Royal Veterinary College Research Articles

Accuracy and Complication Rates of Maxillary Nerve Blocks: A Comparison of Techniques Using Surface Landmarks, Ultrasound and GPS‐Guidance

Reasons for performing studyPerineural analgesia of the equine maxillary nerve is used for diagnostic and surgical procedures. Little data exists to evaluate accuracy and complication rates with current techniques.ObjectivesThis study compared 2 previously described approaches to maxillary nerve analgesia, and a novel needle guidance positioning system (SonixGPS™, Ultrasonix Medical Corporation, Richmond, British Columbia, Canada), assessing relative accuracy and complication rates of each method when performed by inexperienced operators.Study designCadaver study.MethodsClinical veterinary students performed surface landmark, ultrasound and GPS guided contrast injections, to simulate maxillary nerve blocks in 38 equine cadaver heads. Computed tomography was then used to assess accuracy (successful deposition of contrast in contact with the maxillary nerve), and complication rate (contrast identified within surrounding vasculature or periocular structures), associated with each method.ResultsPerineural injection of contrast around the maxillary nerve was attempted 76 times, with an overall success rate of 65.8% (50/76), and complication rate of 53.9% (41/76). Success rates were 50% (13/26) with surface landmark, 65.4% (17/26) with ultrasound and 83.3% (20/24) with GPS guided approaches (Fisher's exact P = 0.046). No significant difference in complication rate was found between the 3 methods.ConclusionsUltrasound guided maxillary nerve blocks are significantly more accurate than surface landmark approaches when performed by inexperienced operators, and best success rates are achieved with GPS needle guidance. All 3 methods were equivalent in terms of complication rates when performed in cadavers.Ethical animal research: This study was authorised by the Ethics and Welfare Committee of the Royal Veterinary College. The study was performed on material obtained from abattoirs. Source of funding: Royal Veterinary College. Competing interests: None declared. Acknowledgements: We thank the technical teams of the Equine Referral Hospital Diagnostic Imaging and Pathology departments and the clinical veterinary students.

Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015.

Training and rehabilitation techniques which improve core muscle strength are beneficial for improvement of dynamic stability of the equine vertebral column. The Equiband™ system, consisting of resistance bands attached to a customised saddle pad, is suggested to provide constant proprioceptive feedback during motion to encourage recruitment of abdominal and hindquarter musculature. To quantify the effect of the Equiband™ system on back kinematics and movement symmetry. Longitudinal intervention study. Quantitative analysis of back movement and gait symmetry before/after a 4-week exercise programme. Inertial sensor data was collected from 7 horses at Weeks 0 and 4 of a fixed exercise protocol. Analysis with and without the Equiband™ system was completed at trot in hand on a hard surface, and for both reins on the lunge on a soft surface. Six back kinematic and 3 movement symmetry parameters were calculated according to published methods. Movement symmetry values were side-corrected to allow comparison between reins on the lunge. A mixed model (P<0.05) evaluated the effects of the Equiband™ system over time, and trotting direction on back kinematic and movement symmetry parameters. The Equiband™ system significantly reduced (all P<0.02) roll, pitch and mediolateral displacement in the cranial-mid thoracic region. Across all horses, back displacement and range of motion values were significantly greater (P<0.01) on the lunge than in a straight line, movement symmetry was consistent with having corrected all horses to be left-sided. Preliminary results suggest the Equiband™ system may aid dynamic stabilisation of the vertebral column. Ethical animal research: This study was authorised by the Ethics and Welfare Committee of the Royal Veterinary College, London (URN Approval Number 1238). Written consent was obtained from the owner/keeper of each animal. Royal Veterinary College. Competing interests: N.C. Stubbs and N. Rombach developed the Equiband™ system. The remaining authors have no competing interests.

Preliminary results of a prospective study of inter- and intra-user variability of the Royal Veterinary College corneal clarity score (RVC-CCS) for use in veterinary practice.

To introduce a new corneal clarity score for use in small animals and describe its inter- and intra-user variability. Twelve dogs and two cats with corneal abnormalities and five dogs with healthy corneas. Four examiners scored every patient twice and never consecutively, focusing on the central cornea. The peripheral cornea was scored separately. The following scoring system was used to describe corneal clarity: G0: no fundus reflection is visible on retroillumination (RI) using a head-mounted indirect ophthalmoscope. G1: a fundus reflection is visible with RI. G2: a 0.1-mm diameter light beam is visible on the anterior surface of the iris and/or lens. G3: gross fundic features are visible when viewed with indirect ophthalmoscopy (IO) using a head-mounted indirect ophthalmoscope and a hand-held 30D lens, although fine details are not clear. G4: fine details of the fundic features are clearly visible with IO. The minimum grades given were analyzed for inter- and intra-user variability with kappa analysis. Intra- and interuser variability of the central corneal clarity ranged from 0.78 to 0.96, showing substantial to almost perfect reproducibility, and from 0.66 to 0.91, showing substantial to almost perfect reliability, respectively. Intra- and interuser variability of the peripheral cornea ranged from 0.83 to 0.95, showing almost perfect agreement, and from 0.53 to 0.91, showing moderate to almost perfect agreement. The RVC-CCS is well suited to assess and monitor central corneal clarity in small animals and to compare outcomes between studies and different surgeons.

Intercalating in global health.

After finishing her third year of veterinary studies at the Royal Veterinary College, Helena Diffey decided to intercalate in global health at Imperial College, London. She explains why global health needs more vets to get involved

Building practice-based research in the UK

IN recent years, the opportunities from veterinary research that uses electronic patient record (EPR) data have been increasingly recognised and, especially in the UK, application of these methods is now...

Bridging the gap between school and university.

Emily Stacey is a third-year student at the Royal Veterinary College, and is one of a group of students that has developed an online course to help new students familiarise themselves with the topics they will study and the most useful ways to study them.

Characteristics of sheep flocks affected by Streptococcus dysgalactiae arthritis

Veterinary RecordVolume 176, Issue 17 p. 435-435 Research Characteristics of sheep flocks affected by Streptococcus dysgalactiae arthritis S.-J. Rutherford BSc, PhD, S.-J. Rutherford BSc, PhD Department of Veterinary Clinical Sciences,...

Responses to successive anti-epileptic drugs in canine idiopathic epilepsy

Veterinary RecordVolume 176, Issue 8 p. 203-203 Research Responses to successive anti-epileptic drugs in canine idiopathic epilepsy R. M. A. Packer BSc (Hons) PhD, R. M. A. Packer BSc (Hons)...

The further away they are: creative approaches to recording bird flight paths

Seeking to model the flight paths of birds as solid objects, this artistic research and development project makes use of digital data collection, computer modelling software and 3-D printing. The project tests notions of objectivity in observation. Eschewing imaginative interpretations of flight, I aspire to allow birds to transcribe their own movements with minimal human intervention. The enquiry began with a drawing process whereby flights were traced by hand on window panes, as they occurred. Subsequent work with the Structure & Motion Lab of the Royal Veterinary College has drawn on high-resolution data from free-flying birds carrying lightweight data loggers. The resulting digital models and 3-D printed models describe short bursts of flight with considerable accuracy. At the same time, the process highlights the impossibility of absolute knowledge and leads to consideration of the need to acknowledge subjectivity – and embrace reciprocity – in observing and recording the natural world.

Debunking the myths around expert witnesses.

The expert witness is a well known legal role, which conjures up images of a glowering judge and fierce cross-examination by a Rumpole of the Bailey-style barrister. Nick Deal is a barrister who works for Bond Solon, a company that provides training for expert witnesses. Here, he considers some of the points raised during a course for pathologists at the Royal Veterinary College.

Achieving uterine auto-transplantation in a sheep model using iliac vessel anastomosis: a short-term viability study.

To investigate, develop and evaluate anatomical, surgical and anastomotic aspects necessary for a successful uterine transplant in a large-animal model. Sheep model; longitudinal study involving five ewes. Royal Veterinary College, London, UK. Five ewes of proven fertility. The uterine allograft along with the internal iliacs, and uterine arterial and venous tree all intact were harvested en bloc. An end-to-side anastomosis was performed between the external iliac vessels and the internal iliac vessels of the graft using 6-0 polypropylene. Successful reperfusion of the graft was initially judged by the color shift of the uterus during reperfusion. Blood flow past the venous and arterial anastomotic sites was also ensured by visual inspection, together with pulse oximetry and multispectral imaging. Operative details (retrieval, ischemic, clamping, reperfusion and recipient hysterectomy duration); physiological profiles; gross morphology and histopathology. Five autotransplants were performed. One procedure was abandoned because of the inappropriate size of sheep model. Another procedure was halted because the animal suffered from respiratory failure in the immediate intra-operative period. Three transplants were completed. In those, at least two of four possible anastomoses were finished and the grafted uteri demonstrated immediate perfusion and appropriate viability 45 min post-operatively. Internal to external iliac vessel anastomoses are an acceptable surgical technique that should be applied in a human model to ensure adequate subsequent uterine perfusion.

Support for sepsis research

PetSavers funding was awarded to Daniel Chan and Ronald Li at The Royal Veterinary College to evaluate platelet function and viscoelestic haemostatic parameters in dogs with septic peritonitis.

No vet is ‘just a general practitioner’

quality continuing professional development (CPD) being offered to veterinary GPs, should we just accept this training and move on, or use it to stimulate our own interest in contributing to the profession? First-opinion practice has altered rapidly over the last 20–30 years; practices were often the epitome of one-stop shops and referral was less common, and the senior partners in practice were the tutors for their assistants. Where the British Veterinary Association and British Small Animal Veterinary Association (BSAVA) congresses were the only regular large meetings, there are now many regional congresses. CPD was to a large extent left to a vet’s conscience, but we are moving towards a much more formal requirement; the Professional Development Phase for new graduates is one such initiative. While the nominal CPD requirement of 105 hours over three years is not yet strictly compulsory, there are movements toward such an obligation. Already, we must demonstrate our commitment to CPD for our practices to achieve a pass in the Practice Standards Scheme, or, if we wish to further our careers, by taking a certificate. There is a positive view of the current situation for vets in general practice. The encouragement to undertake further qualifications, whether following the Cert AVP route, the BSAVA’s PgCert qualification, or the accreditation offered via other CPD providers ensures that we continue the habit of learning, and expand our skill sets. GP vets are now encouraged to publish more case histories in established journals. Companion animal is always happy to consider submissions from our readers; there is a good chance of acceptance, and even if unsuccessful, the peer review process will help potential contributors to ensure the quality of their work. Research in practice is also encouraged. GPs have access to field data that researchers in academic institutions yearn to achieve. This is recognised by initiatives such as VetCompass led by the Royal Veterinary College, which makes use of the data we collect on practice management systems by standardising the recording of diagnoses and so allowing epidemiological studies. Clinical governance and evidence-based medicine are phrases currently in vogue. These concepts rely on analysis of data generated in the practice environment, and on reflection on, and consideration of, that data. A surprising amount of advice that we are expected to provide on common conditions or situations will vary wildly from practice to practice. As modern vets it is our responsibility to be questioning and to want evidence where we can find it. We can, and should, be part of that evidence-gathering process. Vets in first-opinion practice have the opportunity to contribute to furthering our knowledge by conducting research or by auditing diagnoses and treatments, and, using consistent recording, making essential data available to researchers. No vet should consider themselves ‘just a GP’. CA No vet is ‘just a general practitioner’

Seeking surgical experience abroad.

While looking for an EMS placement that would offer some surgical experience, Lillian Cousto, a final‐year student at the Royal Veterinary College, stumbled on the opportunity to be involved in a spay and neuter externship offered by Mississippi State University College of Veterinary Medicine in the USA

Running birds prioritise safety on uneven terrain

Anyone who does cross-country running knows how uneven the real world is, and moving animals have to constantly negotiate bumps and obstacles in their surroundings. But how does size affect the strategy that animals use when encountering objects that impede progress, and which selective pressures have driven the strategies that they use for negotiating these obstacles? Monica Daley from the Royal Veterinary College, UK, explains that an animal's posture could dramatically affect how it manoeuvres across uneven terrain. Small animals that stand with a crouched posture could use a completely different strategy from large upright animals, and Daley wondered which physical factors have driven differently sized animals to select the strategy that works best for them. Explaining that ground-dwelling birds span a mind-boggling range of sizes from heavy weight ostriches down to dainty crouched quail, Daley and her student Aleksandra Birn-Jeffrey decided to find out more about the strategies that birds ranging in size from 0.2 kg up to 117 kg use when running over a step (p. 3786).However, sourcing many of the animals in the UK, some of which are native to the USA, was trickier than Daley had anticipated. She also recalls that working with the ostriches was particularly challenging. ‘Ola [Birn-Jeffrey] hand-raised these ostriches for 2 years so that they were imprinted on humans so that they could be handled easily and weren't as dangerous’, she says.Birn-Jeffrey and Yvonne Blum then filmed the birds as they ran over steps that ranged in size from 0.1 to 0.5 times the length of their leg, and also measured the forces exerted by the birds to find out how their bodies moved as they crossed the obstacle. However, after 4 years of bird rearing, and data collection and analysis, Birn-Jeffrey discovered that all of the birds, no matter how large or whether their posture was crouched or upright, negotiated the obstacle using the same strategy. Daley admits that she was surprised. ‘I thought that we would find that the small animals would crouch and extend the leg to buffer terrain variations and maintain a relatively smooth body motion’, she says, adding that she had expected the larger birds to vault up on to the obstacle and down the other side. Instead, all of the birds appeared to launch themselves up on to the obstacle and crouch slightly on top of it before extending their legs as they descended back down. ‘It's a compromise strategy in a sense’, says Daley.Meanwhile, Daley was also investigating the physical factors – known as task-level priorities – that influence how birds negotiate uneven terrain in collaboration with Jonathan Hurst, Christian Hubicki and Daniel Renjewski from Oregon State University, USA. The engineers built a computer model to simulate the running birds, and Daley says, ‘We used the model to say, here are two alternative “task level priorities”, one of them being to prioritise stability – to try to return to a steady gait as quickly as possible – or alternatively to minimise energy cost’. Simulating heavy birds with long legs and lighter birds with shorter legs, the team found that instead of evolving to prioritise stability when running over an obstacle, the birds' movements were determined by the need to move economically and avoid injury. ‘What you find is that the model does something very similar to birds when you minimise energy cost and control the leg posture at the start of stance to avoid excessive leg loading’, says Daley, who hopes that she and Hurst can now begin to apply the lessons learned from running birds to build stable bipedal robots.

Brachycephalic obstructive airway syndrome: a growing problem

Brachycephalic obstructive airway syndrome: a growing problem

Immersed in ethics

Martin Whiting is a lecturer in veterinary ethics and law at the Royal Veterinary College, and has submitted a PhD on the concept of justice within the profession. He is also interested in the ways in which vets and veterinary nurses behave in practice, including elements of the ethics of evidence‐based veterinary medicine and informed consent

Ten-minute chat

Sara Jones-Richards graduated from the Royal Veterinary College this year. She was recently appointed as an ambassador for the National Sheep Association's (NSA's) Next Generation initiative.

How do Students Approach Lameness? A Case Study

Reasons for performing studyIt is unknown how students develop lameness assessment skills.ObjectivesTo quantify student performance, visual approaches and attitudes to lameness evaluation.Study designComparison of student cohorts.MethodsTwenty 3rd year (inexperienced cohort) and thirteen 4th to 5th year (experienced cohort) students evaluated 30 video clips showing horses on the straight line or circle, followed by a general questionnaire. Eyetracking records (Tobii X102) were collected in parallel. The percentage of correctly evaluated horses was calculated based on verified expert opinion. From the eyetracking records on the straight line, the percentage time spent on different regions on the horse was calculated and compared between cohorts.ResultsFor both cohorts, while the correct detection of lameness per se was high (median ≥92%), detection of the correct limb was lower (median 40–80% depending on quarters and cohort) and detection of sound horses was at chance level (median = 50%). The correct limb was indicated significantly more often by the experienced cohort (P ≤ 0.032) except for forelimb lameness on the circle (P = 0.053). The inexperienced cohort dedicated more time to looking at limb movement, while the experienced cohort focused on head and pelvis movement. Students judged their expected task performance realistically, on average underestimating themselves slightly by around 8%. The task difficulty was rated as a mean (s.d.) of 4.10 (0.48) out of 5 by the inexperienced and 3.35 (0.47) by the experienced cohort.ConclusionsLameness detection skills evolve and improve over the course of the curriculum, with a shift from limb assessment to upper body assessment. Students must learn to reliably determine soundness, and hindlimb lameness proved more difficult than forelimb lameness. Students find lameness detection comparatively difficult, but have a realistic understanding of their skill level, suggesting that they can determine their needs for further practice.Ethical animal research: No animals were used in the study. Video recordings were selected from the archive of R.K. Smith collected during clinical investigations. Explicit owner informed consent for participation in this study was not stated. Sources of funding: S.D. Starke's PhD was funded by the Mellon Trust via the Royal Veterinary College. Competing interests: None.

Fifty Ways to Do Your Lameness: The Relationship Between Various Pelvis‐Based Visual Lameness Pointers During Hindlimb Lameness

Reasons for performing studyThe relationship between pelvic hindlimb lameness pointers remains unclear.ObjectivesTo examine sacrum and tubera coxae (TC) based movement asymmetry across different lameness degrees, patterns and changes in pelvic rotation.Study designParameter regression and rigid body model.MethodsVertical displacement of left and right tubera coxae (LTC, RTC) and sacrum was quantified experimentally in 107 horses with varying lameness degrees using inertial sensors. To investigate the theoretical relationship between pointers, a geometrical model of pelvis movement was created in Matlab. The model predicts TC movement based on experimentally derived pelvic rotation and computer‐generated asymmetrical sacrum movement. Further, the effect of changes in pelvic rotation on TC‐based lameness pointers was quantified. For both, experimental and model data, asymmetry measures corresponding to visual assessment strategies of veterinarians were calculated and contrasted.ResultsExperimental data showed that upward movement amplitudes for sacrum and TC were strongly correlated (r ≥ 0.96). Regression showed that differences were greater between amplitudes of LTC/RTC than sacrum (slope 1.18; r2 = 0.94; P&lt;0.001); however, for ratios the reverse held true (slope 0.86; r2 = 0.92; P&lt;0.001). The model predicted experimentally determined tubera coxae asymmetry well. While the model data matched the experimental scaling relationship between amplitude ratios, it predicted a slightly shallower slope for amplitude differences. Perturbing the model with a different rotational range of movement, an offset in pelvic rotation and asymmetrical pelvic rotation affected observable TC‐based asymmetry depending on the chosen assessment strategy.ConclusionsDetecting lameness based on sacrum or comparative TC movement can give similar results. Using comparative TC movement for lameness detection would be susceptible to changes in pelvic rotation which a lame horse may adopt. Hence, assessment of multiple pelvis‐based lameness pointers can help establishing nonobvious hindlimb lameness.Ethical animal research: The experimental component of this study was approved by the RVC Ethics Committee. Some horses were included with owner informed consent and data from clinical cases were recorded as part of lameness investigations. Sources of funding: S.D. Starke's PhD was funded by the Mellon Trust via the Royal Veterinary College. Competing interests: None.