Untangling the stranglehold through mathematical modelling of Streptococcus equi subspecies equi transmission

Strangles, a disease caused by infection with Streptococccus equi subspecies equi (S. equi), is endemic worldwide and one of the most frequently diagnosed infectious diseases of horses. Recent work has improved our knowledge of key parameters of transmission dynamics, but important knowledge gaps remain. Our aim was to apply mathematical modelling of S. equi transmission dynamics to prioritise future research areas, and add precision to estimates of transmission parameters thereby improving understanding of S. equi epidemiology and quantifying the control effort required. A compartmental deterministic model was constructed. Parameter values were estimated from current literature wherever possible. We assessed the sensitivity of estimates for the basic reproduction number on the population scale to varying assumptions for the unknown or uncertain parameters of: (mean) duration of carriership (1∕γC), relative infectiousness of carriers (f), proportion of infections that result in carriership (p), and (mean) duration of immunity after natural infection (1∕γR). Available incidence and (sero-)prevalence data were compared to model outputs to improve point estimates and ranges for these currently unknown or uncertain transmission-related parameters. The required vaccination coverage of an ideal vaccine to prevent major outbreaks under a range of control scenarios was estimated, and compared available data on existing vaccines. The relative infectiousness of carriers (as compared to acutely ill horses) and the duration of carriership were identified as key knowledge gaps. Deterministic compartmental simulations, combined with seroprevalence data, suggest that 0.05 Collapse

Key Words

• Epidemiology
• Infectious disease modelling
• Streptococcus equi

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Stakeholder opinion-led study to identify canine priority diseases for surveillance and control in the UK

BACKGROUND

Many pathogens cause disease in dogs; however, meaningful surveillance in small companion animals is often only possible for the most impactful diseases. We describe the first stakeholder opinion-led approach to identify which canine infectious diseases should be prioritised for inclusion in surveillance and control strategies in the UK.

METHODS

Participants were identified through a stakeholder analysis. A multicriteria decision analysis was undertaken to establish and weight epidemiological criteria for evaluating diseases, and a Delphi technique was employed to achieve a consensus among participants on the top-priority canine diseases.

RESULTS

Nineteen stakeholders from multiple backgrounds participated in this study. Leptospirosis and parvovirus were identified as the top two endemic diseases of concern, while leishmaniosis and babesiosis were the top two exotic diseases. Respiratory and gastrointestinal diseases were identified as the top two syndromes of concern.

LIMITATIONS

Due to the COVID-19 pandemic, the number of participants was reduced. Despite this, a representative multidisciplinary sample of relevant stakeholders contributed to the present study.

CONCLUSIONS

Findings from this study are being used to inform the development of a future UK-wide epidemic response strategy. This methodology could provide a blueprint for other countries.

Effect of speed and water depth on limb and back kinematics in Thoroughbred horses walking on a water treadmill

Water treadmill (WT) exercise may induce limb and back kinematics that meet specific training and rehabilitation goals. The study aimed to investigate the effects of walk speed, at different water depths (WDs), on limb and back kinematics of six Thoroughbreds exercising on a WT. Horses walked at 2.8/4.3/5.5/6.0 km/h (i.e. 0.8/1.2/1.5/1.7 m/s) at dry, metacarpophalangeal and carpal WD. Videography captured limb movement in the sagittal plane. Motion-capture measured thoracolumbosacral flexion-extension (FE), and lateral bend (LB) ranges of movement (ROM) using skin surface markers on the sixth, tenth, thirteenth, eighteenth thoracic, third and fifth lumbar, and third sacral spinous processes. Inertial-motion-sensors measured poll, withers and pelvic displacements. Following preliminary univariable analyses, multivariable mixed-effects linear-regression analyses were used to examine the relationship between speed, WD and each outcome variable (P < 0.05). Peak metacarpophalangeal, carpal and tarsal joint flexion increased with speed (P ≤ 0.002) and depth combined (P 0.001) while peak metatarsophalangeal flexion increased with WD only (P 0.001). Thoracolumbar FE-ROM between T10 and L3 and hindlimb retraction was increased by speed and WD combined (P 0.001). Hindlimb protraction was increased by speed (P 0.001) while hindlimb retraction was increased by speed and WD combined (P 0.001). Dorsoventral poll displacement was increased by speed (P 0.001) and carpal WD (P = 0.013), craniocaudal poll displacement was increased by speed and WD combined (P 0.001). Pelvic (tubera coxae and sacrum) dorsoventral displacements increased with speed and WD combined (P 0.001). Understanding the effects of speed and WD on limb, back and pelvic kinematics will improve decision making relating to dry and WT exercise within training.

Over a decade of an eating disorders treatment program: Where to from here?

OBJECTIVE

Currently available treatments for eating disorders lack efficacy resulting in poor outcomes for patients. In this paper, we describe a number of issues that we have identified in our clinical service, which are not unique to our treatment program.

CONCLUSIONS

The issues described are common among eating disorder services worldwide and need to be addressed in order to move the field forward. We provide a number of solutions and research areas that need greater focus so that we are able to improve the efficacy of eating disorder treatment services.

A Review on Equine Influenza from a Human Influenza Perspective

Influenza A viruses (IAVs) have a main natural reservoir in wild birds. IAVs are highly contagious, continually evolve, and have a wide host range that includes various mammalian species including horses, pigs, and humans. Furthering our understanding of host-pathogen interactions and cross-species transmissions is therefore essential. This review focuses on what is known regarding equine influenza virus (EIV) virology, pathogenesis, immune responses, clinical aspects, epidemiology (including factors contributing to local, national, and international transmission), surveillance, and preventive measures such as vaccines. We compare EIV and human influenza viruses and discuss parallels that can be drawn between them. We highlight differences in evolutionary rates between EIV and human IAVs, their impact on antigenic drift, and vaccine strain updates. We also describe the approaches used for the control of equine influenza (EI), which originated from those used in the human field, including surveillance networks and virological analysis methods. Finally, as vaccination in both species remains the cornerstone of disease mitigation, vaccine technologies and vaccination strategies against influenza in horses and humans are compared and discussed.

Evaluation of a Housing First programme for people from the public mental health sector with severe and persistent mental illnesses and precarious housing: Housing, health and service use outcomes

AIMS AND CONTEXT

This paper reports the evaluation of the Doorway program (2015-18) in Melbourne, Australia. Doorway extends the original Housing First (HF) model in providing housing support to people with precarious housing at-risk of homelessness with Serious and Persistent Mental Illnesses (SPMIs) receiving care within Victoria's public mental health system. Doorway participants source and choose properties through the open rental market, and receive rental subsidies, assistance, advocacy and brokerage support through their Housing and Recovery Worker (HRW). The aim of this study is to estimate Doorway's impact on participants' housing, quality of life and mental health service use.

METHODOLOGY

The study employed a a quasi-experimental study design with a comparison group, adjusted for ten potential confounders. The primary outcome measure was days of secure housing per participant. Secure housing status, health service usage and quality of life (HoNOS) data were extracted from participants' electronic hospital and Doorway records in deidentified, non-reidentifiable form. Analysis for continuous outcome variables was based on multivariate GLM modelling.

RESULTS

Doorway housed 89 (57%) of 157 accepted participants. The 157 Doorway participants overall were also housed for significantly more days (119.4 extra days per participant) than control participants, albeit after some delay in locating and moving into housing (mean 14 weeks). There was a significant, positive Doorway effect on health outcomes (all and one dimension of the HoNOS). Doorway participants had significantly reduced length of stay during acute and community hospital admissions (7.4 fewer days per participant) compared with the control group.

CONCLUSION

The Doorway model represents a new and substantial opportunity to house, enhance health outcomes and reduce mental health service use for people with SPMIs from the public mental health sector and at-risk of homelessness.

Globetrotting strangles: the unbridled national and international transmission of Streptococcus equi between horses

The equine disease strangles, which is characterized by the formation of abscesses in the lymph nodes of the head and neck, is one of the most frequently diagnosed infectious diseases of horses around the world. The causal agent, Streptococcus equi subspecies equi, establishes a persistent infection in approximately 10 % of animals that recover from the acute disease. Such 'carrier' animals appear healthy and are rarely identified during routine veterinary examinations pre-purchase or transit, but can transmit S. equi to naïve animals initiating new episodes of disease. Here, we report the analysis and visualization of phylogenomic and epidemiological data for 670 isolates of S. equi recovered from 19 different countries using a new core-genome multilocus sequence typing (cgMLST) web bioresource. Genetic relationships among all 670 S. equi isolates were determined at high resolution, revealing national and international transmission events that drive this endemic disease in horse populations throughout the world. Our data argue for the recognition of the international importance of strangles by the Office International des Épizooties to highlight the health, welfare and economic cost of this disease. The Pathogenwatch cgMLST web bioresource described herein is available for tailored genomic analysis of populations of S. equi and its close relative S. equi subspecies zooepidemicus that are recovered from horses and other animals, including humans, throughout the world. This article contains data hosted by Microreact.

Similarities and differences in people accessing prevention and recovery care services and inpatient units in Victoria, Australia

Background

There is an emerging international literature demonstrating clinical and cost-effectiveness of sub-acute residential mental health services. To date, however, there is limited information on the profile of consumers accessing these models of care. This study aimed to understand the profile of the population served by adult sub-acute residential mental health services in Victoria, Australia (known as Prevention and Recovery Care; PARC) and to compare PARC service consumers with consumers admitted to psychiatric inpatient units within public hospitals.

Method

Using 5 years (2012–2016) of a state-wide database of routinely collected individual level mental health service data, we describe the socio-demographic and clinical profile of PARC service consumers compared to consumers of psychiatric inpatient units including for primary diagnosis and illness severity. Using admissions as the unit of analysis, we identify the characteristics that distinguish PARC service admissions from psychiatric inpatient admissions. We also examine and compare length of stay for the different admission types.

Results

We analysed 78,264 admissions representing 34,906 individuals. The profile of PARC service consumers differed from those admitted to inpatient units including for sex, age, diagnosis and illness severity. The odds of an admission being to a PARC service was associated with several socio-demographic and clinical characteristics. Being male or in the youngest age grouping (< 20 years) significantly reduced the odds of admission to PARC services. The presence of primary diagnoses of schizophrenia and related disorders, mood, anxiety or personality disorders, all significantly increased the odds of admission to PARC services. Predictors of length of stay were consistent across PARC and inpatient admission types.

Conclusions

Our findings suggest PARC services may serve an overlapping but distinguishably different consumer group than inpatient psychiatric units. Future research on sub-acute mental health services should be cognizant of these consumer differences, particularly when assessing the long-term effectiveness of this service option.

The efficacy, safety and acceptability of emergency embedded Psychiatry Assessment and Planning Units: An evaluation of Psychiatry Assessment and Planning Units in close proximity to their associated emergency departments

OBJECTIVE

To determine the efficacy, safety and acceptability as well as the patient demographics of three newly developed emergency department-embedded Psychiatric Assessment and Planning Units located in Metropolitan Melbourne at Austin, Peninsula and Eastern Health Services.

METHODS

The evaluation reviewed a 12-month period of service activity from 1 September 2017 to 31 August 2018, when all three Psychiatric Assessment and Planning Units services were operational. A 12-month period from 1 September 2014 to 31 August 2015 was compared as the pre-Psychiatric Assessment and Planning Units period. Mixed qualitative and quantitative methods were used. This included semi-structured interviews of 30 Psychiatric Assessment and Planning Units patients and 30 emergency department staff (10 of each for all 3 sites), patient survey, statistical analysis of Client Management Interface data for the emergency department and related Psychiatric Assessment and Planning Units as well as audit of RISKMAN registers.

RESULTS

There were 365 Austin, 567 Eastern and 791 Peninsula Psychiatric Assessment and Planning Units admissions. Psychiatric Assessment and Planning Units were generally well accepted by patients and emergency department staff, relatively safe, operating within the Key Performance Indicators with mixed effect on emergency department flow. Austin emergency department processing times improved post-Psychiatric Assessment and Planning Units (4 hours 57 minutes to 4 hours 19 minutes; p < 0.001) while deteriorating at Eastern and Peninsula. Adjustment Disorder and Depression and Borderline Personality Disorder were the most common admission diagnoses. While the Psychiatric Assessment and Planning Units had mixed utility on emergency department processing times, they appear to serve a demographic not previously accommodated in traditional emergency department psychiatry models.

CONCLUSION

The emergency department-embedded Psychiatric Assessment and Planning Unit model of care appears effective on some measures, safe and acceptable to patients and staff. The Psychiatric Assessment and Planning Units seem to service a group not previously accommodated in traditional emergency psychiatry models.

Borderline personality disorder and eating disorders: a trans-diagnostic approach to unravelling diagnostic complexity

OBJECTIVES

This opinion paper considers co-morbid borderline personality disorder (BPD) and eating disorders and proposes that a trans-diagnostic approach looking at presenting problems and treatment approaches may be of value.

CONCLUSIONS

Trans-diagnostic elements can be identified across the two syndromes. Trans-diagnostic elements appear to include some shared aetiological factors as well as some shared syndromal components. The shared syndromal components include problems with affect, interpersonal problems, problems with self-concept and impulsivity. The pathoplastic effects of culture, attitudes to fatness and the neurobiology of starvation and/or restriction of intake are crucial to integrate into the understanding of co-morbidity of these two disorders. Trans-diagnostic approaches to treatment lead to trans-diagnostic improvements across the two disorders.

Key features of an innovative sub-acute residential service for young people experiencing mental ill health

BACKGROUND

Numerous studies across international settings have highlighted a need to improve the appropriateness and continuity of services for young people experiencing mental ill health. This paper examines key features of a sub-acute youth mental health residential service model, Youth Prevention and Recovery Care (Y-PARC) service. Y-PARC provides up to 4 weeks care to 16 to 25 year-olds at risk of hospitalisation and to those transitioning out of hospital inpatient units. The research was conducted at one of three Y-PARCs located in Victoria, Australia.

METHODS

This paper presents findings from analysis of two data sources collected during evaluation of a Y-PARC service in 2015-17. Routinely collected administrative data of Y-PARC residents (n = 288) were analysed and semi-structured interviews were conducted with 38 participants: a) former residents (n = 14); b) family members of group a) (n = 5); key stakeholders (n = 9); and, Y-PARC staff (n = 10 respondents in 3 group interviews). Analysis of the qualitative data was thematic and structured by the interview guide, which covered the key service aims.

RESULTS

Consistent with the aims of the service, respondents described practice at Y-PARC that aligns with recovery-oriented care. Key features emphasised were: a safe and welcoming environment for residents and families; provision of person-centred care; promotion of autonomy and self-help; informal interactions with staff allowing for formation of naturalistic relationships; time spent with other young people with similar experiences; and, assurance upon exit that the 'door is always open.' High levels of satisfaction were reported. Outcomes described included: improved resilience; better understanding of mental health; the importance of seeking help; and, stronger connections to therapeutic services. Longer and multiple stays were associated with progressive and sustained change. Family members and stakeholders widely reported that the service fills a gap between community services and acute inpatient mental health hospital wards. Some challenging areas of practice identified included: integration of evidence-based psychosocial interventions; provision of care within a model that blends clinical and psychosocial support services; and, negotiation of family-inclusive practice.

CONCLUSIONS

The Y-PARC service model shows promise with young people experiencing mental ill health, particularly in improving the range and availability of options across a spectrum of need.

Identification of modifiable factors associated with owner-reported equine laminitis in Britain using a web-based cohort study approach

Background

Equine laminitis is a complex disease that manifests as pain and lameness in the feet, often with debilitating consequences. There is a paucity of data that accounts for the multifactorial nature of laminitis and considers time-varying covariates that may be associated with disease development; particularly those that are modifiable and present potential interventions. A previous case-control study identified a number of novel, modifiable factors associated with laminitis which warranted further investigation and corroboration. The aim of this study was to identify factors associated with equine laminitis in horses/ponies in Great Britain (GB) using a prospective, web-based cohort study design, with particular interest in evaluating modifiable factors previously identified in the case-control study.

Results

Self-selected horse/pony owners in GB submitted initial baseline and follow-up health and management questionnaires for 1070 horses/ponies between August 2014 and December 2016. The enrolled horses/ponies contributed 1068 horse-years at risk with a median of 38 days between questionnaire submissions. Owners reported 123 owner-recognised and/or veterinary-diagnosed episodes of active laminitis using a previously-validated laminitis reporting form. Multivariable Cox regression modelling identified 16 risk/protective factors associated with laminitis development. In keeping with the previous case-control study, a prior history of laminitis (particularly non-veterinary-diagnosed episodes), soreness after shoeing/trimming and weight gain were associated with higher rates of laminitis. There is now strong evidence that these risk factors should be used to guide future recommendations in disease prevention. Factors with some prior evidence of association included breed, steroidal anti-inflammatory administration, transport and worming. The modifiable factors amongst these should be the focus of future laminitis studies. The remainder of the identified factors relating to health, turnout and grazing management and feeding are novel, and require further investigation to explore their relationship with laminitis and their applicability as potential interventions.

Conclusions

This study has demonstrated a temporal relationship between a number of horse- and management-level factors and laminitis, identifying potential interventions and important risk groups for which these interventions would be of particular importance. These results serve as a sound evidence-base towards the development of strategic recommendations for the horse/pony-owning population to reduce the rate of laminitis in GB.

Electronic supplementary material

The online version of this article (10.1186/s12917-019-1798-8) contains supplementary material, which is available to authorized users.

Incidence and clinical signs of owner-reported equine laminitis in a cohort of horses and ponies in Great Britain

BACKGROUND

Previous robust epidemiological studies of equine laminitis have utilised only veterinary-diagnosed episodes of disease, potentially underestimating true disease frequency.

OBJECTIVES

To estimate the incidence of, and describe clinical signs associated with, owner-reported active laminitis in horses/ponies, using both veterinary-diagnosed and nonveterinary-diagnosed episodes.

STUDY DESIGN

Prospective cohort.

METHODS

Data were collected from horse/pony owners in Great Britain between August 2014 and December 2016 using a web-based application. The incidence of owner-reported laminitis was estimated using both first incident and repeat episodes reported during the study period via a previously validated laminitis reporting form. Owner-reported clinical signs present in these episodes were recorded.

RESULTS

A total of 1070 horses/ponies contributed 1068 horse-years at risk (HYAR) and 123 active laminitis episodes were reported in 97 animals. Sixty-two of these episodes (50.4%, 95% confidence interval [CI] 41.6, 59.2%) were veterinary-diagnosed and 75.3% (CI 66.7, 83.8%; n = 73) of horses/ponies reported to have laminitis during the study had a previous laminitis history. Overall owner-reported first episode incidence was 9.6 episodes (CI 7.8, 11.7)/100 HYAR, whereas incidence including repeat episodes was 11.5 episodes (CI 9.7, 13.7)/100 HYAR. Laminitis occurred throughout the year with no significant differences between seasonal incidence estimates. Incidence was highest in Connemara and New Forest and lowest in Draught and Cob breed categories. The most prevalent owner-reported clinical signs (≥70%) were difficulty turning and a short/stilted or lame walk. Laminitis was reported in all limbs, however; both forelimbs were most commonly affected (62.9%, CI 54.1, 71.7%; n = 73/116).

MAIN LIMITATIONS

Self-selection enrolment of participants may limit generalisability of the findings.

CONCLUSIONS

Laminitis remains a considerable year-round welfare issue of horses and ponies, with frequency estimates utilising owner-reported data more representative of the true impact of the disease. The clinical signs reported by horse/pony owners were reflective of those previously described by veterinary surgeons.

Peer mentoring for eating disorders: evaluation of a pilot program

Background

Eating disorders are serious psychiatric illnesses that are often associated with poor quality of life and low long-term recovery rates. Peer mentor programs have been found to improve psychiatric symptoms and quality of life in other mental illnesses, and a small number of studies have suggested that eating disorder patients may benefit from such programs. The aim of this study is to assess the efficacy of a peer mentor program for individuals with eating disorders in terms of improving symptomatology and quality of life.

Methods

Up to 30 individuals with a past history of an eating disorder will be recruited to mentor 30 individuals with a current eating disorder. Mentoring will involve 13 sessions (held approximately every 2 weeks), of up to 3 h each, over 6 months.

Discussion

This pilot proof-of-concept feasibility study will inform the efficacy of a peer mentoring program on improving eating disorder symptomatology and quality of life, and will inform future randomised controlled trials.

Trial registration

Australian and New Zealand Clinical Trials Registration Number: ACTRN12617001412325. The date of registration (retrospective): 05/10/2017.

Electronic supplementary material

The online version of this article (10.1186/s40814-018-0268-6) contains supplementary material, which is available to authorized users.

Streptococcus equi Infections in Horses: Guidelines for Treatment, Control, and Prevention of Strangles-Revised Consensus Statement

This consensus statement update reflects our current published knowledge and opinion about clinical signs, pathogenesis, epidemiology, treatment, complications, and control of strangles. This updated statement emphasizes varying presentations in the context of existing underlying immunity and carrier states of strangles in the transmission of disease. The statement redefines the “gold standard” for detection of possible infection and reviews the new technologies available in polymerase chain reaction diagnosis and serology and their use in outbreak control and prevention. We reiterate the importance of judicious use of antibiotics in horses with strangles. This updated consensus statement reviews current vaccine technology and the importance of linking vaccination with currently advocated disease control and prevention programs to facilitate the eradication of endemic infections while safely maintaining herd immunity. Differentiation between immune responses to primary and repeated exposure of subclinically infected animals and responses induced by vaccination is also addressed.

Short-Term and Long-Term Physical Effects of Exposure to CS Spray

CS gas (2-chlorobenzylidene malonitrile) is widely used in an incapacitant spray that causes intense lacrimation, blepharospasm and burning sensations in the throat and nose. Questions have been raised about its safety. We obtained information on short-term and long-term symptoms, and performed ear, nose and throat examinations and respirometry at 8–10 months, in 34 young adults who had been exposed to CS spray in a confined space during a confrontation with police. The group was subdivided into those who had been sprayed directly on the face ( n=10) and those exposed indirectly.

At one hour, all but 2 individuals still had symptoms; respiratory and oral symptoms were significantly more prevalent in the directly exposed group. At one month, only oral symptoms were significantly more prevalent. At 8–10 months, symptoms were still reported but there were no differences between the groups and clinical examinations revealed no specific abnormalities.

There was no convincing evidence of long-term physical sequelae from exposure to CS spray.

Equine atypical myopathy in the UK: Epidemiological characteristics of cases reported from 2011 to 2015 and factors associated with survival

BACKGROUND

Equine atypical myopathy (AM) is a toxic rhabdomyolysis associated with ingestion of hypoglycin A, derived typically in Europe, from Acer pseudoplatanus tree. Despite the wide distribution of this tree species in the UK, the number of cases reported annually varies, and there has been an apparent increase in prevalence in recent years. Although AM was first recognised in the UK, epidemiological studies have never been conducted focused solely on this country.

OBJECTIVES

To describe the spatiotemporal distribution, presentation, treatment and outcome of AM cases reported in the UK.

STUDY DESIGN

Retrospective case series.

METHODS

British AM cases reported to the atypical myopathy alert website, between 2011 and 2015 were included (n = 224). Data were obtained via standardised epidemiological questionnaires from owners and veterinarians. Factors associated with survival were assessed using logistic regression.

RESULTS

Most cases reported were from England (87.9%). Survival was 38.6% (n = 73/189). Clinical factors associated with reduced odds of survival included, hypothermia (odds ratio [OR] 0.18; 95% confidence interval [CI] 0.06-0.57; P = 0.01), bladder distension (OR 0.11; CI 0.02-0.59; P = 0.01), tachycardia (OR 0.97; CI 0.94-0.99; P = 0.04) and serum creatine kinase activity >100,000 IU/L (OR 0.17; CI 0.04-0.68; P = 0.01) in the univariable analysis as well as recumbency. The latter was the only sign retained in multivariable analysis (OR = 0.19; CI 0.06-0.62; P = 0.006). Administration of vitamins during the disease was associated with survival (OR 3.75; CI 1.21-11.57; P = 0.02).

MAIN LIMITATIONS

Reporting cases to the Atypical Myopathy Alert Group is voluntary; therefore, under-reporting will result in underestimation of AM cases; furthermore, direct owner-reporting could have introduced misdiagnosis bias.

CONCLUSION

Some areas of the UK reported AM cases more commonly. Clinical signs such as recumbency, rectal temperature, distended bladder and serum creatine kinase activity might be useful prognostic indicators though should be considered in the context of the clinical picture. Treatment with vitamins increases odds of survival.

Deafness in a Young Musician: A Case of Missed Diagnosis

Hearing loss in a young adult can be devastating and prompt diagnosis and treatment of the cause are vital. This case report is of a young musician presenting to the ENT surgeons with deafness and a lower motor neurone facial nerve palsy which was given a presumptive diagnosis of infective pathology but subsequent investigations indicated this was an uncommon presentation of Wegener's Granulomatosis. Treatment involved systemic Cyclophosphamide followed by steroids and Azathioprine. Two years after commencing therapy the disease remains under control but the patient is left with bilateral hearing aids and a grade 3 facial nerve palsy. Diagnosis and treatment of this multi-system disease are discussed.

Designing a field trial of an equine grass sickness vaccine: A questionnaire-based feasibility study

Without an experimental model of equine grass sickness (EGS), a randomised controlled field trial (RCT) represents the only method of evaluating the efficacy of Clostridium botulinum type C vaccination in preventing naturally occurring disease. Clinical trial feasibility is an important aspect of preliminary work undertaken prior to initiating RCTs, estimating parameters that are important for study design. This cross-sectional study aimed to assess the feasibility of conducting a nationwide RCT of a candidate vaccine for EGS based on responses from a sample of British equine veterinary practices (n = 119/284). Seventy-three percent of practices had attended ≥1 EGS case within the preceding 2 years (median four cases), and 51.3% regularly attended recurrently affected premises. Veterinary surgeons had greater confidence diagnosing acute/subacute EGS based solely on history and clinical signs compared to chronic EGS. Ninety-one percent of respondents (n = 103/113) considered the proposed RCT to be important/very important to equine veterinary research. Ninety-one percent of respondents (n = 102/112) indicated preparedness to assist in owner recruitment and 92.9% (n = 104/112) indicated willingness to participate in a RCT. The most frequent reasons for practices declining to participate were low incidence of EGS (n = 4), did not believe clients would wish to participate (n = 3) and amount of paperwork/data collection involved (n = 2). There was considerable support amongst participating veterinary practices for a RCT evaluating the efficacy of Clostridium botulinum vaccination for the prevention of EGS in Britain. Substantial proportions of participating practices would be prepared to participate in the RCT and regularly attended EGS-affected premises that would meet trial inclusion criteria.

Polarisation of equine pregnancy outcome associated with a maternal MHC class I allele: Preliminary evidence

Identification of risk factors which are associated with severe clinical signs can assist in the management of disease outbreaks and indicate future research areas. Pregnancy loss during late gestation in the mare compromises welfare, reduces fecundity and has financial implications for horse owners. This retrospective study focussed on the identification of risk factors associated with pregnancy loss among 46 Thoroughbred mares on a single British stud farm, with some but not all losses involving equid herpesvirus-1 (EHV-1) infection. In a sub-group of 30 mares, association between pregnancy loss and the presence of five common Thoroughbred horse haplotypes of the equine Major Histocompatibility Complex (MHC) was assessed. This involved development of sequence specific, reverse transcriptase polymerase chain reactions and in several mares, measurement of cytotoxic T lymphocyte activity. Of the 46 mares, 10 suffered late gestation pregnancy loss or neonatal foal death, five of which were EHV-1 positive. Maternal factors including age, parity, number of EHV-1 specific vaccinations and the number of days between final vaccination and foaling or abortion were not significantly associated with pregnancy loss. In contrast, a statistically significant association between the presence of the MHC class I B2 allele and pregnancy loss was identified, regardless of the fetus/foal's EHV-1 status (p=0.002). In conclusion, this study demonstrated a significantly positive association between pregnancy loss in Thoroughbred mares and a specific MHC class I allele in the mother. This association requires independent validation and further investigation of the mechanism by which the mare's genetic background contributes to pregnancy outcome.

Seroprevalence and factors associated with equine herpesvirus type 1 and 4 in Spanish Purebred horses in Spain

Equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4) have a worldwide distribution and cause respiratory disease, abortion, neonatal death and myeloencephalopathy in susceptible horses. Given the scarcity of serological EHV-1/EHV-4 data in Spain, the objective of this cross-sectional study was to estimate the seroprevalence of EHV-1/EHV-4 and to identify potential horse-level and stud farm-level factors associated with EHV-1/EHV-4 in the breeding Spanish Purebred (SP) horse population in central Spain. Serum samples from 334 SP unvaccinated horses, collected between September 2011 and November 2013 at 30 stud farms, were tested using a commercially available EHV-1/EHV-4 antibody ELISA and seroneutralisation as the World Organisation for Animal Health reference confirmation test. Data on factors putatively associated with seropositivity to EHV-1/EHV-4 were collected via a questionnaire and examined using logistic regression analysis. EHV-1/EHV-4 seroprevalence in the SP breeding population in central Spain, standardised for the sex distribution of the reference horse population, was 53.9 per cent (95 per cent confidence interval 44.0 per cent to 63.8 per cent). Increasing age, southern location of the stud farm, temperate climate during the summer, and a smaller surface area used for breeding activities in the farm were associated with increased odds for EHV-1/EHV-4 seropositivity, whereas EHV-1/EHV-4 vaccination of other resident horses and separation of breeding mares from youngsters were protective factors.

Decision-tree analysis of clinical data to aid diagnostic reasoning for equine laminitis: a cross-sectional study

The objective of this cross-sectional study was to compare the prevalence of selected clinical signs in laminitis cases and non-laminitic but lame controls to evaluate their capability to discriminate laminitis from other causes of lameness. Participating veterinary practitioners completed a checklist of laminitis-associated clinical signs identified by literature review. Cases were defined as horses/ponies with veterinary-diagnosed, clinically apparent laminitis; controls were horses/ponies with any lameness other than laminitis. Associations were tested by logistic regression with adjusted odds ratios (ORs) and 95% confidence intervals, with veterinary practice as an a priori fixed effect. Multivariable analysis using graphical classification tree-based statistical models linked laminitis prevalence with specific combinations of clinical signs. Data were collected for 588 cases and 201 controls. Five clinical signs had a difference in prevalence of greater than +50 per cent: 'reluctance to walk' (OR 4.4), 'short, stilted gait at walk' (OR 9.4), 'difficulty turning' (OR 16.9), 'shifting weight' (OR 17.7) and 'increased digital pulse' (OR 13.2) (all P<0.001). 'Bilateral forelimb lameness' was the best discriminator; 92 per cent of animals with this clinical sign had laminitis (OR 40.5, P<0.001). If, in addition, horses/ponies had an 'increased digital pulse', 99 per cent were identified as laminitis. 'Presence of a flat/convex sole' also significantly enhanced clinical diagnosis discrimination (OR 15.5, P<0.001). This is the first epidemiological laminitis study to use decision-tree analysis, providing the first evidence base for evaluating clinical signs to differentially diagnose laminitis from other causes of lameness. Improved evaluation of the clinical signs displayed by laminitic animals examined by first-opinion practitioners will lead to equine welfare improvements.

Classification of eating disorders: comparison of relative prevalence rates using DSM-IV and DSM-5 criteria

DSM-5 contains substantial changes to eating disorder diagnoses. We examined relative prevalence rates of DSM-IV and DSM-5 eating disorder diagnoses using Eating Disorder Examination-Questionnaire diagnostic algorithms in 117 community out-patients. DSM-5 criteria produced a reduction in combined 'other specified feeding or eating disorder' and 'unspecified feeding or eating disorder' from 46% to 29%, an increase in anorexia nervosa diagnoses from 35% to 47%, the same number of bulimia nervosa diagnoses and a 5% rate of binge eating disorder diagnoses.

'Help us, she's fading away': How to manage the patient with anorexia nervosa

BACKGROUND

Although integral to the early detection and treatment of anorexia nervosa, there is a paucity of clear guidance available for general practitioners (GPs). This paper attempts to bridge the gap between the specialist and generalist literature to assist the busy GP feel confident in identifying and managing these patients.

OBJECTIVE

On reading this article it is anticipated the GP will feel well equipped to screen for and provide ongoing treatment to patients who pre-sent with eating disorders, particularly anorexia nervosa. This paper provides guidance for the identification and ongoing management of patients with anorexia nervosa, and supporting their carers.

DISCUSSION

People affected by eating disorders, particularly anorexia nervosa, may deny having a problem, minimise their symptoms and resist treatment yet engage partially with their GP throughout the course of their illness. There are well-validated, quick screening tools that the non-specialist can use to identify patients at high risk of having an eating disorder.

A genome-wide association study demonstrates significant genetic variation for fracture risk in Thoroughbred racehorses

Background

Thoroughbred racehorses are subject to non-traumatic distal limb bone fractures that occur during racing and exercise. Susceptibility to fracture may be due to underlying disturbances in bone metabolism which have a genetic cause. Fracture risk has been shown to be heritable in several species but this study is the first genetic analysis of fracture risk in the horse.

Results

Fracture cases (n = 269) were horses that sustained catastrophic distal limb fractures while racing on UK racecourses, necessitating euthanasia. Control horses (n = 253) were over 4 years of age, were racing during the same time period as the cases, and had no history of fracture at the time the study was carried out. The horses sampled were bred for both flat and National Hunt (NH) jump racing. 43,417 SNPs were employed to perform a genome-wide association analysis and to estimate the proportion of genetic variance attributable to the SNPs on each chromosome using restricted maximum likelihood (REML). Significant genetic variation associated with fracture risk was found on chromosomes 9, 18, 22 and 31. Three SNPs on chromosome 18 (62.05 Mb – 62.15 Mb) and one SNP on chromosome 1 (14.17 Mb) reached genome-wide significance (p < 0.05) in a genome-wide association study (GWAS). Two of the SNPs on ECA 18 were located in a haplotype block containing the gene zinc finger protein 804A (ZNF804A). One haplotype within this block has a protective effect (controls at 1.95 times less risk of fracture than cases, p = 1 × 10^-4), while a second haplotype increases fracture risk (cases at 3.39 times higher risk of fracture than controls, p = 0.042).

Conclusions

Fracture risk in the Thoroughbred horse is a complex condition with an underlying genetic basis. Multiple genomic regions contribute to susceptibility to fracture risk. This suggests there is the potential to develop SNP-based estimators for genetic risk of fracture in the Thoroughbred racehorse, using methods pioneered in livestock genetics such as genomic selection. This information would be useful to racehorse breeders and owners, enabling them to reduce the risk of injury in their horses.

Infectious risk factors and clinical indicators for tracheal mucus in British National Hunt racehorses

REASONS FOR PERFORMING STUDY

Many studies of respiratory disease in racehorses have focused on a combination of increased tracheal mucus and airway neutrophilia. Examination of each component separately should provide further insight into this condition.

OBJECTIVES

To identify infectious risk factors for endoscopically visible tracheal mucus in National Hunt racehorses.

STUDY DESIGN

A 2 year prospective longitudinal study.

METHODS

Monthly quantitative bacteriological examinations of tracheal wash samples and viral serological examinations were conducted. Risk factors for 'small amounts of mucus' (mucus score = 1/3) and 'increased mucus' (score ≥2/3) were identified.

RESULTS

There were increased odds of small amounts of mucus when both Streptococcus zooepidemicus and nonhaemolytic streptococci (NHS) were isolated (odds ratio [OR] 2.6; 95% confidence interval [CI] 1.5-4.6; P<0.001) but not when either species was isolated in the absence of the other. Increased odds of increased mucus were associated with the isolation of either S. zooepidemicus (OR 5.6; 95% CI 1.2-25.9; P = 0.03) or NHS (OR 3.7; 95% CI 1.2-11.6; P = 0.02), with an increased effect when both were isolated together (OR 12.5; 95% CI 3.7-41.6; P<0.001). Approximately 6-fold increased odds of small amounts of mucus were associated with the first 3 months in training (OR 6.3; 95% CI 2.0-19.4; P<0.001) and 3-fold increased odds of increased mucus associated with the first 6 months in training (OR 2.9; 95% CI 1.3-6.4; P = 0.01). Coughing at exercise and increased serous nasal discharge were specific but insensitive indicators of increased mucus.

CONCLUSIONS

Associations with S. zooepidemicus corroborate previous research, but an independent effect of NHS has not previously been reported. The possibility that there are individual pathogenic species within this group should be considered. Further work is required to identify S. zooepidemicus subtypes and NHS species associated with disease. Closer monitoring of the respiratory health of horses entering training for the first time is likely to be valuable.

What can mathematical models bring to the control of equine influenza?

Mathematical modelling of infectious disease is increasingly regarded as an important tool in the development of disease prevention and control measures. This article brings together key findings from various modelling studies conducted over the past 10 years that are of relevance to those on the front line of the battle against equine influenza.

The Summary is available in Chinese – see Supporting information.

Preventive health care and owner-reported disease prevalence of horses and ponies in Great Britain

This study aimed to describe the provision of preventive health care and owner-reported disease prevalence in horses and ponies within Great Britain (GB), and to assess geographical variations in health care provision. A cross-sectional survey was conducted, using a postal questionnaire administered to a random sample of veterinary-registered owners of horses and ponies in GB (n=797). The majority of animals received regular preventive health care: 95.6% had regular hoof care; 71.3% were vaccinated for both influenza and tetanus and median time since last anthelmintic administration was 8.7 weeks. Thirty-one percent of owners indicated their animal was overweight/obese. A new health problem within the previous 7 days was reported for 7.4% of animals, 59.3% of which were veterinary-diagnosed. Thirty-two percent of animals were reported to have a long-term/recurrent condition, of which osteoarthritis (13.9%) was the most prevalent. Obesity, musculoskeletal disorders, and dermatological conditions were the most prevalent conditions affecting veterinary-registered horses/ponies.

Duration of equine influenza virus shedding and infectivity in immunised horses after experimental infection with EIV A/eq2/Richmond/1/07

Equine influenza (EI) is a major respiratory disease of horses. Recent outbreaks of EI have demonstrated the ease with which EI virus (EIV) can be transmitted internationally. This study aimed to improve our understanding of EIV shedding after infection of vaccinated horses, which would inform possible changes to current quarantine requirements. Our objectives were to compare commonly used diagnostic tests and to evaluate the relative merits of nasal and nasopharyngeal swabs for detection of EIV in vaccinated and unvaccinated ponies following EIV infection and to use these data to inform optimal quarantine procedures for the safe international movement of horses. Five ponies vaccinated against EI were infected experimentally with A/eq/Richmond/1/07 (Florida clade 2), 11 weeks after V2. Nasal and nasopharyngeal swabs were taken daily for 14 days and every 2 days for another 2 weeks. The 5 vaccinates were introduced sequentially for 48h to 3 groups of 2 naïve sentinel ponies each on days 2, 4 and 6 post-challenge respectively. Clinical signs of disease and EIV shedding were monitored for 14 days after co-mingling. EIV was detected by 3 different methods of detection (EIV nucleoprotein ELISA, EIV nucleoprotein qRT-PCR and isolation/titration in embryonated hens' eggs). Directigen™ EZ Flu A+B tests were also performed on samples from the vaccinated ponies for 6 days after infection. Results show that nasopharyngeal swabs were superior to nasal swabs, with increased frequency and amount of virus detected. The average mean duration of shedding was 6-8 days in naïve animals. All 3 sentinel groups were infected successfully with EIV after commingling with vaccinates, indicating up to 6 days of transmission. EI protection induced by vaccination is a dynamic process, naturally fluctuating and dependent on the time since last immunisation, with periods of high immunity (peak of immunity shortly after boost immunisation) and periods of susceptibility to EIV infection. This result indicates that vaccinated horses may actively transmit EIV if the immunity gap (a usual period of susceptibility between V2 and V3) is not adequately closed by immunisation. In infected sentinels EIV was detectable up to 12 days after commingling. Results also suggest that tests such as qRT-PCR may be a suitable substitute for time spent in pre-export quarantine.

Where are the horses? With the sheep or cows? Uncertain host location, vector-feeding preferences and the risk of African horse sickness transmission in Great Britain

Understanding the influence of non-susceptible hosts on vector-borne disease transmission is an important epidemiological problem. However, investigation of its impact can be complicated by uncertainty in the location of the hosts. Estimating the risk of transmission of African horse sickness (AHS) in Great Britain (GB), a virus transmitted by Culicoides biting midges, provides an insightful example because: (i) the patterns of risk are expected to be influenced by the presence of non-susceptible vertebrate hosts (cattle and sheep) and (ii) incomplete information on the spatial distribution of horses is available because the GB National Equine Database records owner, rather than horse, locations. Here, we combine land-use data with available horse owner distributions and, using a Bayesian approach, infer a realistic distribution for the location of horses. We estimate the risk of an outbreak of AHS in GB, using the basic reproduction number (R0), and demonstrate that mapping owner addresses as a proxy for horse location significantly underestimates the risk. We clarify the role of non-susceptible vertebrate hosts by showing that the risk of disease in the presence of many hosts (susceptible and non-susceptible) can be ultimately reduced to two fundamental factors: first, the abundance of vectors and how this depends on host density, and, second, the differential feeding preference of vectors among animal species.

Equine influenza--a global perspective

To date, equine influenza outbreaks have been reported all over the world with the exception of a small number of island nations including New Zealand and Iceland. Influenza is endemic in Europe and North America and is considered to be of potentially major economic significance to the equine industry worldwide. The importation of subclinically infected vaccinated horses, and inadequate quarantine procedures have resulted in several major outbreaks in susceptible populations for example, in Australia (2007) when more than 76,000 horses on over 10,000 properties were reported as infected. This review summarises the current understanding of, and recent research on, equine influenza, including epidemiology, pathogenesis, clinical characteristics, laboratory diagnosis, management and prevention. Recent advances in diagnostic techniques are discussed as are the merits of different vaccination regimes.

Transmission of equine influenza virus during an outbreak is characterized by frequent mixed infections and loose transmission bottlenecks

The ability of influenza A viruses (IAVs) to cross species barriers and evade host immunity is a major public health concern. Studies on the phylodynamics of IAVs across different scales – from the individual to the population – are essential for devising effective measures to predict, prevent or contain influenza emergence. Understanding how IAVs spread and evolve during outbreaks is critical for the management of epidemics. Reconstructing the transmission network during a single outbreak by sampling viral genetic data in time and space can generate insights about these processes. Here, we obtained intra-host viral sequence data from horses infected with equine influenza virus (EIV) to reconstruct the spread of EIV during a large outbreak. To this end, we analyzed within-host viral populations from sequences covering 90% of the infected yards. By combining gene sequence analyses with epidemiological data, we inferred a plausible transmission network, in turn enabling the comparison of transmission patterns during the course of the outbreak and revealing important epidemiological features that were not apparent using either approach alone. The EIV populations displayed high levels of genetic diversity, and in many cases we observed distinct viral populations containing a dominant variant and a number of related minor variants that were transmitted between infectious horses. In addition, we found evidence of frequent mixed infections and loose transmission bottlenecks in these naturally occurring populations. These frequent mixed infections likely influence the size of epidemics.

Influenza A viruses (IAVs) are major pathogens of humans and animals. Understanding how IAVs spread and evolve at different scales (individual, regional, global) in natural conditions is critical for preventing or managing influenza epidemics. A vast body of knowledge has been generated on the evolution of IAVs at the global scale. Additionally, recent experimental transmission studies have examined the diversity and transmission of influenza viruses within and between hosts. However, most studies on the spread of IAVs during epidemics have been based on consensus viral sequences, an approach that does not have enough discriminatory power to reveal exact transmission pathways. Here, we analyzed multiple within-host viral populations from different horses infected with equine influenza virus (EIV) during the course of an outbreak in a population within a confined area. This provided an opportunity to examine the genetic diversity of the viruses within single animals, the transmission of the viruses between each closely confined population within a yard, and the transmission between horses in different yards. We show that individual horses can be infected by viruses from more than one other horse, which has important implications for facilitating segment reassortment and the evolution of EIV. Additionally, by combining viral sequencing data and epidemiological data we show that the high levels of mixed infections can reveal the underlying epidemiological dynamics of the outbreak, and that epidemic size could be underestimated if only epidemiological data is considered. As sequencing technologies become cheaper and faster, these analyses could be undertaken almost in real-time and help control future outbreaks.

An investigation of risk factors for foot-related lameness in a United Kingdom referral population of horses

Lameness relating to the foot of the horse is common, but the majority of information concerning risk factors for injury is anecdotal. The objectives of this study were to investigate risk factors for foot-related pain in a referral population of horses, with particular reference to injury/disease of the podotrochlear apparatus (PTA), by comparison with the remainder of the clinic population. It was hypothesised that there would be an increased risk of foot pain associated with breed, work discipline, age, height and bodyweight (BW). A retrospective study of all horses examined at a referral centre between 2001 and 2010 was performed using univariable and multivariable logistic regression analyses. There were 4618 horses investigated, 1132 of which had foot pain. There was increased risk of foot pain in multivariable analyses (all categories combined) in horses aged 6-9 and 10-15 years (OR = 1.60 and 1.72, respectively), compared with horses <6 years old, in show jumpers (OR = 1.44) compared with dressage horses, Thoroughbred cross-breeds (OR = 1.53) compared with Warmbloods and in horses with a BW:height ratio in the upper two quartiles (3.45-3.71 or >3.71; OR = 1.55 and 1.44, respectively), compared with the lowest quartile (<3.19). Racehorses had reduced risk for all types of foot pain combined (OR = 0.13) compared with dressage horses. Risk factors for PTA injury were age (10-15 years, OR = 2.12; >15 years, OR = 3.36, compared with <6 years old), BW:height ratio (>3.45-3.71 (OR = 2.75), >3.71 (OR = 2.06), compared with <3.19) and Thoroughbred cross-breed (OR = 1.73) compared with Warmbloods. Show jumpers had an increased risk of PTA and other injuries (OR = 2.29) when compared with dressage horses. Age, breed, work discipline and BW:height ratio influenced the risk of foot pain, but other factors probably also play a role.

Detection of Streptococcus equi subspecies equi using a triplex qPCR assay

Genome sequencing data for Streptococcus equi subspecies equi and zooepidemicus were used to develop a novel diagnostic triplex quantitative PCR (qPCR) assay targeting two genes specific to S. equi (eqbE and SEQ2190) and a unique 100 base pair control DNA sequence (SZIC) inserted into the SZO07770 pseudogene of S. zooepidemicus strain H70. This triplex strangles qPCR assay can provide results within 2 h of sample receipt, has an overall sensitivity of 93.9% and specificity of 96.6% relative to the eqbE singlex assay and detects S. equi at levels below the threshold of the culture assay, even in the presence of contaminating bacteria.

Risk factors for superficial digital flexor tendinopathy in Thoroughbred racehorses in steeplechase starts in the United Kingdom (2001-2009)

The objective of this study was to identify risk factors for superficial digital flexor (SDF) tendinopathy in Thoroughbred horses in steeplechase races in the United Kingdom. Potential risk factors for SDF tendinopathy were studied between 1st January 2001 and 31st December 2009 using a cohort study design with 648 injuries sustained in 102,894 starts. Potential risk factors were screened using univariable logistic regression prior to multivariable model building. In the final multivariable model, 12 statistically significant risk factors were identified. Variables that increased the odds of SDF tendinopathy included firmer going, increased horse age, and racing in the summer compared to other seasons. Variables that decreased the odds included having a higher official rating and the number of starts in the preceding days. Fewer and different risk factors were identified than in an equivalent model of SDF tendinopathy in hurdle racing, highlighting potential differences between these disciplines. Further collection of training and racecourse information would be beneficial and may help to explain further some of the associations identified in this study. The results will facilitate the development of strategies to improve overall safety of horses in UK steeplechase racing.

The gene expression response of the catadromous perciform barramundi Lates calcarifer to an acute heat stress

The acute heat-shock response of the tropical estuarine fish species barramundi Lates calcarifer as indicated by the expression of genes within stress (hsp 90AA, hsp 90AB, hsp 70 and hsc 70), metabolic (cisy, cco II and ldh) and growth (igf1 and mstn 1) related pathways was examined following an increase in water temperature from 28 to 36° C over 30 min. Lates calcarifer were maintained at the acute stress temperature of 36° C for 1 h before being returned to 28° C and allowed to recover at this temperature for a further 2 weeks. Muscle tissue sampling over the experimental period allowed for the expression quantification of stress, metabolic and growth-related genes via quantitative real-time polymerase chain reaction (qrt-PCR) where a robust and reliable normalization approach identified both α-tub and Rpl8 as appropriate genes for the analysis of gene expression in response to an acute heat stress. hsp90AA and hsp70 of the inducible heat-shock response pathway showed a massive up-regulation of gene expression in response to heat stress, whilst the constitutive heat-shock genes hsp90AB and hsp70 showed no change over the course of the experiment and a small increase after 2 weeks of recovery, respectively. Of the three genes representing the metabolic pathway (cisy, cco II and ldh) only cco II changed significantly showing a decrease in gene expression, which may suggest a small suppression of aerobic metabolism. igf1 of the growth pathway showed no significant differences in response to an acute heat stress, whilst mstn1 increased at the beginning of the heat stress but returned to basal levels soon after. Overall, the results demonstrate that an acute heat stress in L. calcarifer caused a significant increase in the expression of genes from the stress response pathway and a possible decrease in aerobic metabolism with only relatively minor changes to the growth pathway highlighting the hardy nature of L. calcarifer and its resilience in coping with sudden temperature changes routinely encountered within its natural environment.

A genome-wide association study of osteochondritis dissecans in the Thoroughbred

Osteochondrosis is a developmental orthopaedic disease that occurs in horses, other livestock species, companion animal species, and humans. The principal aim of this study was to identify quantitative trait loci (QTL) associated with osteochondritis dissecans (OCD) in the Thoroughbred using a genome-wide association study. A secondary objective was to test the effect of previously identified QTL in the current population. Over 300 horses, classified as cases or controls according to clinical findings, were genotyped for the Illumina Equine SNP50 BeadChip. An animal model was first implemented in order to adjust each horse's phenotypic status for average relatedness among horses and other potentially confounding factors which were present in the data. The genome-wide association test was then conducted on the residuals from the animal model. A single SNP on chromosome 3 was found to be associated with OCD at a genome-wide level of significance, as determined by permutation. According to the current sequence annotation, the SNP is located in an intergenic region of the genome. The effects of 24 SNPs, representing QTL previously identified in a sample of Hanoverian Warmblood horses, were tested directly in the animal model. When fitted alongside the significant SNP on ECA3, two of these SNPs were found to be associated with OCD. Confirmation of the putative QTL identified on ECA3 requires validation in an independent sample. The results of this study suggest that a significant challenge faced by equine researchers is the generation of sufficiently large data sets to effectively study complex diseases such as osteochondrosis.

Molecular epidemiology of strangles outbreaks in the UK during 2010

The sequence of the Streptococcus equi subspecies equi (S equi) M-like protein (SeM) gene was determined for 105 isolates of S equi from strangles outbreaks in the UK during 2010 and compared with previous data from 2007 to 2008. Twenty-three distinct alleles were identified, including 11 novel alleles. One allele giving rise to a putative truncated M protein was identified from the guttural pouch of an asymptomatic carrier. Allele 9 was the most prevalent, comprising 57.7 per cent of isolates, followed by allele 6 (10.3 per cent). Significant changes in allele prevalence were found between 2007, 2008 and 2010, with an increasing prevalence in SeM-9-related alleles and a corresponding decreasing prevalence in SeM-6-related alleles observed over the period (P<0.001). Geographical proximity of outbreaks caused by some uncommon alleles was apparent between 2007, 2008 and 2010.