Heart disease is one of the most common problems seen in cats. In addition to the symptoms related to poor heart function, many cats with heart disease develop significant complications related to abnormal blood clotting. Unfortunately, few therapies are available that prevent the occurrence of blood clots and they remain a significant cause of death in cats with heart disease. The objective of this study is to develop an alternative therapy that will lead to effective inhibition of blood clot formation by the administration of essential fatty acids. Cats will be fed diets low in the fatty arachidonate, supplemented with other fatty acids. The effects of these fatty acids will be determined by evaluating platelet and lipoprotein fatty acid composition, platelet function and blood clotting inhibition.