) Estroplan Injection is a prostaglandin analogue used to induce luteolysis in beef and dairy cattle. The luteolytic action of Estroplan injection can be utilized to manipulate the estrous cycle to better fit certain management practices; for treatment of unobserved or non-detected estrus and pyometra (chronic endometritis); to restore normal ovarian activity by causing regression of luteal cysts; for expulsion of a mummified fetus from the uterus; and to terminate pregnancies resulting from mis-matings. Estroplan Injection contains cloprostenol sodium, the equivalent to 250 mcg cloprostenol per ml. The recommended dosage is 2 ml per cow, given by IM injection only. Cloprostenol.