ABORTIONS AND TWIN PREGNANCIES IN THOROUGHBREDS - RATE OF OCCURRENCE,TREATMENTS AND PREVENTION

Twin pregnancies recorded in German Thoroughbred mares were responsibl e for premature termination of 2.5% of 27 465 pregnancies between 1967 and 1992, and constituted 38.5% of all 1788 abortions (6.5% of all pr egnancies) recorded over the same time. Over time, the rate of twin pr egnancies dropped from 2.7% before 1984 to 1.7% thereafter (P<0.001). During the last 20 years several methods of treatment of early detecte d twin pregnancies were evaluated. Crushing of one embryo in 69 cases gave best results when conducted between Days 21 to 26 of pregnancy, r esulting in 80% single gestations continuing. Curtailing food intake d uring early twin pregnancies to enforce regression of the weaker conce ptus is difficult to manage. However, reducing feed intake for one cyc le prior to breeding in three mares with histories of frequent twin pr egnancies resulted in five single pregnancies in five attempts.