American journal of veterinary research最新文献

Objective: To determine the feasibility of catheterizing the portal vein to obtain serial portal vein blood samples in steers. We hypothesized that the portal vein catheterization would be a successful continuous sampling technique with minimal adverse effects in steers.

Methods: 2 groups of steers were used: a pilot group (n = 2) and experimental group (n = 6). In both groups, steers were sedated with xylazine. The right rib spaces were clipped and aseptically prepped. The portal vein was visualized via ultrasound, and a 14-gauge catheter was placed percutaneously and advanced into the portal vein. A guide wire was passed through the catheter, followed by a tissue dilator and then a vascular balloon catheter. In the pilot group, blood chemistries were performed prior to portal vein catheterization and then again once the catheter was placed (with samples from both the jugular vein and portal catheter). The liver was also examined at necropsy for any gross lesions in both groups.

Results: All steers tolerated the portal vein catheters well, with the catheters lasting for the full length of the study period (7 days). The only observed adverse reaction was a superficial abscess at the catheter site (n = 3). On necropsy, 1 liver had gross discoloration, but no other abnormalities were noted. There were no significant changes in biochemistry profiles before or after portal vein catheterization.

Conclusions: Portal vein catheterization is a novel and feasible serial sampling technique of the portal vein.

Clinical relevance: This technique can be used in future pharmacokinetic, nutrition, metabolism, or toxicity studies.

Objective: To assess the pharmacokinetics and sedative effects of a single administration of oral gabapentin in African cheetahs (Acinonyx jubatus) at 2 different dosages.

Methods: Adult cheetahs (n = 16) located at 3 different zoological institutions were prospectively enrolled to receive single doses of gabapentin administered at 2 different dosages (10 mg/kg and 20 mg/kg). Venipuncture was performed under behavioral restraint at predetermined time points over a 24-hour period using a sparse sampling model. Plasma concentrations of gabapentin were determined using high-performance liquid chromatography. A modified domestic felid sedation scoring system was used to assess animals at each time point by 3 masked scorers, and sedation scores were compared between time points.

Results: Mean ± SE maximal plasma concentrations were 24.0 ± 12.8 μg/mL and 31.4 ± 8.57 μg/mL for the 10- and 20-mg/kg dosages, respectively. For both dosages, concentrations remained elevated at the final collection time point of 24 hours (2.39 ± 1.97 and 3.93 ± 3.09 μg/mL for 10 and 20 mg/kg, respectively). Mild sedation was achieved for both doses up to 24 hours postadministration, with no significant differences between dosages.

Conclusions: Gabapentin was well absorbed following oral administration, and concentrations remained elevated 24 hours postadministration. Gabapentin produces mild sedation at 10 or 20 mg/kg for up to 24 hours.

Clinical relevance: Gabapentin given to cheetahs at these dosages is a useful tool for improving patient welfare due to its mild sedative effects over a clinically relevant time period.

Objective: To describe the presentation, clinical findings, diagnosis, treatment, and outcome of cases of trismus (lockjaw) in cold-stunned sea turtles.

Animals: 4 Kemp's ridley (Lepidochelys kempii) and 1 loggerhead (Caretta caretta) sea turtle.

Methods: Cold-stunned sea turtles that presented with difficulty or inability to open their jaw between 2009 and 2023 were included. Information retrieved from medical records included signalment, physical exam findings, diagnostic information, definitive diagnosis via either advanced imaging or histopathology, treatment, and clinical outcome.

Results: Turtles presented between 4 and 48 days into rehabilitation. Three were diagnosed by advanced imaging (CT or MRI), and 2 were diagnosed based on clinical signs and postmortem histopathology. Treatment was multimodal and consisted of antibiotics (5/5), nonsteroidal anti-inflammatories (5/5), vitamin E (3/5), intralesional steroid therapy (3/5), acupuncture (3/5), antifungals (2/5), anti-inflammatory parenteral steroids (2/5), physical therapy (2/5), therapeutic laser (2/5), and supportive feeding via either total parenteral nutrition (1/5), or tube feedings (2/5). Two animals were released, 2 died naturally, and 1 was euthanized.

Clinical relevance: Trismus (lockjaw) is an uncommon finding in stranded cold-stunned sea turtles that can have a significant impact on animal welfare if not diagnosed and treated. This report describes the condition to aid clinical case management and resource allocation in rehabilitation facilities.

Objective: To evaluate a predictive model's ability to determine cattle mortality following first and second treatment for bovine respiratory disease and to understand the differences in net returns comparing predictive models to the status quo.

Methods: 2 boosted decision tree models were constructed, 1 using data known at first treatment and 1 with data known at second treatment. Then, the economic impact of each outcome (true positive, true negative, false positive, and false negative) was estimated using various market values to determine the net return per head of using the predictive model to determine which animals should be culled at treatment. This was compared to the status quo to determine the difference in net return.

Results: The models constructed for the prediction of mortality performed with moderate accuracy (areas under the curve > 0.7). The economic analysis found that the models at a high specificity (> 90%) could generate a positive net return in comparison to status quo.

Conclusions: This study showed that predictive models may be a useful tool to make culling decisions and could result in positive net returns.

Clinical relevance: Bovine respiratory disease is the costliest health condition experienced by cattle on feed. Feedyard record-keeping systems generate vast amounts of data that could be used in predictive models to make management decisions. It is essential to understand the accuracy of predictions made via machine learning. However, the economic impact of implementing predictive models in a feedyard will influence adoption.

Objective: The objective of this study was to analyze the use of rebound tonometry, as a noninvasive diagnostic tool, in arachnids.

Methods: 5 juvenile (yearling) female and 1 juvenile male curlyhair tarantulas (Tliltocatl albopilosus, previously Brachypelma albopilosum) were used to track estimated ventral opisthosoma pressures over a 9-month period of time. Younger, growing animals were selected as they are more likely than adults to go through multiple molts throughout the 9 months of the study length. An iCare TONOVET TV01 rebound tonometer was used to measure the estimated ventral opisthosoma pressures of the spiders. Measurements were obtained from the ventral opisthosoma, 1 of the thinnest areas of exocuticle throughout the body. Readings were obtained once per week from the ventral opisthosoma for the first 2 months, then once every 2 weeks for 1 month, then back to once per week for the remainder of the study. Additional measurements were obtained following each ecdysis, after a 2% body weight sampling of hemolymph, and at the end of the study to evaluate readings in response to induction of general anesthesia with 5% isoflurane gas and oxygen flow at 2 L/min for 10 minutes.

Results: The average of all estimated ventral opisthosoma pressure when spiders were not in molt was 26.19 mm Hg (SD, 3.54), with a statistically significant decrease postmolt to an average of 15.31 mm Hg (SD, 3.81), followed by a gradual increase back to premolt pressures over a 3-week period with an average of 22 days (SD, 1.93). Estimated ventral opisthosoma pressures decreased post hemolymph removal. There is not sufficient evidence that estimated ventral opisthosoma pressures changed over time following the anesthesia.

Clinical relevance: This study demonstrates that tonometry can be used to generally assess the estimated ventral opisthosoma pressure, which could correlate with where a spider is in an ecdysis cycle.

Objective: Upper respiratory infections are a frequent problem in pet rabbits and rodents, and Mycoplasma pulmonis is 1 of the most common causes of respiratory infections in pet rats. M pulmonis was detected in 1967 in laboratory rabbits via culture of the nares and oropharynx, but overall, Mycoplasma is not commonly identified in the upper airway of rabbits. The objective of this study was to compare the prevalence of Mycoplasma sp detection via next-generation DNA sequencing on nasal swabs obtained from healthy and unhealthy rabbits.

Methods: The results of nasal swabs from both healthy and unhealthy rabbits submitted for next-generation DNA sequencing from January 2022 to February 2023 were reviewed. Data gathered included signalment, whether or not Mycoplasma sp was detected, and the cell count and relative predominance of Mycoplasma sp compared to other organisms.

Results: 91 rabbits met the inclusion criteria, of which 49 were healthy and 42 were unhealthy. Overall, 52 of 91 (57.1%) rabbits were positive and 39 of 91 (42.8%) were negative for Mycoplasma sp. Mycoplasma positivity was significantly (P < .001) more common in healthy rabbits (37/49 [75.5%]) compared to unhealthy rabbits (15/42 [35.7%]).

Clinical relevance: The fact that Mycoplasma positivity was common in both groups of rabbits, and particularly common in rabbits without upper respiratory signs, suggests that Mycoplasma may be normal nasal flora in rabbits. Further research is needed to determine whether Mycoplasma could function as an opportunistic pathogen in rabbits.

Objective: To investigate whether a humeral intracondylar fissure (HIF) alters bone strain in the French Bulldog humerus, we developed a quantitative CT-based 3-D finite element (FE) model for virtual mechanical testing. We hypothesized that higher strains would be seen in the intracondylar region and lateral epicondylar crest if there was a HIF.

Methods: Patient CT scans from 3 (n = 3) French Bulldogs were selected. Dog 1 had a closed distal physis and no HIF. Dog 2 had an open distal humeral physis but no HIF. Dog 3 had an open distal physis and a HIF. A 3-D FE model was built for FE analysis, and pressure was applied to the humerus over the region that contacts the radial head.

Results: The maximum principal bone strain patterns differed in each of the models. A path of strain concentration mimicking the typical pattern of a lateral condylar fracture was only found in dog 3. Maximum principal strain exceeded 1% in parts of the lateral epicondylar crest in all 3 dogs.

Conclusions: We developed a patient-specific, quantitative CT-based 3-D FE model for virtual mechanical testing. We accepted our hypothesis. Strain concentration occurred in the intracondylar region and along the lateral epicondylar crest only when a HIF was present.

Clinical relevance: The presence of a HIF in French Bulldogs elevates maximum principal bone strain in this region and alters its path in an FE model, which suggests an increased risk of a lateral humeral condylar fracture.

Background: Urinary acidification with ammonium chloride (AC) for urolith dissolution is a common treatment for goats with urolithiasis. Studies have reported increased fractional excretion of calcium (FECa) following AC administration, which could increase calcium-based urolithiasis. D,L methionine (MET) may result in similar acidification with less calcium excretion.

Objective: To compare the effects of orally administered MET and AC on urine and blood pH, FECa, and blood HCO3- concentrations in male goats.

Methods: Prospective, randomized, crossover study. 12 healthy, 5-to-6-month-old Boer-cross wethers were administered 200 mg/kg of AC or MET orally for 14 days with a 7-day washout period between trials. Venous blood and urine samples were collected every 2 days. The effects of treatment and treatment day on urine and blood pH, HCO3-, and FECa were assessed using linear mixed models.

Results: Ammonium chloride and MET lowered least squares means (LSM) urine pH on day 6 (LSM, 7.49; 95% CI, 6.44 to 8.54), 8 (LSM, 7.78; 95% CI, 6.73 to 8.83), and 10 (LSM, 7.53; 95% CI, 6.49 to 8.58) when compared to day 0 (LSM, 8.23; 95% CI, 7.18 to 9.28). Some goats' urine indicated acidification (pH < 7.0) in the first phase of the trial; however, for the entire trial, a significant treatment effect was not detected on urine pH, blood pH, blood HCO3- or log10 FECa.

Clinical relevance: Ammonium chloride and MET acidified urine of some goats. Dietary cation-anion difference should be considered when treating healthy goats to acidify their urine.