RVC Repository (Royal Veterinary College)
Not a member yet
10877 research outputs found
Sort by
Emergency management of the polytrauma patient
No full textBackground: Polytrauma is a commonly seen emergency in veterinary practice and is defined as two or more injuries involving multiple body parts or organ systems. One or more of these injuries may be life threatening and patients can rapidly deteriorate. The critical nature of polytrauma cases highlights the need for a coordinated team approach to their care to ensure the best possible outcome for the patient.Aim of the article: This article discusses the pathophysiology of trauma, triage, emergency stabilisation and diagnostics of the trauma patient, highlighting challenges of managing polytrauma patients and the importance of teamwork and a collaborative approach in providing optimal car
Engineered pulmonary artery tissues for measuring contractility, drug testing and disease modelling
No full textBackground and PurposeVasoreactivity of pulmonary arteries regulates blood flow through the lungs. Excessive constriction of these vessels contributes to pulmonary arterial hypertension (PAH), a progressive and incurable condition, resulting in right heart failure. The search for new and improved drug treatments is hampered by laboratory models that do not reproduce the vasoactive behaviour of healthy and diseased human arteries.Experimental ApproachWe have developed an innovative technique for producing miniature, three-dimensional arterial structures that allow proxy evaluation of human pulmonary artery contractility. These "engineered pulmonary artery tissues" or "EPATs" are fabricated by suspending human pulmonary artery vascular smooth muscle cells (VSMCs) in fibrin hydrogels between pairs of silicone posts, located on custom-made racks, in 24-well culture plates.Key ResultsEPATs exhibit rapid, robust and reproducible contraction responses to vasoconstrictors (KCl, ET-1, U46619) as well as relaxation responses to clinically approved PAH vasodilatory drugs that target several signalling pathways, such as bosentan, epoprostenol, selexipag and imatinib. EPATs composed of pulmonary artery VSMCs from PAH patients exhibit enhanced contraction to vasoconstrictors and relaxation in response to vasodilators. We also demonstrate the incorporation of endothelial cells into EPATs for the measurement of endothelium-dependent dilatory responses.Conclusion and ImplicationsWe demonstrate the capacity and suitability of EPATs for studying the contractile behaviour of human arterial cells and preclinical drug testing. This novel biomimetic platform has the potential to dramatically improve our understanding and treatment of cardiovascular disease
Transmission dynamics of highly pathogenic avian influenza among multiple waterfowl species and backyard poultry: the impact of the stopover period
No full textSpillover of Highly Pathogenic Avian Influenza (HPAI) to backyard poultry via migratory birds threatens the poultry industry and public health. To improve the understanding of spillover events, we developed a stochastic compartmental mathematical model of HPAI transmission dynamics at the waterfowl-backyard poultry interface in a high-risk area for HPAI introduction into poultry. The model described the infection spread among resident and migratory waterfowl and backyard poultry farms and was validated with historical outbreak data in backyard poultry farms and swan mortalities. We used the model to assess the impact of the timing and duration of migratory birds' stopover period on the probability of HPAI infection in backyard poultry farms. Additionally, we predicted mortality in a sentinel bird species and assessed the impact of HPAI virulence and immunity in a resident reservoir species on the HPAI transmission dynamics. The stopover duration of the reservoir species predicts the HPAI infection probability in backyard poultry farms from waterfowl communities, but the stopover timing has no effect. HPAI virus virulence and immunity against the virus impact the transmission risk to backyard poultry. Understanding factors influencing reservoir species' migration stopover duration in a location will aid HPAI outbreak forecasting and control in backyard poultry farms
Epidemiology of haemangiosarcoma diagnosed in dogs under primary veterinary care in the United Kingdom: Frequency and risk factors
No full textBackground This study aimed to estimate the frequency and risk factors for haemangiosarcoma diagnosis in dogs.Methods Cases diagnosed in UK primary care practices in 2019 were identified from VetCompass records, andpotential risk factors were manually extracted. Two nested case-control studies were conducted: one including alldiagnosed haemangiosarcoma with or without histopathological confirmation (clinical diagnosis), and anotherlimited to histopathologically confirmed haemangiosarcoma. Logistic regression modelling was used to identify riskfactors among dogs aged five years or older.Results Of 2,250,741 dogs of all ages, 801 were diagnosed with haemangiosarcoma in 2019, giving an annualincidence risk of 0.036% (95% confidence interval [CI] 0.033–0.038%). Of the 1,066,381 dogs aged at least five years,there were 790 incident cases (0.074%, 95% CI 0.069–0.079%). After excluding dogs that belonged to a small practicegroup, risk factor analysis compared 788 clinically diagnosed cases with 1,064,187 controls. Ten breeds had increasedodds of clinical haemangiosarcoma diagnosis compared to crossbreed dogs. Breeds with the highest odds wereDogue de Bordeaux (OR 9.56, 95% CI 4.17–21.91), Flat Coated Retriever (OR 8.33, 95% CI 4.03–17.20) and GermanShepherd Dog (OR 6.35, 95% CI 4.86–8.29). In the histopathological subset, the Flat Coated Retriever showed highestodds (OR 17.5, 95% CI 7.88–38.67). Compared to dogs aged 7 < 9 years old, older age was a significant risk factor inboth clinical (11 < 13 years, OR 2.83, 95% CI 2.31–3.48) and histopathological diagnoses (9 < 11 years, OR 1.90, 95%CI 1.40–2.58). In the broader clinically diagnosed analysis, increased odds were also associated with neutered males(OR 1.49, 95% CI 1.17–1.90) and clinics in the least deprived areas (OR 1.66, 95% CI 1.18–2.34). Dogs attending clinicsin mixed urban-rural areas had decreased odds of clinical haemangiosarcoma diagnosis compared to those in urbanareas (OR 0.71, 95% CI 0.57–0.89).Conclusions Several strong breed associations for diagnosis of haemangiosarcoma were identified which cansupport earlier clinical suspicion and targeted diagnostics, especially where early signs are non-specific. Breedrelatedassociations with haemangiosarcoma diagnosis may suggest a genetic predisposition which may be targetedthrough changes in breeding practices and promotion of outcrossing in high-risk breeds
Yorkshire Terriers under primary veterinary care in the UK – demography and disorders
No full textBackgroundThe Yorkshire Terrier is a long-established and commonly owned dog breed. This study aimed to explore anonymised primary-care veterinary clinical data from the VetCompass Programme to characterise the demography, common disorders and longevity of the general population of Yorkshire Terriers in the UK in 2016.ResultsYorkshire Terriers composed 28,032 (3.10%) of the study population of 905,542 dogs under veterinary care in 2016. Annual proportional birth rates decreased in popularity between 2005 and 2016, from 3.54% of all dogs born in 2005 to 2.15% in 2016. The median adult bodyweight was 5.06 kg (IQR 3.81–6.49, range 1.01-15.00). Clinical records from a random sample of 3,308/28,032 (11.80%) Yorkshire Terriers were manually reviewed to extract information on all disorders diagnosed during 2016. The most commonly diagnosed disorders were periodontal disease (21.10%, 95% CI: 19.71–22.49), overgrown nail(s) (6.47%, 95% CI: 5.63–7.31), anal sac impaction (3.99%, 95% CI: 3.32–4.66), overweight/obesity (3.72%, 95% CI: 3.07–4.36) and persistent deciduous teeth (3.57%, 95% CI: 2.94–4.20). Among the 464/3,308 (14.03%) Yorkshire Terriers that died during the study period, the median age at death was 13.56 years (IQR 11.30–15.15, range 0.06–19.08). The most common disorder groups causing death were brain disorders (9.79%, 95% CI: 6.79–12.78) and kidney disorders (8.73%, 95% CI: 5.88–11.58).ConclusionsThe current study identifies a reducing ownership trend for Yorkshire Terriers in the UK. Disorders that are common and appear predisposed in Yorkshire Terriers include periodontal disease, persistent deciduous teeth and patellar luxation. Overall, the Yorkshire Terrier has high longevity, which is suggestive of robust overall health
Recurrent cerebral ischaemic stroke in a Persian cat
No full textA 4-year-old, 4.8 kg, male, neutered Persian cat was presented 12 hours following the acute onset of initially progressive, then subsequently improving, left-sided weakness. Neurological examination revealed non-ambulatory left-sided hemiparesis. Postural reactions were absent in the left thoracic and pelvic limbs, and menace response was absent in the left eye. Neuroanatomical localisation was to the right forebrain, with multifocal involvement not excluded. Brain magnetic resonance imaging revealed a discrete T2 hyperintense intra-axial lesion with restricted diffusion affecting the grey matter of the right frontal, temporal and piriform lobes. The most likely diagnosis was an ischaemic infarct of the parenchyma supplied by the right middle cerebral artery. The cat improved over 2 weeks, but 4 months later, experienced several transient abnormal episodes. Repeat imaging revealed a new lacunar ischaemic infarct within the territory of the left striate artery. Probable internal vertebral venous plexus and basilar sinus thromboses were also identified, suggestive of an underlying hypercoagulable state
Acute Respiratory Distress Syndrome in Veterinary Medicine-The ARDSVet Definitions
No full textObjective To use a systematic, evidence-based consensus process to develop updated definitions for acute respiratory distress syndrome (ARDS) in veterinary medicine to facilitate its recognition and diagnosis.Design International consensus conference series involving 12 multidisciplinary international content experts from three countries, using consensus conference methodology and implementation science. A systematic review of the literature was carried out for ARDS and acute lung injury in veterinary medicine. Updated definitions of ARDS were generated based on synthesis of human and veterinary literature. Consensus on the definitions was achieved through Delphi-style surveys involving the above subject matter experts. Draft recommendations were made available through industry specialty listservs for feedback, which was incorporated in the final definitions.Results Updated definitions were developed for Veterinary Acute Respiratory Distress Syndrome (ARDSVet) in small animals (dogs and cats) and large animals (equids). For small animals, 690 publications were identified for dogs and 99 were identified for cats in the initial literature search. Seventeen cats and 103 dogs with ARDS were represented across these publications. For the initial literature search in large animals, there were 83 equid, five camelid, 158 pig, 714 sheep and goat, and 270 cattle publications identified. Additionally, 1084 publications were found across all large animals that addressed interstitial lung disease. Five adult equids and 136 foals with ARDS were represented across these publications. The updated ARDSVet definitions incorporate criteria for risk factors, origin and timing of pulmonary edema, and impaired oxygenation, with severity stratified by oxygenation and definitions for both intubated and nonintubated animals.Conclusions The evidence review and consensus process resulted in updated definitions that can be used to improve the recognition of veterinary ARDS as well as facilitate and standardize future research, including the development of an ARDS registry and eventual treatment recommendations
Spatiotemporal analysis of dystrophin expression during muscle repair
No full textBackgroundDystrophin mRNA is produced from a very large genetic locus and transcription of a single mRNA requires approximately 16 h. This prolonged interval between initiation and completion results in unusual transcriptional behaviour: in skeletal muscle, myonuclei express dystrophin continuously and robustly, yet degrade mature transcripts shortly after completion. Consequently, most dystrophin mRNA is nascent, not mature. This implies expression is principally controlled post-transcriptionally, a mechanism that circumvents transcriptional delay, allowing rapid responses to change in demand. Dystrophin protein is however highly stable, with slow turnover: in healthy muscle, despite constant production of dystrophin mRNA, demand is low and the need for responsive expression is minimal. We reasoned this system instead exists to control dystrophin expression during rare periods of elevated but changing demand, such as during muscle development or repair, when newly formed fibres must establish sarcolemmal dystrophin rapidly.MethodsWe assessed dystrophin mRNA (both nascent and mature) and dystrophin protein in regenerating skeletal muscle following injury, using a combination of qPCR, immunofluorescence and in-situ hybridisation to determine timing and location of expression during the repair process.ResultsWe reveal a complex program that suggests control at multiple levels: nascent transcription is detectable even prior to overt myoblast fusion, suggesting cells 'pay in advance' to minimise subsequent delay. During myotube differentiation and maturation, when sarcolemmal demands are high, initiation increases only modestly while mature transcript stability increases markedly to generate high numbers of mature dystrophin transcripts, a state that persists until repair is complete, when oversupply and degradation resumes.ConclusionOur data demonstrate that dystrophin mRNA is indeed chiefly controlled by turnover, not initiation: degradation consequently represents a potential therapeutic target for maximising efficacy of even modest dystrophin restoration