2017 ACVIM Forum Research Abstract Program

Six healthy laboratory beagles were experimentally infected with E. canis via needle inoculation. Four dogs were inoculated from one naturally infected dog and two dogs were inoculated from a second naturally infected dog. Four dogs became positive for E. canis via serology and PCR but the remaining two dogs never became positive despite repeated testing. As a result, the four dogs were designated as positive and the two dogs were designated as negative. Platelet indices; platelet count, mean platelet volume (MPV), plateletcrit (PCT), platelet volume distribution width (PDW), mean platelet mass (MPM), mean platelet component concentration (MPC) and platelet component distribution width (PCDW) were measured. For platelet aggregometry, the area under the curve (AUC) was recorded using a saline control (AUC saline ) and for each agonist (adenosine diphosphate (ADP) [AUC ADP ] and arachidonic acid (AA) [AUC AA ]). Percent IgG was assessed by direct flow cytometry. Tissue factor (TF)-activated TEG and TF-activated TEG + tissue plasminogen (tPA) were performed. TEG variables (reaction time (R), clotting time (K), rate of clot formation (a), and maximum amplitude (MA), LY30 (percent clot lysis 30 minutes after MA), CL30 (clot lysis 30 minutes after MA), LY60 (percent clot lysis 60 minutes after the MA), and CL60 (clot lysis 60 minutes after MA)) were recorded in addition to the velocity curve variables: maximal rate of thrombus generation (MRTG), time to maximum rate of thrombus generation (TMRTG), total thrombus generated (TG), maximum rate of lysis (MRL), time to maximal rate of lysis (TMRL), and total lysis (L). Testing was performed in both the positive and negative dogs prior to inoculation and then on weeks 1, 2, 3, 4, and 5. Due to clinical signs (weight loss, hyporexia, lethargy, fever), the positive dogs were administered doxycycline at 10 mg/kg, PO, daily between week 3 and week 4. For each variable, a repeated measures analysis (2-way ANOVA) with post-hoc analysis was performed comparing the positive and negative dogs. For all analysis, P < 0.05 was considered significant.