Extensive studies have been conducted with monensin in target animals and laboratory animals to determine monensin concentrations in tissues, route of elimination, metabolism and pharmacokinetics of monensin. These studies indicate that monensin administered orally is absorbed, extensively metabolized, excreted in the bile and eliminated in the feces by the several species examined. Monensin did not accumulate in the tissues of orally dosed animals. When fed to cattle and chickens according to recommended practices, monensin was not detected (less than .05 ppm) in edible tissues. Environmental studies indicate that monensin is biodegradable in manure and soil.