In this study, markers of endothelial activation were found to be increased in dogs with babesiosis at admission compared to healthy dog controls (TM, HMGB-1 and VCAM-1) and compared to day 6 of treatment (TM, ICAM-1, and HMGB-1), as well as between dogs with complicated and uncomplicated babesiosis (TM, HMGB1, ICAM-1, and VCAM-1). Here, VCAM1 is linked to babesiosis.