Vitamin K Deficiency Vitamin K a fatsoluble vitamin

Vitamin K Deficiency � Vitamin K, a fat-soluble vitamin, is a group of napthoqunone compounds that have characteristic antihemorrhagic effects � Vitamin K extracted from plant material was named phylloquinone or vitamin K 1 � Vitamin K extracted from bacterial fermentation were named menaquinones or vitamin K 2 � A synthetic form named menadione (K 3)-simplest form of vitamin K, is is water soluble. Function: • The liver is the main repository of vitamin K. • Vitamin K is required for the hepatic post-synthetic transformation of several protein clotting factors � It is essential for the post-translational processing of the prothrombin group of coagulation factors (Factors II, VII, IX, and X). � Used as an antidote in poisoning by dicoumarol or warfarin.

�A role in bone metabolism, as well as in the renal reabsorption of Ca++. � Ruminant makes this through rumen microbial biosynthesis and absorbed in the small intestine � Horses generally receive sufficient vitamin K from pasture, hay, and intestinal bacteria to meet their needs. � Dogs receive both K 1 and K 2 in their diets, and cats derive their quinones from eating meat. Etiology: • Fat malabsorption associated with inadequate amounts of bile salts (eg, biliary obstruction) • Lymphangiectasia • Severe villous atrophy may result in vitamin deficiency and coagulopathy owing to the lack of production of the functional vitamin K−dependent Factors II, VII, IX, and X

� Vitamin K antagonist or by feeding sulfonamides (in monogastric species) � Mycotoxins � Moldy sweet clover hay/sweet clover disease-lead to hypoprothrombinemia , because of dicumarol combines with the proenzyme to prevent formation of the active enzyme required for the synthesis of prothrombin and also interferes with synthesis of factor VII and other coagulation factors. � Warfarin as a rodenticide � Insufficient vitamin K in the diet, � Lack of microbial synthesis within the gut � Inadequate intestinal absorption, or inability of the liver to use the available vitamin K.

Note: � Administration of estrogens increases absorption in both male and female animals � The lymphatic system is the major route of transport of absorbed phylloquinone from the intestine in mammals but by portal circulation in birds Clinical Signs: Ruminants: � Seen only in the presence of a metabolic antagonist, such as dicumarol from moldy sweet clover. ü The coumarin derivatives (dicumarol ) are not active in the fresh plant because they are bound to glycosides, but are active when sweet clover is improperly cured AND leads to sweet clover poisoning or hemorrhagic sweet clover disease ü Death from hemorrhage following a minor injury, or even from apparently spontaneous bleeding

� Accidental poisoning of animals with warfarin (a synthetic coumarin used as a rodent poison) ü Initial clinical signs may be stiffness and lameness from bleeding into muscles and articulations. ü Hematomas, epistaxis (nose bleed), or gastrointestinal bleeding ü Death may occur suddenly, with little preliminary evidence of disease, and is caused by spontaneous massive hemorrhage or bleeding after injury, surgery, or parturition DOGS AND CATS: � Accidental intake of dicumarol types of rat poison, such as warfarin and diphenadione (vitamin K antagonist), will result in a hemorrhagic condition in dogs � Clinical signs in dogs include paleness and evidence of slow but persistent bleeding from a number of sites,

Swine: �Increased prothrombin and blood-clotting time, internal hemorrhage, and anemia due to blood loss �Newborn pigs may be pale with loss of blood from the umbilical cord Diagnosis: �Determination of prothrombin time �Prolongation of the prothrombin time in the absence of liver disease indicates vitamin K deficiency �Measurement of the plasma concentration of one of the vitamin K-dependent clotting factors (Factor-II, VII, IX and X) �A routinely measure circulating phylloquinone as a method of evaluating vitamin K status. <0. 5 ng/ml have been associated with impaired clotting functions

Treatment: � Vit. K 1 @1 - 2 mg/kg administered intramuscularly /SC (especially in Dicumarol poisoning) � Blood transfusion@10 ml/Kg BW Note: � Vitamin K 3 should not be used, especially in horses, because it is associated with renal damage � In horses, the recommended dose (Vitamin K 3 ) is 0. 5 to 2. 5 mg/kg BW IM