Diagnostic testing patterns for Streptococcus equi subsp. equi in Ontario horses during the years 2008 to 2018.

This retrospective study describes testing patterns and the incidence of Streptococcus equi subsp. equi in Ontario to assess the utility of laboratory data for surveillance purposes. Laboratory records for equine infectious disease test submissions were extracted from the Animal Health Laboratory (AHL) at the University of Guelph for the years 2008 to 2018. Yearly and seasonal trends in S. equi testing and the proportion of tests that returned positive results were assessed. The number of samples submitted for S. equi testing decreased over the 11-year period (odds ratio = 0.96, 95% confidence interval: 0.92 to 0.999; P = 0.04). A generalized linear model identified a significant seasonal effect for animals recognized as clinically ill, with the highest test positivity noted in the winter. Although this study identified important trends in the incidence of S. equi in Ontario, the variability in information accompanying test submissions made the data challenging to interpret, highlighting the need for more complete diagnostic submission data for S. equi.

Tendance des tests diagnostiques pour Streptococcus equi subsp. equi chez les chevaux de l'Ontario au cours des années 2008 à 2018. Cette étude rétrospective décrit les tendances des test et l'incidence de Streptococcus equi subsp. equi en Ontario pour évaluer l'utilité des données de laboratoire à des fins de surveillance. Les dossiers de laboratoire pour les soumissions de tests de maladies infectieuses équines ont été extraits des données du Animal Health Laboratory (AHL), University of Guelph pour les années 2008 à 2018. Les tendances annuelles et saisonnières des tests de S. equi et la proportion de tests qui ont donné des résultats positifs ont été évaluées. Le nombre d'échantillons soumis pour la recherche de S. equi a diminué au cours de la période de 11 ans (rapport de cotes = 0,96, intervalle de confiance à 95% : 0,92 à 0,999; P = 0,04). Un modèle linéaire généralisé a identifié un effet saisonnier significatif pour les animaux reconnus comme cliniquement malades, la positivité de test la plus élevée étant notée en hiver. Bien que cette étude ait identifié des tendances importantes dans l'incidence de S. equi en Ontario, la variabilité des informations accompagnant les soumissions a rendu les données difficiles à interpréter, soulignant le besoin de données plus complètes lors de soumission pour le diagnostic S. equi.(Traduit par Dr Serge Messier).

Descriptive network analysis of a Standardbred horse training facility contact network: Implications for disease transmission.

Infectious respiratory disease is a common cause of morbidity among racehorses. Quantification of contact patterns in training facilities could help inform disease prevention strategies. The study objectives were to: i) describe the contact network among horses, locations, and humans at a Standardbred horse training facility in Ontario; ii) describe the characteristics of highly influential individuals; and iii) investigate how management changes alter the network metrics and discuss the potential implications for disease transmission. Proximity loggers detected contacts among horses, staff, and locations (n = 144). Network metrics and node centrality measures were described for a 2-mode and horse-only contact network. The 2-mode network density was 0.16. and the median node degree was 20 [interquartile range (IQR) = 12 to 27]. Yearlings and floating staff were most influential in the network suggesting biosecurity programs should emphasize reducing contacts in these groups. Removing highly influential staff or co-housing of age groups resulted in changes to network diameter and density.

Analyse descriptive du réseau de contacts d'un centre d'entraînement de chevaux Standardbred : Implications pour la transmission de maladies. Les maladies respiratoires infectieuses sont une cause commune de morbidité parmi les chevaux de course. Une quantification des patrons de contact dans les centres d'entraînement pourrait aider à avoir des stratégies appropriées de prévention des maladies. Les objectifs de la présente étude étaient de : i) décrire le réseau des contacts entre les chevaux, les localisations et les humains à un centre d'entraînement pour chevaux Stadardbred en Ontario; ii) décrire les caractéristiques d'individus très influents; iii) examiner comment les changements de gestion altèrent le réseau des systèmes de mesure et discuter les implications potentielles pour la transmission des maladies. Des enregistreurs de proximité détectèrent les contacts parmi les chevaux, le personnel et les localisations (n = 144). Les systèmes de mesure et les mesures de centralité des noeuds furent décrits pour un réseau à 2 modes et un réseau de contact entre chevaux uniquement. La densité du réseau à 2 modes était de 0,16 et le degré médian du noeud était 20 [écart interquartile (IQR) = 12 à 27]. Les yearlings et le personnel occasionnel étaient les plus influents dans le réseau suggérant que les programmes de biosécurité devraient mettre l'emphase sur une réduction des contacts dans ces groupes. Le retrait de personnel très influent ou cohabitation de groupes d'âge a résulté en des changements dans le diamètre et la densité du réseau.(Traduit par Dr Serge Messier).

Equine Rhinitis A Virus Infection at a Standardbred Training Facility: Incidence, Clinical Signs, and Risk Factors for Clinical Disease.

Respiratory disease is a common morbidity of young racehorses. Infections can lead to compromised welfare, and economic loss. Identification of risk factors for infection through clinical signs monitoring and collection of demographic, serologic, and contact network data can aid in the development of prevention and control strategies. The study objectives were to: (1) describe the transmission and clinical course of infectious respiratory disease in standardbred racehorses in a multi-barn training facility and, (2) identify demographic, serological, and contact network risk factors associated with Equine Rhinitis A virus (ERAV) respiratory disease. The study population included standardbred racehorses (age 1-5 years: n = 96) housed at a multi-barn training facility in southern Ontario. Clinical signs were monitored daily over a 41-day period in fall 2017. Descriptive statistics, including incidence rate, prevalence and incidence risk were calculated for the observed period. Associations between demographic, serologic, and contact pattern variables, and clinical disease status were investigated using multivariable logistic regression. Respiratory disease cases were characterized by mucopurulent discharge (100%), intermittent cough (37.7%), and ocular discharge (62.3%). Fever (>38.5°C) and inappetence were rarely reported (15.2 and 3.8%). Seroconversion to ERAV among cases was 75%. Total, and yearling-specific incidence risks were 52.5 and 87.9%. The cumulative incidence was 0.027 new cases/horse day. A negative association (OR = 0.011) between increasing age and respiratory disease was significant (p = < 0.001) in the final regression model. Yearling horses were at increased risk of infectious respiratory disease as demonstrated by the high yearling-specific incidence risk, and the negative association between age and infection. Disease control strategies, such as vaccination programs and isolation of new horses arriving from auction, should be targeted at young animals entering training facilities.

Non-antibiotic approaches for disease prevention and control in beef and veal production: a scoping review.

Livestock producers are encouraged to reduce the use of antibiotics belonging to classes of medical importance to humans. We conducted a scoping review on non-antibiotic interventions in the form of products or management practices that could potentially reduce the need for antibiotics in beef and veal animals living under intensive production conditions. Our objectives were to systematically describe the research on this broad topic, identify specific topics that could feasibly support systematic reviews, and identify knowledge gaps. Multiple databases were searched. Two reviewers independently screened and charted the data. From the 13,598 articles screened, 722 relevant articles were charted. The number of relevant articles increased steadily from 1990. The Western European research was dominated by veal production studies whereas the North American research was dominated by beef production studies. The interventions and outcomes measured were diverse. The four most frequent interventions included non-antibiotic feed additives, vaccinations, breed type, and feed type. The four most frequent outcomes were indices of immunity, non-specific morbidity, respiratory disease, and mortality. There were seven topic areas evaluated in clinical trials that may share enough commonality to support systemic reviews. There was a dearth of studies in which interventions were compared to antibiotic comparison groups.

Analytical validation of cardiac troponin I assays in horses.

Human cardiac troponin I (cTnI) assays have been used in equine medicine, often without prior analytical validation for equine use. In the absence of appropriate validation, the clinical significance of assay results is uncertain and can lead to misdiagnosis. We followed the American Society for Veterinary Clinical Pathology guidelines and investigated linearity, precision, limit of quantification (LoQ), and comparative recovery for 6 commercial cTnI assays developed for use in human medicine. Clinically acceptable linearity was observed in assays A-D, whereas assay E did not detect equine cTnI in any sample. Comparative recovery revealed 1-3-fold differences between assay results, and low analyte recoveries (2.2-3.4%) were observed in assay F. Precision was investigated in assays A and B, and found to be within acceptable limits. The LoQ was 1.53 ng/L for assay A, and 0.031 µg/L for assay B. Assays A and B performed within clinically acceptable limits and were deemed suitable for use in equine medicine. Assays C and D did not undergo full validation but had acceptable linearity, which demonstrates their potential for use in equine medicine. Assays E and F are unsuitable for use in horses given issues with detection of equine cTnI. The variability in results between assays indicates that reference intervals and cutoffs for diagnostic decision-making are assay specific and should be established prior to adoption by diagnostic laboratories.

Evaluation of contact activation of citrated equine whole blood during storage and effects of contact activation on results of recalcification-initiated thromboelastometry.

OBJECTIVE: To evaluate the degree of activation of the contact pathway in citrated equine whole blood over holding times ≤ 30 minutes and assess effects of contact activation on recalcification-initiated thromboelastometry. ANIMALS: 11 healthy adult mixed-breed horses. PROCEDURES: Blood was collected by atraumatic jugular venipuncture into prewarmed evacuated siliconized glass tubes containing citrate anticoagulant and held at 37°C for ≤ 30 minutes. Thromboelastometry was performed with an in vitro viscoelasticity (thromboelastometry) monitoring system. Factor XII and factor XI procoagulant activities were determined in contemporaneously collected platelet-poor plasma samples by assessing changes in turbidity for 1 hour at approximately 25°C, with clotting times calculated by fitting a line to the steepest segment of the absorbance curve and determining its intersection with baseline. Effect of holding time on thromboelastometry parameters and plasma enzyme activity was evaluated by repeated-measures ANOVA on ranks. Association of procoagulant activities with coagulation time was determined by Spearman rank-order correlation analysis. RESULTS: Thromboelastometry parameters (coagulation time, clot formation time, α angle, and maximum clot firmness) reflected significant increases in coagulability during the holding period. Factor XII and factor XI procoagulant activities were significantly increased at 30 minutes, compared with 2 or 10 minutes (indicating contact activation of samples), and had significant negative correlation with coagulation time. CONCLUSIONS AND CLINICAL RELEVANCE: Ex vivo activation of the contact system in equine whole blood was evident, suggesting that recalcification of blood in the absence of a trigger is not an acceptable method of assessing the hemostatic system in horses.