Abstract
Two cats with intestinal malabsorption developed a hemorrhagic diathesis. Although unsubstantiated, the probable cause of bleeding was a chronic malabsorption of fat and the fat-soluble vitamin K. When treated with vitamin K1 per os, one cat's clotting times were only partially corrected. Since vitamin K1 is actively absorbed in the proximal small intestine, the incomplete response of this case to orally administered vitamin K1 was predictable. The infrequent occurrence of bleeding in animals with malabsorption is, in part, attributable to the ileal and colonic absorption of bacterially derived vitamin K2. For this reason, nonspecific use of antibiotics in these animals is contraindicated. Since long-chain, polyunsaturated fats impair vitamin K absorption, dietary fat given to animals with malabsorption should be restricted to medium- and short-chain, saturated fats. Vitamin K should be administered subcutaneously to these animals if prolonged clotting times or active bleeding is present, and routinely prior to surgery. Oral supplementation with vitamin K3, which is absorbed in the colon and less lipid soluble than vitamin K1, should be given to animals with malabsorption that are maintained as outpatients. Adequate dosage levels of vitamin K3, however, are yet to be established for the cat, and dose-dependent hemolytic anemia is a probable toxic manifestation.