Abstract
OBJECTIVE
To determine the effect of levomethadone/fenpipramide and metamizole alone and in combination on acute nociception.
METHODS
8 healthy, adult Beagles were used in 2 separate randomized, complete crossover, experimental trials (threshold testing and determination of minimal alveolar concentration [MAC]) with masked observers. In both trials, treatments were 0.2 mg·kg−1 levomethadone/fenpipramide (L), 75 mg·kg−1 metamizole (M), or their combination (LM). In conscious dogs, mechanical thresholds were determined using constantly rising force. Thermal thresholds were measured via ramped contact heat. The MAC of sevoflurane was determined using the bracketing method with electrical stimulus (50 V, 50 Hz, 10 ms) before and 1 and 4 hours after treatment.
RESULTS
Mechanical thresholds in L and LM were significantly increased above baseline (BL) for 165 minutes and above M for 135 minutes. Percent thermal threshold excursion significantly increased above BL in L for 75 minutes and in LM for 135 minutes. In L and LM, the percent thermal threshold excursion was significantly higher than in M from 15 to 75 or 135 minutes, respectively. In L and LM, the MAC of sevoflurane was significantly reduced at 1 hour compared to BL and M.
CONCLUSION
Duration but not the magnitude of thermal antinociception of levomethadone/fenpipramide was increased by metamizole. Mechanical antinociception in awake dogs and anesthetic-sparing effects of levomethadone/fenpipramide were not altered.
CLINICAL RELEVANCE
Coadministration of levomethadone/fenpipramide and metamizole to increase antinociception is not justified.
Abstract
OBJECTIVE
To determine the normal fecal microbiome of healthy rabbits in comparison to rabbits with gastrointestinal (GI) disease. Next-generation DNA sequencing was used to identify the primary bacteria and fungi in the microbiome.
METHODS
Fecal pellets from 25 clinically healthy rabbits and 25 rabbits experiencing GI disease were collected. Next-generation DNA sequencing was performed targeting the ITS-2 region for mycobiome, and the V1–V3 region of the 16S rRNA for bacteriome analysis. ITS-2 stands for internal transcribed spacer 2, a region of DNA in fungi that is used to identify and classify species.
RESULTS
In healthy rabbit feces, Bacteroidales sp, Odoribacter sp, Paraprevotella xylaniphila, Lachnospiraceae sp, Papillibacter sp, Akkermansia sp, and Ruminococcus sp were noted to be more prevalent. Comparatively, Lachnoclostridium sp, Anaerotruncus sp, Subdoligranulum sp, and B uniformis were found in greater abundance in rabbits with GI disease. Only 1 fungal species, Malassezia restricta, was significantly enriched in the GI disease group.
CONCLUSIONS
Next-generation DNA sequencing technology can be used to evaluate the microbiome of the rabbit GI tract through fecal material and can provide a clinically accessible testing method for veterinarians.
CLINICAL RELEVANCE
Numerous bacteria and fungi in the fecal samples of healthy rabbits were identified that could be considered markers of gastrointestinal health; similarly, specific bacteria and fungi were noted in greater abundance in rabbits with GI disease, which should be further investigated for their importance in causing, contributing to, or as the result of clinical disease. These findings support the use of next-generation DNA sequencing in order to diversify our understanding of the microbiome of rabbit feces, aid in clinical diagnosis, and provide support for the need for more specific probiotic supplements for rabbits.
Abstract
OBJECTIVE
Evaluate the incidence of Borrelia burgdorferi in cases of equine nuchal bursitis (NB) and investigate the relationship between elevated serum outer surface protein A (OspA) antibodies and the molecular identification of B burgdorferi in bursal tissue or synovial fluid. Additionally, describe clinical cases and compare the histologic changes in NB with and without detection of B burgdorferi.
METHODS
This was a retrospective multicenter cohort study (2013 to 2022). Medical records from horses with a diagnosis of NB and B burgdorferi PCR testing on NB tissue or synovial fluid were reviewed. The study population included 11 horses with a postmortem diagnosis of NB, 19 horses from the northeastern US with an antemortem diagnosis of B burgdorferi PCR–positive NB, and 15 healthy controls without evidence of NB and unvaccinated for B burgdorferi. Where serum was available, Lyme multiplex assay results were compared with controls and ELISAs targeting individual B burgdorferi antigens were performed. Histologic findings in nuchal bursa tissue were compared between NB cases with and without B burgdorferi PCR detection.
RESULTS
Serum OspA antibody values in B burgdorferi–positive NB cases (n = 13) were significantly elevated (P < .001) compared to controls (15), and OspA was the predominant antigen detected by ELISA (8). Histopathology did not vary between NB cases with (n = 9) and without (6) B burgdorferi PCR detection.
CONCLUSIONS
The presence of B burgdorferi in the nuchal bursa of horses is associated with increased serum OspA antibodies.
CLINICAL RELEVANCE
The role of B burgdorferi in equine NB may be underestimated, and targeted therapy requires investigation.
Abstract
OBJECTIVE
To determine (1) the dose of liposomal bupivacaine (LB) to eliminate grade 2 of 5 lameness, the (2) duration of analgesia of LB versus bupivacaine hydrochloride (BH), and (3) LB pharmacokinetics versus BH.
METHODS
A reversible lameness model was validated in conditioned Thoroughbred horses (n = 12), aged 3 to 10 years. A dose-response trial compared subjective and objective lameness following abaxial sesamoid block with 25 mg BH/nerve or 30, 60, or 133 mg LB/nerve (n = 3/group). The LB dose that eliminated lameness and reduced lameness for the longest was used for blinded, randomized, crossover pharmacokinetic/pharmacodynamic trials (n = 12/group). Data were analyzed using a paired t test or Wilcoxon signed-rank test, P < .05.
RESULTS
The 133-mg/nerve dose of LB eliminated lameness in 3 of 3 horses in the dose-response trial, and lameness returned at 6, 36, and 72 hours. In the pharmacokinetic/pharmacodynamic trials, time to return of lameness greater than or equal to starting lameness was longer for LB compared to BH on subjective (LB, 12 hours, 4 to 24 hours; BH, 4 hours, 4 to 12 hours) and objective (LB, 12 hours, 4 to 24 hours; BH, 4 hours, 2 to 6 hours) evaluations. The terminal half-life was not different between formulations (LB, 17.8 hours ± 10.1; BH, 12.4 hours ± 6.3); however, LB had increased area under the concentration-versus-time curve from time 0 to infinity (LB, 388 ng·h/mL ± 117; BH, 63 ng·h/mL ± 18) and mean residence time (LB, 17.6 hours ± 2.4; BH, 3.9 hours ± 1.6).
CONCLUSIONS
Liposomal bupivacaine analgesia duration was greater than BH, but the median time until lameness returned was only 12 hours. Bupivacaine is quantifiable in serum and urine beyond loss of clinical effect.
CLINICAL RELEVANCE
A single, high-dose injection of LB is not effective for providing perineural analgesia over several days. Bupivacaine is detectable after the effect of the drug has worn off.
Abstract
Small animal antimicrobial stewardship (AS) is emerging as a priority area in the global battle against antimicrobial resistance. Veterinary practices have limited support for implementation of AS programs, and even within veterinary schools, efforts are largely siloed and often limited in scope. Increased collaboration is needed to support and unify AS and infection prevention and control efforts, and to identify priorities for continued research. To address this, a 2-day in-person small animal AS workshop was held in August 2023. Delegates representing 23 US veterinary schools and 4 corporations/government agencies gathered for a series of lightning talks and focused group discussions in 3 domains: implementation of clinical AS programs, research opportunities and needs, and education. The workshop’s goal was to identify and propose solutions for AS challenges. Meeting discussion identified a lack of resources and training as the greatest barriers to hospital AS program advancement and suggested creating standards for AS programs and a road map to support program development. Assessing antimicrobial treatment effects and performing studies to establish necessary treatment durations were considered the highest research priorities. Integrated educational practices were recommended to support unified messaging of AS concepts between preclinical and clinical training. The development of strategies to implement these suggestions was delegated to working groups with a goal to continue meeting biennially as a large group. Sharing news of these efforts is considered integral to heightening awareness and promoting implementation of AS practices moving forward in academic, specialty, and primary care settings.