Mare Gestation Calculator

A mare's pregnancy averages roughly 340 days, but normal gestation varies substantially. This calculator adds a planning interval to the recorded breeding date and presents an estimated foaling date with a two-week window on either side. Standard horses use 340 days, the pony profile uses 330 days, and the draft profile uses 345 days. These profiles are convenient estimates rather than breed-specific biological rules, and individual mares may foal outside the displayed window. Accurate breeding records are essential when mares were covered or inseminated on more than one date. A veterinarian may use ultrasound to identify ovulation, confirm pregnancy, evaluate twins, and monitor fetal development. The early check shown at day 16 is a common scheduling reference for initial ultrasound, while day 28 is a useful reference for a heartbeat follow-up. Actual examination timing should follow the veterinarian's protocol and the mare's reproductive history. Nutrition, vaccination, deworming, dental care, exercise, transport, and medication decisions should be planned with an equine veterinarian. Body condition should be monitored through pregnancy without abrupt dietary changes. During late gestation, prepare a clean and safe foaling area, review emergency procedures, and arrange suitable observation. Maiden mares and animals with previous reproductive complications may need a more individualized monitoring plan. Signs that foaling may be approaching include udder development, waxing, relaxation around the tail head, changes in behavior, and alterations in milk electrolytes, but no single sign predicts the exact hour. Normal equine labor can progress rapidly. Owners and attendants should know when delayed progression, abnormal presentation, excessive bleeding, retained placenta, weakness, or other concerns require urgent veterinary attention. This calculator supports scheduling only. It cannot confirm pregnancy, diagnose complications, predict a precise foaling time, or establish that a mare or foal is healthy. Gestation length is influenced by season, fetal sex, mare age, breed, individual history, and other factors. Keep the calculated dates with veterinary findings and the mare's prior foaling records, then update preparations as clinical information becomes available.