2016 ACVIM Forum Research Abstract Program

To establish this, 25 horses from a pre-existing herd were used for this study. Of these, 13 were classified as EMS by the 2010 AVCIM consensus statement criteria, and 12 were non-EMS age matched controls. Within each group, 4 served as saline controls and the remaining horses served as vaccinates. A low-dose dexamethasone suppression test and TRH stimulation test were performed on all horses prior to the start of the study to insure no horses tested positive for pituitary pars intermedia dysfunction (PPID). Venous blood was drawn weekly for 6 consecutive weeks, with vaccination or saline administered intramuscularly on weeks 0 and 3. Horses were vaccinated with an inactivated influenza vaccine (Fluvac Innova-torÒ, Zoetis). Blood samples were used to determine humoral and cell mediated immune responses. Humoral immune responses against KY/97 were measured by hemagglutination assay for total Ig antibody responses and ELISA for IgGa, IgGb, and IgGt antibody isotype responses. Cell mediated immune measures were determined via PBMC isolation, EIV-stimulation, and subsequent flow cytometry and RT-PCR analysis for cytokine protein and gene expression, respectively. Humoral immune data were log transformed and analyzed using a repeated measures design with protected LSD, adjusting for age. All analyses were completed using PROC MIXED, SAS 9.4 (SAS Institute Inc., Cary, NC, USA). Results are expressed as least square means AE standard error of the mean. Data were considered statistically significant when P ≤ 0.05.