Comparison of the pharmacokinetics and pharmacodynamics of apixaban and rivaroxaban in dogs.

Background: Comparative pharmacokinetics and pharmacodynamics (PK/PD) of apixaban and rivaroxaban have not been studied in dogs and the propensity of these drugs to cause hypercoagulability after discontinuation is unknown.

Hypothesis: Compare the PK/PD of clinical dosing regimens of PO apixaban and rivaroxaban administered repeatedly to healthy dogs and assess the effect of abrupt drug discontinuation on coagulation.

Animals: Six University-owned, purpose-bred, middle-aged, mixed-breed dogs (4 male, 2 female).