish due to low reproducibility. Significant differences in multiple cardiopulmonary parameters, including HR, EF, SV, CO, and OPR, were present between manually restrained and anesthetized koi. A gross anatomic and histologic cardiac description is provided for this species to pair with the echocardiographic images.

Clinical relevance: This study provides the first description of echocardiography, cardiac gross anatomy, and histology in koi. The results support echocardiography as a safe and practical noninvasive diagnostic for cardiac assessment in koi under both manual restraint and anesthesia.

Objective: To evaluate the in vivo spread of iodinated contrast following injections in the transversus abdominis plane (TAP) and rectus sheath in anesthetized dogs via computed tomography. Secondarily, the time of performing each block was compared.

Animals: 6 adult, purpose-bred Beagles.

Methods: In a prospective crossover study, dogs were administered injections either in the rectus sheath or transversus abdominis fascial plane in the same manner as a rectus sheath block (RSB) or TAP block using dilute iodinated contrast. Computed tomography scans were performed immediately following injection (time [T]-0) and at 3, 9, 18, and 30 minutes postinjection. Data regarding the spread in the cranial-caudal and lateral directions and time to perform the injections were compared between the 2 techniques using paired or 2-sample t tests.

Results: There was significantly greater spread in the cranial-caudal direction in the RSB group (62.9 ± 6.4 mm vs 54.8 ± 6.8 mm at T30; P = .009), whereas spread in the lateral direction was greater in the TAP group (37.3 ± 3.0 mm vs 48.6 ± 6.1 mm at T30; P < .0001). The RSB injection was performed in a more time-efficient manner than TAP injection (48.2 ± 3.2 seconds vs 82.3 ± 8.7 seconds; P = .03).

Conclusions: In living subjects, RSB injections resulted in greater cranial-caudal spread while TAP injections resulted in greater lateral spread. Rectus sheath block injections were performed in a more time efficient manner compared to a single point TAP injection in anesthetized dogs.

Clinical relevance: The RSB was performed in a more time-efficient manner and would likely result in greater coverage of the ventral midline. The TAP block would likely result in more significant regional anesthetic coverage of the lateral abdominal wall. Further studies are required to determine the degree of the clinical significance of these results.

Objective: To investigate whether liver compression (LC) could increase stroke volume (SV) by more than 15% in healthy, anesthetized dogs with hypovolemia and suggest LC as a novel method to evaluate fluid responsiveness.

Animals: 6 healthy Beagles.

Methods: This prospective, nonrandomized experimental study was conducted from November 2023 to February 2024. The dogs were anesthetized with isoflurane and mechanically ventilated under neuromuscular blockade. After instrumentation, the dogs underwent the following 4 experimental stages in a sequential, nonrandomized manner: stage 1, baseline; stage 2, 30% withdrawal of circulating blood volume; stage 3, 50% infusion of the collected blood; and stage 4, the remaining 50% infusion of the collected blood. At each stage, SV via pulmonary artery thermodilution and hemodynamic variables were measured before, during, and after the LC.

Results: In stage 2, LC significantly increased mean SV by 30%, from 6.9 to 9 mL/beat. Simultaneously, LC significantly increased mean arterial pressure by 11 mm Hg and mean central venous pressure by 2 mm Hg, while pulse pressure variation significantly decreased from 28% to 22%. In stages 1, 3, and 4, LC did not significantly change mean SV, mean arterial pressure, and pulse pressure variation; however, mean central venous pressure significantly increased during stage 3.

Clinical relevance: This study demonstrates that LC at 22 mm Hg for 1 minute could increase SV more than 15% in anesthetized, hypovolemic dogs and LC could be used as a novel method to evaluate fluid responsiveness.

Urothelial carcinoma (UC) is the most common urogenital cancer in dogs. With early diagnosis, the disease can be controlled, to reduce progression of disease, in most dogs with a good quality of life. MicroRNAs (miRNAs) have been identified as a potential diagnostic and prognostic tool due to their stability and presence in both bodily fluids and tissues. MiRNAs have been frequently researched in human medicine and human UC; however, few manuscripts regarding miRNAs in canine UC are available. A search was performed on both PubMed and Google Scholar evaluating original research manuscripts with experimentally validated results for the terms "canine" or "dog"; "urothelial carcinoma," "bladder cancer," "transitional cell carcinoma," "TCC," "MIBC," "IMBUC," or "BLCA"; and "miRNA" or "microRNA." We identified 3 peer-reviewed manuscripts evaluating miRNA expression in canine UC and compared the reported miRNA expression studies to human UC to identify experimentally validated targets of the dysregulated miRNA. In this review, we highlight the similarities and differences between what is reported in canine UC and human UC and discuss the literature gaps that call for further evaluation.

Objective: The objective of this study was to provide orientation values for fructosamine in adult llamas and to characterize relationships with other laboratory and clinical parameters.

Animals: Data from 22 healthy adult llamas of both sexes.

Methods: A retrospective study was conducted with the findings of a veterinary herd visit from August 2022. Fructosamine measured from plasma samples was characterized, and its relationships with clinical and laboratory diagnostic data was analyzed using descriptive statistics and correlation analysis.

Results: Fructosamine was 311 ± 34 µmol/L (mean ± SD), with a range of 254.8 to 409.2 µmol/L. Males showed significantly higher plasma fructosamine levels than females (P < .05). Plasma fructosamine revealed significant positive correlations with glucose, total protein, and albumin and also with PCV, hemoglobin, calcium, sodium, and selenium. Female llamas revealed further positive correlations with body condition scoring.

Clinical relevance: The results of this study can be used as orientation values for fructosamine in llamas. Fructosamine is used to distinguish acute hyperglycemia caused by stress from chronic hyperglycemia in other species, which might be caused by disorders of the glucose metabolism.

Objective: To investigate the effect of intranasal (IN) flunixin meglumine (FM) and intra-inguinal (IG) lidocaine on castration inflammation using prostaglandin E2 (PGE2) concentration as a biomarker.

Methods: This randomized controlled trial was conducted in March 2022. Blood was collected at -24, 1, and 24 hours postcastration for PGE2 quantification from 195 piglets that received 1 of 8 treatments: (1) saline (1.5 mL) applied IG and IN (0.2 mL) followed by surgical castration (n = 24); (2) saline (1.5 mL) IG and IN (0.2 mL) followed by sham castration (25); (3) lidocaine (20 mg/kg or 1.5 mL) IG followed by surgical castration (24); (4) lidocaine (20 mg/kg or 1.5 mL) IG followed by sham castration (25); (5) FM (2.2 mg/kg) IN followed by surgical castration (25); (6) FM (2.2 mg/kg) IN followed by sham castration (24); (7) lidocaine (20 mg/kg or 1.5 mL) IG and FM (2.2 mg/kg) IN followed by surgical castration (24); and (8) lidocaine (20 mg/kg or 1.5 mL) IG and FM (2.2 mg/kg) IN followed by sham castration (24).

Results: Prostaglandin E2 concentrations did not increase following the castration procedure and were not an effective biomarker of castration inflammation. Piglets that received lidocaine demonstrated no difference in PGE2 levels across all time points. Piglets administered FM had lower PGE2 concentrations at 1 hour and 20 minutes postdrug administration in both the sham and castrated piglets.

Conclusions: Prostaglandin E2 was not an effective biomarker to quantify castration inflammation. Flunixin meglumine was able to reduce PGE2 concentration in piglets regardless of castration procedure, but lidocaine had no impact. Decreased PGE2 levels in FM-treated pigs are likely associated with the drug's ability to mitigate a noncastration-associated inflammatory process occurring independent of the castration procedure.

Clinical relevance: Flunixin meglumine reduced circulating PGE2 concentration in the blood, regardless of the castration procedure, indicating a potential for the drug to mitigate an inflammatory process unrelated to castration.

Objective: To evaluate the effects of topical naltrexone on wound healing in freshwater fish.

Animals: 25 blackbelt cichlids (Vieja maculicauda).

Methods: A randomized, controlled, experimental trial was performed, with each individual serving as its own control. Bilateral 6-mm periepaxial cutaneous wounds were created in the body-wall skin of each fish under anesthesia. Three treatment groups were as follows: topical 0.04% naltrexone in administration vehicle (iLEX ointment; iLEX Health Products) at day 0 only (n = 10), topical 0.04% naltrexone in iLEX every 72 to 96 hours (n = 10), or iLEX only every 72 to 96 hours (n = 5) for 10 total treatments. The contralateral wound was left untreated as a control. Fish were maintained in a common enclosure at 24.7 to 25.4 °C for 35 days. Macroscopic wound assessment and image collection were performed every 72 to 96 hours. On day 35, fish were humanely euthanized, and skin samples were collected for histopathology.

Results: Time to complete visual resolution of wound healing was faster (P = .002) in wounds treated every 72 to 96 hours with topical 0.04% naltrexone in iLEX (day 19.4) compared to untreated wounds (day 23.3). An interaction between treatment and day was observed (P = .002), with fish treated with 0.04% naltrexone in iLEX every 72 to 96 hours having reduced (P < .05) wound area compared to both controls and fish treated with topical 0.04% naltrexone in iLEX once. No significant differences were noted in histologic sections of wound sites examined at day 35.

Clinical relevance: Fish improved earlier postsurgery and time to complete wound resolution was faster in wounds treated with topical 0.04% naltrexone in iLEX every 72 to 96 hours.

Objective: To develop an accessible ruminant immune challenge model for rapid in vivo assessments of feed additives.

Animals: 60 hair-breed ram lambs.

Methods: Sheep were randomly assigned to 1 of 4 treatments: treatment 1, not immunosuppressed, control fed (n = 12); treatment 2, immunosuppressed, supplemented with a yeast and botanical extract (n = 18); treatment 3, immunosuppressed, supplemented with a blend of natural aluminosilicates and yeast components (n = 18); and treatment 4, immunosuppressed, control fed (n = 12). Twice-daily injections of dexamethasone (Dex; 0.1 mg/kg bodyweight, SC) were used to induce immunosuppression throughout the study (from September 25, 2020, to November 2, 2020). All sheep were immunized with keyhole limpet hemocyanin (KLH) on days 0 and 14 and injected with heat-aggregated KLH, ID, to induce a skin induration on day 15. Measurements included body weight (BW), average daily gain (ADG), CBC, and skin induration diameter.

Results: Dex treatment resulted in reduced BW and ADG that was not mitigated by either feed additive. Dex reduced lymphocyte percentage, RBC count, hemoglobin, hematocrit, and skin induration diameter and increased concentrations of granulocytes and granulocyte percentage. Effects on hematocrit, hemoglobin, RBC, and skin induration diameter were mitigated with the addition of feed additives.

Clinical relevance: The described model is a tool to evaluate the ability of feed additives to mitigate the immunosuppressive effects of Dex.

Objective: To investigate thermoregulation, thermal antinociception, food/kaolin intake, fecal output, and behavior following long-acting buprenorphine preparations in rats.

Animals: 8 adult male rats (Rattus norvegicus) were administered long-acting SC buprenorphine (SB; 0.65 mg/kg), transdermal buprenorphine (TB; 10 mg/kg), and controls in a randomized, cross-over design.

Methods: Body temperature, self-injury, sedation, food/kaolin intake, fecal output, and thermal withdrawal latencies were measured 1, 4, 8, 12, 24, 48, and 72 hours posttreatment. Data analysis was performed with mixed linear models.

Results: Self-injury was present between 1 and 12 hours and 4 and 12 hours following TB and SB, respectively; sedation was associated with TB at 12 to 24 hours. Withdrawal latencies were longer in both TB and SB groups than in the control group. Food intake decreased with time in all groups but was significantly lower 24 to 48 hours after TB and 24 to 72 hours after SB versus controls. Kaolin intake decreased from baseline 48 to 72 hours in the control group. Fecal output decreased from baseline 24 to 72 hours in all groups but was significantly lower than controls 24 hours following TB and 24 to 48 hours in SB. Body temperature increased from baseline at 1 hour, 1 to 12 hours, and 1 to 24 hours in the control, TB, and SB groups, respectively, and was significantly higher than the control group 1 to 72 hours following TB and 4 to 24 hours after SB. Transdermal buprenorphine and SB in normal rats produced antinociception, self-injurious behavior, hyperthermia, and decreased food/fecal output.

Clinical relevance: Although these buprenorphine preparations may produce antinociception, untoward effects such as hyperthermia, self-injurious behavior, and reduced food intake/fecal output may be seen.

Objective: To describe changes in circulating hyaluronic acid (HA) concentration, a biomarker of endothelial glycocalyx degradation, after administration of fresh-frozen plasma (FFP) in critically ill dogs.

Animals: 12 client-owned dogs receiving an FFP transfusion due to underlying disease.

Methods: Plasma samples were collected for HA concentration measurement pre-FFP transfusion (T0) and 10 minutes (T10) and 90 minutes (T90) following completion of FFP transfusion of a minimum volume of 7 mL/kg. Hyaluronic acid was also measured in the transfused FFP units following in-house validation of a commercial HA assay on citrate phosphate dextrose-anticoagulated plasma. Potential associations of the difference between pre-FFP and post-FFP HA plasma concentrations with the volume of FFP transfused, the cumulative volume of IV fluids administered during the study period, and the HA concentration in the transfused unit were explored.

Results: Concentrations of HA were not significantly different between pre- and post-FFP transfusion measurements. The volume of FFP transfused, the cumulative volume of other IV fluids administered during the study time, and the concentration of HA in the FFP units had no significant effect on the change in HA concentration following FFP transfusion in this study.

Clinical relevance: This pilot study did not demonstrate an association between FFP administration and changes in plasma HA concentration. The results of this study may serve to help design future research. A commercial assay was validated to measure HA in citrate phosphate dextrose-anticoagulated plasma.