A mare is pregnant for roughly 11 months — about 340 days on average, though anywhere from 320 to 370 days is considered normal. Foals born a little early or late within that window are usually perfectly healthy. Gestation length varies by individual mare, breed, and even the time of year the foal is due.
The average equine gestation is 340 days, or about 11 months and one week. A range of 320 to 362 days is normal and healthy. Mares foaling in early spring, when days are shorter, sometimes carry slightly longer than those foaling in summer. Because the normal window is wide, a due date is always an estimate rather than a fixed appointment.
In the final weeks, watch for udder development (bagging up), relaxation of the muscles around the tailhead, and waxing — small beads of colostrum at the teats, often 24 to 48 hours before birth. Most mares foal at night, quickly and without help. Have your equine veterinarian on call and know the signs that labor is not progressing normally.
If you are breeding, choose your breeding service carefully and confirm pregnancy with your vet through ultrasound at the usual checkpoints. Good preventive care throughout gestation — including a sensible vaccine and deworming schedule adjusted for pregnancy — sets up both mare and foal for a healthy start.
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Find a Breeding ServiceAbout 340 days on average, roughly 11 months. Anywhere from 320 to 370 days is considered normal.
Occasionally. Some mares carry to 370 days or slightly beyond and still deliver a healthy foal. Much past that, your vet should evaluate the mare.
Look for udder development, softening around the tailhead, and waxing at the teats, which often appears 24 to 48 hours before birth.
On average colts are carried slightly longer than fillies, but the difference is small and varies by mare.
Most mares foal at night or in the early morning hours, typically quickly and without assistance.
