Published online by Cambridge University Press: 09 March 2007
Pregnant mares are often removed from work during gestation. However, little is known about the effects of exercise on the pregnant mare and her foetus. In the present study, maternal and foetal heart rates were monitored by electrocardiography before and after exercise in four equine pregnancies (days 250–285). Exercise consisted of lungeing mares in 20 m circles for 5, 10 and 20 min. Following exercise, significant increases in maternal heart rate were detected (P<0.0001) but not in foetal heart rate (P = 0.4331). All mares gave birth to normal foals uneventfully. While these findings suggest that moderate exercise of the pregnant mare does not appear to be harmful to the equine foetus, data are insufficient to draw conclusions. A larger, more controlled study is necessary.