Effect of long term heparin administration in dogs

Because several literature reports suggested that heparin could sequester calcium from body tissues and one could reason that prolonged therapy might lead to osteoporosis, the effect of long term heparin administration was studied in dogs. Eight dogs (four males and four females) received subcutaneous injections of heparin at 250 units/kg bid, seven days a week. The female dogs were euthanatized after one year and the male dogs after two years. Pre and post-drug radiographs of the forelegs (radius, ulna, metacarpal bones) did not reveal any evidence of osteoporosis. As expected, the heparin did produce increased recalcification times and the development of occasional subcutaneous hematomas. But no effects were noted on various hematologic and blood chemistry parameters or on gross and microscopic tissue examinations.