Vitamin K-dependent multifactor coagulopathy in Devon Rex cats.

A coagulopathy attributable to a deficiency of vitamin K-dependent clotting factors (II, VII, IX, and X) was diagnosed in 3 Devon Rex cats. There was no evidence for exposure to vitamin-antagonist-related rodenticides. The cats did not have evidence of hepatic disease, gastrointestinal disease, or fat malassimilation. Oral treatment with vitamin K1 resulted in normalization of clotting factor concentrations. However, when treatment was discontinued in 2 cats, prothrombin and activated partial thromboplastin values became prolonged again, although the cats did not have clinical signs of a bleeding disorder.