Vitamin K deficiency as a cause of oral bleeding in a dog with intestinal malabsorption due to lymphocytic-plasmacytic enteritis.

Background: Vitamin K, a member of the fat-soluble vitamin group, plays a key role in hemostasis by facilitating the activation of vitamin K-dependent clotting factors and contributing to the synthesis of various coagulation proteins. Consequently, its antagonization or deficiency secondary to reduced production or malabsorption impairs coagulation, leading to an increased risk of bleeding. Case Description: A 4-year-old, intact female German Shepherd was referred for a year-long history of anorexia, intermittent vomiting, and chronic diarrhea. She developed oral bleeding over the past 2 days. Diagnostic investigations revealed markedly prolonged prothrombin time (PT) and activated partial thromboplastin times (aPTT) with normal plasma fibrinogen levels. These findings, in conjunction with the normalization of PT and aPTT following vitamin K Conclusion: Vitamin K-responsive coagulopathy associated with malabsorption syndrome secondary to lymphocytic-plasmacytic enteritis was previously described in two cats, but this is the first report of its occurrence in a dog. Therefore, vitamin K supplementation should be considered in all animals with intestinal malabsorption.