Dr Alison Prutton

Objective

To compare synovial concentrations of amikacin following intravenous regional limb perfusion (IVRLP) with two different doses, and to compare their ability to reach target concentrations for bacterial isolates from common orthopedic conditions.

Study Design

Randomized crossover experiment.

Animals

Six adult horses.

Methods

Horses received IVRLP with 2 and 3 g of amikacin in the cephalic vein of alternate limbs (20 minutes tourniquet application and ≥14 days washout period). Amikacin concentrations were quantified in synovial fluid collected from the middle carpal and metacarpophalangeal joints at 25 minutes, and 24, 36, and 48 hours after IVRLP. Minimum inhibitory concentrations (MIC) were determined from equine bacterial isolates and ability to reach target amikacin concentrations were compared.

Results

Overall, middle carpal joint amikacin concentrations were higher following IVRLP with 3 g amikacin compared to 2 g (P=.031), with significant differences at 25 minutes (P=.002) and 24 hours (P=.021). No differences were observed between doses in the metacarpophalangeal joint (P=.267). Target amikacin concentrations for Staphylococcus aureus and coagulase-negative staphylococci were achieved in middle carpal and metacarpophalangeal joints at 25 minutes with both dosages and for Escherichia coli and Actinobacillus spp. in the middle carpal joint at 25 minutes with 3 g. Target concentrations were not achieved for Enterococcus spp, Pseudomonas spp, or Streptococcus equi ssp. zooepidemicus.

Conclusion

A 3 g amikacin dose is not justified in the majority of distal limb injuries, but should be reserved for isolates with an MIC higher than that achievable with a 2 g dose. Daily IVRLP may be necessary based on our results.

OBJECTIVE To investigate the impact of age and inferred prior vaccination history on the persistence of vaccine-induced antibody against rabies in horses.

DESIGN Serologic response evaluation.

ANIMALS 48 horses with an undocumented vaccination history.

PROCEDURES Horses were vaccinated against rabies once. Blood samples were collected prior to vaccination, 3 to 7 weeks after vaccination, and at 6-month intervals for 2 to 3 years. Serum rabies virus–neutralizing antibody (RVNA) values were measured. An RVNA value of ≥ 0.5 U/mL was used to define a predicted protective immune response on the basis of World Health Organization recommendations for humans. Values were compared between horses < 20 and ≥ 20 years of age and between horses inferred to have been previously vaccinated and those inferred to be immunologically naïve.

RESULTS A protective RVNA value (≥ 0.5 U/mL) was maintained for 2 to 3 years in horses inferred to have been previously vaccinated on the basis of prevaccination RVNA values. No significant difference was evident in response to rabies vaccination or duration of protective RVNA values between horses < 20 and ≥ 20 years of age. Seven horses were poor responders to vaccination. Significant differences were identified between horses inferred to have been previously vaccinated and horses inferred to be naïve prior to the study.

CONCLUSIONS AND CLINICAL RELEVANCE A rabies vaccination interval > 1 year may be appropriate for previously vaccinated horses but not for horses vaccinated only once. Additional research is required to confirm this finding and characterize the optimal primary dose series for rabies vaccination.

A 14-year-old Quarter Horse was examined for a draining tract of 8 months’ duration on the right mandible that was non-responsive to antibiotic therapy and surgical therapy. Further investigation and subsequent treatment with sialoendoscopy and ultrasonography were performed to relieve an obstruction of plant awns in the mandibular salivary duct.

This study aimed to assess the effect of lateral heel studs on foot–ground interaction in the horse by quantifying foot slip during stance whilst cantering on a grass surface. It was hypothesised that using studs would decrease foot slip distance on the ground conditions tested. Nine horses were ridden with and without a stud placed laterally in the shoe of each of the 4 feet. High speed video-analysis was used to track hoof markers and to provide data quantifying foot slip distance, slip duration and stance duration. Using studs resulted in a significant decrease in foot slip distance in all four limbs (all P values < 0.004). The magnitude of the difference in slip distance with and without studs was greatest in the trailing limbs.

The results supported the hypothesis that using studs will decrease foot slip distance in horses cantering on a grass surface, and additionally, highlights that stud efficacy may vary between limbs. The decrease in slip distance with studs demonstrated increased traction and a more stable foot–ground interaction, although this may cause a concomitant increase in the required energy dissipation, either within the limb or via surface deformation. The effect of repetitive usage of studs in the aetiology of musculoskeletal conditions should therefore be investigated further.

Simulation in veterinary education is an important means of providing a safe, welfare-friendly way for students to hone their skills prior to performing procedures on live animals. Students may not get many chances to practice passing a nasogastric tube and checking for reflux in live horses during clinical rotations and extra-mural studies. A low-cost equine nasogastric intubation model was created at the University of Surrey, allowing students to practice passing a tube and checking for reflux. Thirty-two equine veterinarians evaluated the model for realism, and its potential usefulness in teaching. Veterinarians found the model to be realistic, supported its use as a teaching aid, and provided helpful feedback for possible improvements. In addition, 83 year 4 veterinary students rated their level of confidence before and after using the model for nine specific aspects of nasogastric intubation. Students showed significantly increased confidence levels in all nine aspects after using the model, and reported that they appreciated being able to practice the skill in a safe environment prior to performing it on a live horse. The results of this study suggest that both clinicians and students considered that this model has educational value, which supports its use for training veterinary students prior to clinical placements. The model provides an affordable, robust educational aid that can be used in clinical skills teaching, increases student confidence, and allows students to practice the skill repeatedly.

Background

Recruitment and retention of equine veterinarians presents an ongoing challenge for employers. Recent research has highlighted factors that contribute to attrition across the profession, but further understanding of the specific challenges faced in the equine sector is needed. This study builds on existing research by exploring the relative impact of different factors on veterinarians’ decisions to leave equine clinical practice.

Methods

Veterinarians who had left equine clinical practice in the UK within the previous 10 years were invited to participate in an anonymous online survey. The participants were asked about the extent to which various factors influenced their decision to leave, and about the kind of job roles they were pursuing instead.

Results

Both work-related and non-work-related (personal) factors had an important impact on the decision to leave equine clinical practice, and there was often interplay between the two. The three factors with the most significant impact were work related. These were ‘excessive workload/unsustainable work schedules’, ‘the requirement for out-of-hours work’ and ‘lack of opportunity for professional growth’. The most important non-work-related factors were ‘lack of personal time’ and ‘alternative professional interests’. In comparison to existing research from the entire veterinary profession, the requirement for out-of-hours work and a lack of opportunity for professional growth appeared to be particularly relevant for the equine sector.

Limitations

The number of participants was relatively small (n = 33), and limited demographic data were collected; therefore, the results cannot be extrapolated to different demographic groups.

Conclusion

This information may help guide decision making to improve retention of a resilient equine veterinary workforce.

Horse ‘vetting’ has been around for centuries, and as a result, many veterinary conditions, anatomical and other terms have colloquial or common language names. This language may seem like second nature to those of you that have experience of working with horses or have grown up immersed in the equine industry, but it is less obvious if you’re newer to the ‘horse world’. 

The use of industry-specific language will vary between equestrian disciplines and sports, from racing to rodeos…and everything in between! There are also regional and international differences in terminology. However, wherever you are in the world, horse owners and horse-lovers often have a wealth of knowledge about their chosen sport or discipline and generally love to talk about horses! This guide aims to help veterinary students to become familiar with the kinds of terms you might get used to hearing and using when conversing with equine veterinary clients.