Disease investigations for equine infectious anemia in Canada (2009-2012) - Retrospective evaluation and risk factor analysis.

This retrospective study describes the detection of equine infectious anemia (EIA) during Canadian Food Inspection Agency (CFIA) disease investigations in Canada, examines aspects of importance for disease control, and evaluates potential animal-level risk factors for EIA in high-risk horses. Based on review of all EIA-positive samples and all samples collected during disease investigations (N = 4553) over a 4-year period (2009 to 2012), 409 EIA cases were detected. Horse owners with EIA cases owned between 1 and 60 affected animals, and 49 horses seroconverted during a disease investigation period. Twenty-nine percent of cases (n = 68) for which this information was available had, or possibly had, clinical signs of EIA. Using a mixed effects logistic regression model, horses in older age groups were at greater odds of having a positive EIA status. The study emphasizes the importance of disease investigation activities when EIA is detected and identifies age as an animal-level risk factor in high-risk horses.

Enquêtes médicales pour l'anémie infectieuse équine au Canada (2009­2012) ­ Évaluation rétrospective et analyse des facteurs de risques. Cette étude rétrospective décrit la détection de l'anémie infectieuse équine (EIA) durant les enquêtes médicales de l'Agence canadienne d'inspection des aliments (CFIA) au Canada, examine les aspects importants pour la maitrise de la maladie, et évalue les facteurs de risque potentiels au niveau des animaux pour l'EIA chez les chevaux à risque élevé. Sur la base d'une revue de tous les échantillons positifs pour l'EIA et tous les échantillons prélevés durant les enquêtes (N = 4553) pendant une période de 4 ans (2009­2012), 409 cas d'EIA furent détectés. Les propriétaires de chevaux avec EIA possédaient entre 1 et 60 animaux affectés, et 49 chevaux ont séro-converti durant une période d'enquête. Vingt-neuf pourcents des cas (n = 68) pour lesquels l'information était disponible avaient, ou avaient possiblement eu, des signes cliniques d'EIA. Utilisant un modèle de régression logistique à effets mixtes, les chevaux des groupes d'animaux plus âgés étaient à plus grand risque d'avoir un statut positif pour l'EIA. Cette étude fait ressortir l'importance des activités d'enquêtes médicales lorsque l'EIA est détectée et identifie l'âge comme étant un facteur de risque au niveau de l'animal chez les chevaux à risque élevé.(Traduit par Dr Serge Messier).

A retrospective study of owner-requested testing as surveillance for equine infectious anemia in Canada (2009-2012).

This retrospective study was undertaken to estimate i) the surveillance coverage for equine infectious anemia (EIA) based on owner-requested testing, and ii) the incidence of case detection from this surveillance activity to inform a review of Canada's national disease control strategy. Based on sample submissions by accredited veterinarians to laboratories CFIA-approved for EIA testing between 2009 and 2012, the estimated national surveillance coverage was 14% for all years, and 72 cases of EIA were detected. The annual national incidence of EIA detection ranged from 0.03 to 0.08 cases/1000 horses. On average, a greater proportion of the horse population was tested in eastern Canada (32%) than in western Canada (6%, P < 0.0001). The cumulative incidence of EIA detection was higher in western Canada (0.25 cases/1000 horses) than in eastern Canada (0.02 cases/1000 horses, P < 0.0001). This study identified regional differences in owner-requested EIA testing and case detection resulting from this testing activity.

Étude rétrospective des tests demandés par les propriétaires comme surveillance pour l'anémie infectieuse équine au Canada (2009­2012). Cette étude rétrospective a été entreprise afin d'estimer i) la couverture de surveillance pour l'anémie infectieuse équine (AIE) basée sur les tests demandés par les propriétaires et ii) l'incidence de détection des cas à partir de cette activité de surveillance pour documenter un examen de la stratégie nationale de contrôle des maladies du Canada. L'estimation de la couverture nationale de surveillance, basée sur les soumissions d'échantillons par les vétérinaires autorisés aux laboratoires approuvés par l'ACIA pour l'AIE entre 2009 et 2012, était de 14 % pour toutes les années et 72 cas d'AIE ont été détectés. L'incidence nationale annuelle de la détection de l'AIE variait de 0,03 à 0,08 cas/1000 chevaux. En moyenne, une proportion supérieure de la population équine de l'Est du Canada (32 %) subissait des tests par rapport à l'Ouest canadien (6 %, P < 0,0001). L'incidence cumulative de la détection de l'AIE était supérieure dans l'Ouest canadien (0,25 cas/1000 chevaux) par rapport à l'Est du Canada (0,02 cas/1000 chevaux, P < 0,0001). Cette étude a identifié des différences régionales pour les tests de l'AIE demandés par les propriétaires et la détection des cas découlant de cette activité d'épreuve diagnostique.(Traduit par Isabelle Vallières).

An investigation into human pandemic influenza virus (H1N1) 2009 on an Alberta swine farm.

On May 2, 2009 the Canadian Food Inspection Agency notified the World Organization for Animal Health that an emerging novel influenza A virus (pandemic H1N1 2009) had been confirmed on a swine farm in Alberta. Over a 4-week period pigs in this farrow-to-finish operation were clinically affected by respiratory disease consistent with an influenza A virus infection and the presence of active viral infection was confirmed in all production areas by real-time polymerase chain reaction (RT-PCR). Despite clinical recovery of animals, there was reluctance by purchasers to receive animals from this operation due to concerns about the effect on both domestic and international markets. The owner decided to depopulate the entire herd due to impending welfare issues associated with overcrowding and economic concerns resulting from the inability to market these animals. Carcasses were rendered or composted and did not enter the human food or animal feed chain. The source of virus in this herd was determined to be an infected human. Zoonotic transmission to 2 individuals responding to the outbreak was suspected and recommendations to prevent occupational exposure are discussed.

Androgen insensitivity syndrome in a thoroughbred mare (64, XY--testicular feminization).

A Thoroughbred mare was presented for stallion-like behavior. Reproductive and ultrasonographic evaluation, testosterone assays, and karyotyping confirmed a diagnosis of androgen insensitivity syndrome (64, XY--testicular feminization). Surgery to remove abdominal testicles was successful in alleviating the behavioral abnormality. This condition is discussed with reference to the current literature.

Cardiopulmonary effects associated with head-down position in halothane-anesthetized ponies with or without capnoperitoneum.

OBJECTIVE: To compare the cardiopulmonary effects of the head-down position, with or without capnoperitoneum, in halothane-anesthetized horses. STUDY DESIGN: Prospective randomized study. ANIMALS: Five ponies (four mares, one stallion; bodyweight 302 ± 38.4 kg [mean ± SD]) were used. METHODS: The ponies were anesthetized with xylazine, guiafenesin, ketamine, and maintained with halothane/oxygen and lungs were ventilated to 40 ± 2 mm Hg (5.3 ± 0.3 kPa) end-tidal CO2 tension. After baseline cardiopulmonary measurements, ponies were kept in horizontal position for 30 minutes, then tilted head-down 30° to the horizontal position for 60 minutes, and then returned to a horizontal position for final measurements. Capnoperitoneum (intra-abdominal pressure: 12 mm Hg [1.6 kPa]) was introduced after baseline cardiopulmonary measurements, until 5 minutes before the final measurements (treatment INS). Ponies in the control treatment (CON) did not receive capnoperitoneum. Cardiopulmonary data were collected every 10 minutes following the baseline measurements until recovery. RESULTS: In the head-down position, in both treatments, significant decreases were observed in PaO2, and significant increases were observed in PaCO2, right atrial blood pressure, arterial to end-tidal CO2 gradient, calculated Vd/Vt and Q˙s/Q˙t ratios. During the head-down position, in CON there was decreased cardiac index, and in INS, there were decreases in arterial plasma pH and increases in mean systemic arterial and airway pressures. Treatment INS developed ventilation-perfusion mismatch earlier in the study, and had longer recovery times compared to CON. CONCLUSION: Cardiac index and systemic blood pressure appeared to be preserved in INS during the head-down position, but ventilation-perfusion mismatch appeared earlier with head-down position and capnoperitoneum. CLINICAL RELEVANCE: Healthy ponies tolerate capnoperitoneum at 12 mm Hg (1.6 kPa) intra-abdominal pressure when tilted head down 30° to the horizontal position.