Coagulation abnormalities can develop as a result of decreased synthesis or activation of coagulation factors produced in the liver (ie, Factors V, VII, IX, X, XI, XII, fibrinogen, prothrombin, antithrombin III, protein C, plasminogen, α2-macroglobulin, and α1-antitrypsin). Decreased enteric absorption of fat-soluble vitamins can lead to vitamin K-responsive bleeding in animals with EHBDO or bile duct immuno-injury (feline sclerosing cholangitis), or cats with HL. Cats appear predisposed to vitamin K-responsive coagulopathies. Conventional coagulation assessments usually do not discover coagulopathies unsuspected after physical examination, analysis of urine or feces, or mucosal bleeding time test. Dogs with congenital or acquired portosystemic shunting usually develop low protein C activity (<70%) that seemingly reflects the severity of portosystemic shunting.
Last full review/revision March 2012 by Sharon A. Center, DVM, DACVIM