Assessment of oral vitamin K1 supplementation as part of preoperative medical therapy in dogs with congenital portosystemic shunts.

Dogs with congenital portosystemic shunts (cPSS) exhibit abnormalities in coagulation tests. Vitamin K1 has been recommended as part of the medical therapy prior to cPSS attenuation, although its usefulness is unknown. This work aimed to determine if oral vitamin K1 supplementation influences cPSS dogs' coagulation profile assessed by rotation elastometry (ROTEM). Seventeen cPSS dogs were prospectively included in a single-arm trial. Dogs were administered 1 mg/kg q12h of vitamin K1 orally for three days. ROTEM assays (INTEM, EXTEM, FIBTEM, APTEM) were measured twice in each dog namely before and after 3 days of vitamin K1 supplementation. Comparisons between both measurements were made using two-tailed Wilcoxon signed-rank testing. Vitamin K1 supplementation did not significantly change any of the ROTEM variables and three days of oral vitamin K1 supplementation does not have added value in the preoperative medical therapy of normocoagulable cPSS dogs.