Characterization of an outbreak of equine coronavirus infection in adult horses in Switzerland.

INTRODUCTION: Outbreaks of equine coronavirus (ECoV) infections have been described in different parts of the world including Europe. The aim of this report was to describe clinical signs, diagnostic work-up and outcome of the first documented outbreak of ECoV in Switzerland in order to raise the awareness for the disease and its various clinical presentations. The outbreak occurred on a farm with 26 horses. Of these, seven horses developed clinical disease ranging from mild signs such as fever and anorexia to severe signs of acute colitis. One horse died due to severe endotoxemia and circulatory shock secondary to severe acute necrotizing enteritis and colitis. Out of the 26 horses, five horses tested positive for ECoV, including two ponies without any clinical signs of infection. The low number of positive cases should nevertheless be interpreted with caution as testing was only performed on one occasion, over a month after the onset of clinical signs in the first suspected case. This report highlights the importance of diagnostic testing and early implementation of biosecurity measures on a farm with an ECoV outbreak. It should furthermore raise the awareness for unspecific and mild clinical signs such as fever and anorexia in affected animals that are potentially able to spread the disease.

INTRODUCTION: Des foyers d'infection à coronavirus équin (ECoV) ont été décrits dans différentes parties du monde, y compris en Europe. L'objectif de ce rapport est de décrire les signes cliniques, le diagnostic et les conséquences du premier foyer d'ECoV documenté en Suisse, afin de sensibiliser le public à cette maladie et à ses différents aspects cliniques. L'épidémie s'est produite dans une écurie comptant 26 chevaux. Parmi ceux-ci, sept chevaux ont développé une forme clinique allant de signes légers tels que la fièvre et l'anorexie à des signes sévères de colite aiguë. Un cheval est mort en raison d'une endotoxémie sévère et d>un choc circulatoire secondaire à une entérite nécrosante aiguë sévère et à une colite. Sur les 26 chevaux, cinq ont été testés positifs à l>ECoV, dont deux poneys sans aucun signe clinique d'infection. Le faible nombre de cas positifs doit néanmoins être interprété avec prudence car les tests n'ont été effectués qu'à une seule occasion, plus d'un mois après l'apparition des signes cliniques chez le premier cas suspect. Ce rapport souligne l'importance des tests de diagnostic et de la mise en œuvre rapide de mesures de biosécurité dans une exploitation où un foyer d'ECoV est détecté. Il devrait en outre sensibiliser à la présence de signes cliniques peu spécifiques et bénins tels que la fièvre et l'anorexie chez les animaux atteints qui sont potentiellement capables de propager la maladie.

Factors Associated with Colostrum Quality and Effects on Serum Gamma Globulin Concentrations of Calves in Swiss Dairy Herds.

BACKGROUND: Previous studies have shown a high prevalence of failure of passive transfer of immunity (FPT) in Swiss dairy calves. OBJECTIVES: To investigate risk factors associated with poor colostrum quality and FPT on Swiss dairy farms. ANIMALS: Colostrum and serum samples from 373 dam-calf pairs at 141 farms. METHODS: The gamma globulin (Gg) concentrations of the dams' colostrum and the calves' serum samples were determined by electrophoresis. Potential risk factors were assessed by logistic regression of questionnaire data. RESULTS: Prevalence values of 15.5% (95% confidence interval [CI], 12.0-19.6%) for low-quality colostrum (<50 g Gg/L) in cows and 43.5% (95% CI, 38.4-48.8%) for FPT (serum Gg < 10 g/L) in calves were estimated. The main factors associated with low colostrum quality included colostrum leakage before or during parturition and a time lag > 6 hours between parturition and first milking. The results confirm that the occurrence of FPT in calves primarily was influenced by the quality of colostrum, the amount of ingested colostrum, and the time between birth and first feeding. CONCLUSIONS AND CLINICAL IMPORTANCE: These results confirm a large potential for improvement in colostrum harvesting and colostrum feeding procedures in the study herds. Control for colostrum leaking intra-partum, early colostrum milking, and ensuring that the calves ingest a sufficient volume of colostrum within the first hours of life are measures that can be readily implemented by farmers to decrease the incidence of FPT without additional workload.

Clinical course of sarcoids in 61 Franches-Montagnes horses over a 5-7 year period.

BACKGROUND: The progression of equine sarcoids (ES) is notoriously unpredictable. Making a choice for the appropriate treatment is challenging when dealing with milder manifestations of ES. OBJECTIVE: The aim of this study was to investigate the clinical course of ES in young horses. ANIMALS AND METHODS: A cohort of 61 ES-affected three-year-old Franches-Montagnes horses and a breed-, age- and geographically matched control group of 75 ES-free peers were examined twice over a period of 5-7 years. Owners and caretakers were queried, using a standardized questionnaire. RESULTS: More than half of the 38/61 (62%) horses that were ES-affected at the age of three, had become ES-free at the time of follow-up. In 29 of 38 horses, representing 48% of the entire study population, ES lesions had spontaneously disappeared without therapy. When differentiating the clinical types of ES lesions, occult ES underwent complete spontaneous regression in 65% (11/17), while verrucous lesions regressed spontaneously in 32% (9/28). None of the evaluated intrinsic or environmental factors showed a significant effect on the risk for development, regression or exacerbation of ES disease. CONCLUSIONS: Our results document a surprisingly high rate of spontaneous ES regression for young horses affected with milder manifestations of ES disease. These findings justify a 'wait-and-see' approach in selected cases of occult and verrucous ES, provided that all lesions are closely monitored. Furthermore, results of this study should also be considered when critically assessing treatment effects of therapies directed against ES, especially in the context of uncontrolled studies.

Experiences with a voluntary surveillance system for early detection of equine diseases in Switzerland.

Clinical observations made by practitioners and reported using web- and mobile-based technologies may benefit disease surveillance by improving the timeliness of outbreak detection. Equinella is a voluntary electronic reporting and information system established for the early detection of infectious equine diseases in Switzerland. Sentinel veterinary practitioners have been able to report cases of non-notifiable diseases and clinical symptoms to an internet-based platform since November 2013. Telephone interviews were carried out during the first year to understand the motivating and constraining factors affecting voluntary reporting and the use of mobile devices in a sentinel network. We found that non-monetary incentives attract sentinel practitioners; however, insufficient understanding of the reporting system and of its relevance, as well as concerns over the electronic dissemination of health data were identified as potential challenges to sustainable reporting. Many practitioners are not yet aware of the advantages of mobile-based surveillance and may require some time to become accustomed to novel reporting methods. Finally, our study highlights the need for continued information feedback loops within voluntary sentinel networks.

Retrospective evaluation of all recorded horse race starts in Switzerland during a four year period focusing on discipline-specific risk factors for clinical events.

REASONS FOR PERFORMING STUDY: Racetrack injuries are of welfare concern and the prevention of injuries is an important goal in many racing jurisdictions. Over the years this has led to more detailed recording of clinical events on racecourses. However, risk factor analyses of clinical events at race meetings have not been previously reported for Switzerland. OBJECTIVES: To identify discipline-specific factors that influence the occurrence of clinical events during race meetings with the ultimate aim of improving the monitoring and safety of racetracks in Switzerland and optimising racehorse welfare. STUDY DESIGN: Retrospective study of horse race data collected by the Swiss horse racing association. METHODS: All race starts (n = 17,670, including 6198 flat, 1257 obstacle and 10,215 trot race starts) recorded over a period of 4 years (2009-2012) were analysed in multivariable mixed effect logistic regression models including horse and racecourse related data. The models were designed to identify discipline-specific factors influencing the occurrence of clinical events on racecourses in Switzerland. RESULTS: Factors influencing the risk of clinical events during races were different for each discipline. The risk of a clinical event in trot racing was lower for racing on a Porphyre sand track than on grass tracks. Horses whose driver was also their trainer had an approximately 2-fold higher risk for clinical events. In obstacle races, longer distances (2401-3300 m and 3301-5400 m, respectively) had a protective effect compared with racing over shorter distances. In flat racing, 5 racecourses reported significantly fewer clinical events. In all 3 disciplines, finishing 8th place or later was associated with clinical events. CONCLUSIONS: Changes in management that aim to improve the safety and welfare of racehorses, such as racetrack adaptations, need to be individualised for each discipline.

A multiarm randomized field trial evaluating strategies for udder health improvement in Swiss dairy herds.

The aims of this study were to quantify the effectiveness of specialist advice about udder health in Swiss dairy herds and to compare 3 different udder health improvement strategies against a negative control group. In 2010, 100 Swiss dairy herds with a high (between 200,000 and 300,000 cells/mL) yield-corrected bulk milk somatic cell count (YCBMSCC) were recruited for a 1-yr multiarm randomized field trial. The herds were visited between September and December 2011 to evaluate udder health-management practices and then randomly allocated into 1 of 4 study arms containing 25 herds each. The negative control study arm received neither recommendations for improving udder health nor any active support. The remaining 75 farmers received a herd-specific report with recommendations to improve udder health management. The positive control study arm received no further active support during 2012. The veterinarian study arm received additional support in the form of monthly visits by their herd veterinarian. Finally, the study group study arm received support in the form of bimonthly study group meetings where different topics concerning udder health were discussed. One year later, implementation of recommendations and changes in udder health were assessed. Of the recommendations given, 44.3% were completely implemented, 23.1% partially, and 32.6% were not implemented. No differences in implementation of recommendations were noted between the 3 study arms. At study enrollment, farmers were asked for the study arm of their preference but were subsequently randomly assigned to 1 of the 4 study arms. Farmers that were assigned to the study arm of their preference implemented more recommendations than farmers assigned to a study arm not of their preference. No decrease in the within-herd prevalence of cows that had a high (≥200,000 cells/mL) composite somatic cell count was observed in herds that had a YCBMSCC ≥200,000 cells/mL at the start of intervention. However, the 3 study arms with intervention (positive control, the veterinarian, and the study groups) prevented an increase in the within-herd prevalence of cows that had a high somatic cell count in herds with a low YCBMSCC at the start of the intervention compared with the negative control study arm. In the year after sending the report, herds assigned to the study group study arm had a reduced incidence rate of treated mastitis cases in comparison with the year before sending the report.

International online survey to assess current practice in equine anaesthesia.

REASONS FOR PERFORMING STUDY: Multicentre Confidential Enquiries into Perioperative Equine Fatalities (CEPEF) have not been conducted since the initial CEPEF Phases 1-3, 20 years ago. OBJECTIVES: To collect data on current practice in equine anaesthesia and to recruit participants for CEPEF-4. STUDY DESIGN: Online questionnaire survey. METHODS: An online questionnaire was prepared and the link distributed internationally to veterinarians possibly performing equine anaesthesia, using emails, posters, flyers and an editorial. The questionnaire included 52 closed, semiclosed and open questions divided into 8 subgroups: demographic data, anaesthetist, anaesthesia management (preoperative, technical equipment, monitoring, drugs, recovery), areas of improvements and risks and motivation for participation in CEPEF-4. Descriptive statistics and Chi-squared tests for comparison of categorical variables were performed. RESULTS: A total of 199 questionnaires were completed by veterinarians from 14 different countries. Of the respondents, 43% worked in private hospitals, 36% in private practices and 21% in university teaching hospitals. In 40 institutions (23%) there was at least one diplomate of the European or American colleges of veterinary anaesthesia and analgesia on staff. Individual respondents reported routinely employ the following anaesthesia monitoring modalities: electrocardiography (80%), invasive arterial blood pressures (70%), pulse oximetry (60%), capnography (55%), arterial blood gases (47%), composition of inspired and expired gases (45%) and body temperature (35%). Drugs administered frequently or routinely as part of a standard protocol were: acepromazine (44%), xylazine (68%), butorphanol (59%), ketamine (96%), diazepam (83%), isoflurane (76%), dobutamine (46%), and, as a nonsteroidal anti-inflammatory drug, phenylbutazone (73%) or flunixin meglumine (66%). Recovery was routinely assisted by 40%. The main factors perceived by the respondents to affect outcome of equine anaesthesia were the preoperative health status of the animal and training of the anaesthetist. CONCLUSIONS: Current practice in equine anaesthesia varies widely, and the study has highlighted important topics relevant for designing a future prospective multicentre cohort study (CEPEF-4). The Summary is available in Chinese - see Supporting information.

Genotype-specific risk factors for Staphylococcus aureus in Swiss dairy herds with an elevated yield-corrected herd somatic cell count.

Bovine mastitis is a frequent problem in Swiss dairy herds. One of the main pathogens causing significant economic loss is Staphylococcus aureus. Various Staph. aureus genotypes with different biological properties have been described. Genotype B (GTB) of Staph. aureus was identified as the most contagious and one of the most prevalent strains in Switzerland. The aim of this study was to identify risk factors associated with the herd-level presence of Staph. aureus GTB and Staph. aureus non-GTB in Swiss dairy herds with an elevated yield-corrected herd somatic cell count (YCHSCC). One hundred dairy herds with a mean YCHSCC between 200,000 and 300,000cells/mL in 2010 were recruited and each farm was visited once during milking. A standardized protocol investigating demography, mastitis management, cow husbandry, milking system, and milking routine was completed during the visit. A bulk tank milk (BTM) sample was analyzed by real-time PCR for the presence of Staph. aureus GTB to classify the herds into 2 groups: Staph. aureus GTB-positive and Staph. aureus GTB-negative. Moreover, quarter milk samples were aseptically collected for bacteriological culture from cows with a somatic cell count ≥150,000cells/mL on the last test-day before the visit. The culture results allowed us to allocate the Staph. aureus GTB-negative farms to Staph. aureus non-GTB and Staph. aureus-free groups. Multivariable multinomial logistic regression models were built to identify risk factors associated with the herd-level presence of Staph. aureus GTB and Staph. aureus non-GTB. The prevalence of Staph. aureus GTB herds was 16% (n=16), whereas that of Staph. aureus non-GTB herds was 38% (n=38). Herds that sent lactating cows to seasonal communal pastures had significantly higher odds of being infected with Staph. aureus GTB (odds ratio: 10.2, 95% CI: 1.9-56.6), compared with herds without communal pasturing. Herds that purchased heifers had significantly higher odds of being infected with Staph. aureus GTB (rather than Staph. aureus non-GTB) compared with herds without purchase of heifers. Furthermore, herds that did not use udder ointment as supportive therapy for acute mastitis had significantly higher odds of being infected with Staph. aureus GTB (odds ratio: 8.5, 95% CI: 1.6-58.4) or Staph. aureus non-GTB (odds ratio: 6.1, 95% CI: 1.3-27.8) than herds that used udder ointment occasionally or regularly. Herds in which the milker performed unrelated activities during milking had significantly higher odds of being infected with Staph. aureus GTB (rather than Staph. aureus non-GTB) compared with herds in which the milker did not perform unrelated activities at milking. Awareness of 4 potential risk factors identified in this study guides implementation of intervention strategies to improve udder health in both Staph. aureus GTB and Staph. aureus non-GTB herds.

Diseases in neonatal foals. Part 1: the 30 day incidence of disease and the effect of prophylactic antimicrobial drug treatment during the first three days post partum.

REASONS FOR PERFORMING STUDY: Neonatal diseases have been grouped and analysed but up-to-date statistically significant information about the incidence and prevalence of diseases in foals is limited. Since the 1950s it has been a common management practice to administer a 3 day course of antimicrobial drugs to neonatal foals. This was shown to significantly reduce the incidence of infections (Platt 1977). Since then management practices have improved and it is widely believed that prophylactic antimicrobial drugs are no longer necessary in foal rearing. OBJECTIVES: To determine the 30 day incidences or prevalences (depending on case definition) of various diseases and conditions in the neonatal foal and ascertain the influence of a prophylactic 3 day treatment on the frequency of infections. METHODS: The population consisted of Thoroughbred foals born on stud farms in the Newmarket (UK) area in 2005 (n = 1031). Depending on the stud farm's practice in the use of prophylactic antimicrobial drugs, 2 groups of newborn foals (treated and untreated) were identified and followed for 30 days. RESULTS: The 30 day incidences of infectious diseases under study were between 0.2% (osteomyelitis) and 5.85% (systemic disease with diarrhoea). The overall incidence for 'total infectious diseases' was 8.27%. The most commonly observed noninfectious condition was limb deformities (12.11% of all foals). There was no significant difference in the incidence of infectious diseases between the 2 groups. CONCLUSION: Infectious diseases are still an important problem in neonatal foals requiring further investigation as to which factors other than antimicrobial prophylaxis are relevant for disease prevention. POTENTIAL RELEVANCE: The results provide an up-to-date overview about the frequencies of various neonatal foal diseases. They do not support the traditional prophylactic use of antimicrobials to prevent infectious diseases in healthy newborn foals. However, it should be noted that this study was not a randomised controlled trial and therefore does not provide the strongest possible evidence for this conclusion.

Diseases in neonatal foals. Part 2: potential risk factors for a higher incidence of infectious diseases during the first 30 days post partum.

REASON FOR PERFORMING STUDY: The development of clinical illness in foals is usually predetermined by perinatal history, management or stressful environmental conditions. OBJECTIVES: To determine potential risk factors for an increased incidence of infectious diseases during the first 30 days post partum. METHODS: The population consisted of Thoroughbred foals born on stud farms in the Newmarket (UK) area in 2005 (n = 1031). They were followed for their first 30 days. Factors suspected to influence the incidence of infectious neonatal diseases were examined in a logistic regression approach for each of the 3 outcomes (total infectious diseases, systemic disease with diarrhoea and total infectious diseases excluding diarrhoea). All 28 factors were either foal or mare or stud farm related. RESULTS: Several significant risk factors for a higher disease incidence, such as birth complications, colostrum intake by stomach tube and leucocytosis 12-48 h post partum were identified. The factor 'boarding stud' seemed to be protective against disease. CONCLUSION: Some factors, such as the mare's time at stud before foaling, the mare's rotavirus vaccination schedule and fibrinogen-values that empirically had been linked to the outcome previously were not confirmed as relevant. This included the reported useful prophylactic treatment with antimicrobial drugs. POTENTIAL RELEVANCE: Factors to be considered when evaluating newborn foals include: stud management, the birth process, route of colostrum intake, white and red blood cells, and the date of birth. These may help to detect foals at risk to develop an infection so that targeted prophylactic measures can be initiated.