American journal of veterinary research最新文献

Objective: To assess the performance of transpulmonary thermodilution (TPTD) using room-temperature saline (CORT) and waveform-derived continuous CO (CCO) compared with TPTD using iced saline (COICED) as the indicator for measurements of CO in isoflurane-anesthetized dogs.

Methods: 8 Beagles aged 1 to 2 years (7.4 to 11.2 kg) were enrolled in this experimental study from March 21 to 31, 2023. Dogs were anesthetized with 0.01 mg/kg acepromazine, 5 to 6 mg/kg propofol, and isoflurane and were mechanically ventilated. Dogs were instrumented with a central venous catheter and a femoral arterial catheter equipped with a thermistor. The COICED, CORT, and pulse wave-derived CCO values were obtained at baseline, during infusions of phenylephrine and norepinephrine, and during blood withdrawal and replacement. Data were analyzed with a mixed effect model, Bland-Altman plots, and concordance. Percent error was calculated. P < .05 was used for significance.

Results: Data were collected from 8 dogs. Significant effects of time and the interaction of time and method were found. Bland-Altman plots showed negligible bias with limits of agreement between -0.35 and 0.25 L/min for CORT versus COICED and -1.23 and 1.15 L/min for CCO versus COICED. Percent errors were 17.7% and 66.6%, respectively. In the 4-quadrant plots, the concordance rate was 95% and 68% for measurements obtained with CORT and for CCO, respectively.

Conclusions: Transpulmonary thermodilution using room temperature saline was accurate and able to track changes in CO. Continuous CO had a large percent error and low tracking ability.

Clinical relevance: Transpulmonary thermodilution using room temperature saline is reliable for monitoring CO and obviates the need for iced preparations in clinical scenarios.

Objective: Slow hoof growth poses a clinical challenge when hoof wear exceeds natural growth. Many treatment options have been reported without controlled prospective trials. The objective of this study was to evaluate the effect of transdermal CO2 on the rate of growth in treated hooves.

Methods: A prospective, randomized, blinded, crossover study of 14 Warmblood mares. Horses were randomly assigned a number and allocated for treatment of the front feet with room air or CO2 for 30 minutes 3 times per week, and groups were switched after 5 weeks. Hoof growth was measured on the dorsal midline and the quarters of each front foot. The distance from coronary band to lines made on the hoof wall was measured at the beginning, middle, and end of the study. The percentage of change in length at each location relative to baseline was evaluated at 5 weeks and 10 weeks using nonparametric analyses.

Results: All treatments were successfully administered. The left front medial (P = .028) and right front lateral (P = .03) sites of the CO2-treated hooves increased growth compared to the room air group at the 5-week point.

Conclusions: The results of this study suggest that repeated, noninvasive transdermal application of CO2 may accelerate hoof growth in normal horses over a 5-week treatment period.

Clinical relevance: This study suggests that transdermal CO2 may increase the rate of hoof growth in normal horses. The mechanism of action of this treatment is unclear, and further studies are required to fully elucidate the potential effects.

Objective: To explain the relationship between cartilage erosion and medial patellar luxation (MPL) and to identify risk factors in dogs.

Methods: A retrospective review was conducted on 90 dogs (103 stifles) surgically treated for MPL between January 2006 and March 2024. Data collected included signalment, side of operated stifle, patellar luxation grade, symptom duration, and lameness score. Cartilage erosion was evaluated for extent and location on the patella and femoral trochlea. Statistical analyses were conducted to identify risk factors.

Results: The prevalence of cartilage erosion of the patella and femoral trochlea was 47.6% (49/103) and 54.4% (56/103), respectively, increasing with a higher grade of patellar luxation. Lesions were most prevalent in the distolateral patella and proximomedial trochlea, with generalized lesions more prevalent in grade IV. The extent of both lesions was significantly associated with age, patellar luxation grade, and symptom duration, while body weight significantly correlated only with the cartilage erosion of the patella. No significant correlation was observed with sex, side of operated stifle, or lameness score.

Conclusions: Many patients with MPL exhibited cartilage erosion in the patellofemoral joint, likely due to biomechanical mechanisms. Surgery can be indicated for patients with MPL, as it may prevent cartilage erosion while improving patellofemoral alignment and gait. When selecting surgical candidates, it is important to consider risk factors, such as patellar luxation grade, body weight, age, and symptom duration.

Clinical relevance: Early surgical treatment is recommended, especially for dogs with higher body weight and higher grade of MPL, to prevent cartilage erosion and secondary osteoarthritis.

Objective: To compare multiple noninvasive ECG methods in pond sliders based upon repeatability, ability to recognize standard waveforms, and measurability.

Methods: The study was performed from November 2023 through January 2024. Ten healthy adult pond turtles were enrolled in the study. ECG tracings were obtained using 4 previously reported and 1 novel ECG methodology, using adhesive patches applied to the prehumeral fossae and abdominal scutes. The 50 ECG tracings were blinded by method and turtle, randomized for evaluation by 4 observers, and assessed for quality on a scale from 0 to 3.

Results: Interobserver and intraobserver intraclass correlation coefficients for all tracings were 0.84 and 0.97, respectively, indicating an almost perfect agreement. The average score amongst the observers for each tracing was then averaged by method, ranging from 0.875 to 2.15. The novel method demonstrated a collective average of 2.15 and was the highest scoring method for 8 of 10 turtles.

Conclusions: Electrocardiogram utilizing methods that apply adhesive patches to the prehumeral fossae and either the abdominal scutes of the plastron or prefemoral fossae in pond turtles can be performed to produce recognizable waveforms.

Clinical relevance: Diagnostic tools, such as ECGs, are imperative to enhance veterinary care in nonconventional species, particularly with the rising trend of exotic pets worldwide.

Objective: To evaluate sedation and IV xylazine requirements to achieve 45% of baseline head height above ground measurements following oral (PO) administration of 2 trazodone dosages.

Methods: 8 healthy, adult mares of various weights and breeds belonging to a university teaching herd were utilized in a blinded, crossover study design. Horses were randomly assigned to 1 of 3 PO treatments: control (no trazodone), trazodone at 3 mg/kg (low dose [LD]), or trazodone at 6 mg/kg (high dose [HD]). Before treatment, cardiac auscultation, EquiSed sedation score, and head height above ground (HHAG; cm) measurements were performed (baseline) followed by feeding of the treatment mixture. After 120 minutes, sedation score and HHAG were recorded. Xylazine was administered IV (0.25 mg/kg bolus followed by 0.1 mg/kg/min) until HHAG reached 45% of baseline or a total dose of 1 mg/kg was reached. Individual data for xylazine dosage, sedation scores, and HHAG were analyzed using mixed linear models with repeated measures.

Results: Sedation scores were significantly improved (LD, P = .045; HD, P = .01) and HHAG was lowered (LD, P = .045; HD, P = .09) by trazodone administration. Xylazine dose requirements were increased by LD trazodone administration (increase of 0.26 ± 0.26 mg/kg; P = .03) and unchanged by HD (increase of 0.13 ± 0.25 mg/kg; P = .38).

Conclusions: Oral trazodone administration increases quantifiable sedation in horses. Xylazine requirements are significantly increased by LD trazodone administration.

Clinical relevance: Oral administration of LD trazodone may increase xylazine requirements. Further clinical studies are required to fully assess the clinical relevance of this finding on other parameters such as cardiovascular physiology.

Objective: To evaluate if opioid-induced behavioral effects, such as sedation, can be detected using a shuttle box experimental apparatus and whether thermal preference following noxious stimulation using mustard oil is reversed by morphine administration in fish.

Methods: 5 goldfish (Carassius auratus) underwent 2 randomized blinded experimental trials, with a crossover study design. First, opioid effects were tested in a shuttle box without painful stimulus. Fish were injected 5 days apart with butorphanol at 0.4 or 10 mg/kg, morphine at 5 or 10 mg/kg, or saline IM. After 30 minutes, each fish was placed in a shuttle box for 2 hours with a temperature gradient of 26 to 28 °C. Temperature preference, time spent immobile, and swimming velocity were assessed. The second trial consisted of cutaneous noxious stimulation using mustard oil immersion for 5 minutes followed by an assessment of thermal preference for 4 minutes in the shuttle box after either morphine at 10 mg/kg or saline IM injections. Linear mixed models were used to compare treatment groups.

Results: Before noxious stimulation, a low dose of morphine caused sedation compared with control group and high-dose morphine and butorphanol treatments. Immersion in mustard oil caused fish to spend more time in the cold area in the control group. Morphine administration reversed this pattern.

Conclusions: The sedative and analgesic effects of opioids were detected through this model.

Clinical relevance: The shuttle box model could be used to assess the analgesic effects of other opioids in goldfish while reducing biases associated with the sedative and stimulatory effects of these drugs.

Objective: To determine the reproductive effects of feeding spent hemp biomass (SHB) to rams. Several studies suggest cannabidiols negatively affect reproductive characteristics, and the reproductive effects of SHB ingestion have not been investigated in any species. Spent hemp biomass is high in protein and essential fatty acids, indicating a potential use in livestock diets pending studies investigating its safety in animals.

Methods: Polypay rams approximately 6 months old were randomly assigned to 5 feeding trial groups (n = 7/group): either a low or high concentration of SHB in diet for either 4 or 8 weeks plus a control group. Blood samples were collected for hormone assays. At the conclusion of the feeding trial, the testes were removed, and sperm collected directly from the vas deferens were evaluated for motility (total, progressive, and speed), morphology, and concentration. A section from each ram's testes was formalin fixed, paraffin embedded, and subjected to routine immunohistochemistry to determine the expression of fertility-associated proteins deleted in azoospermia-like and Boule, followed by quantitative image analysis.

Results: Rams fed either 10% or 20% SHB for 8 weeks had significantly higher progressive sperm motility compared to controls. There were no significant differences between the treatment and control groups in the other parameters studied. Boule immunoexpression was adversely affected, whereas deleted in azoospermia-like immunoexpression was differentially affected by SHB ingestion.

Conclusion: We conclude that up to 20% of the diet can be fed as SHB to rams for 8 weeks without adversely affecting testicular or sperm function.

Clinical relevance: Supplementing young rams with SHB is unlikely to affect fertility.