2018 ACVIM Forum Research Abstract Program: Seattle, Washington, June 14 - 15, 2018

The 19 included horses and ponies with SIRS had significantly more activated platelets and PLA in native PLRP than controls: CD62P 11.73 ± 3.74 % in SIRS and 1.74 ± 0.36% in controls (P = 0.0004); CD154 2.10 ± 0.91 % and 0.40 ± 0.08% respectively (P = 0.119); PLA 6.23 ± 1.18 % and 2.46 ± 0.32% respectively (P = 0.031). Six horses survived. There was a trend for more activation and PLA in nonsurviving horses. Furthermore a trend for reduced in vitro activation with collagen was detected in the non-survivors. This is the first study demonstrating increased platelet activation and platelet-leukocyte-aggregates with fluorescence flow cytometry in clinical cases of equine SIRS. Likewise platelet activation could be a prognostic factor in these patients. Antiplatelet therapy (e.g. clopidogrel) could be an additional therapeutic option in clinical cases of SIRS and other inflammatory diseases to prevent complications and improve outcome. In a cross-sectional study, serum samples from 454 Thoroughbred foals (aged 58-183 d) were analysed for anti-EqHV non-structural (NS)3-specific antibodies (Abs) with the luciferase immunoprecipitation system (LIPS) and for EqHV RNA by quantitative real-time polymerase chain reaction (qRT-PCR). Farms of origin (n=26) were situated in the Western Cape Province, South Africa. Descriptive analysis was performed to study associations between EqHV infection status, age and gender. Identified EqHV isolates were sequenced, with subsequent phylogenetic analysis of genomic portions located in the NS3-gene.