Figures generated from ultrasound examinations undertaken on mares over 42 days of gestation by veterinarians specializing in equine reproductive practice in central Kentucky provide the following information.

Of 3089 mares examined between April 30 and May 17, 2783 (90%) remain pregnant. The normal rate of loss over this time period would range from 1-2%. The figures are derived from members of two equine practices in Lexington serving a large number of horse farms in the area