Mares carry their foals for 340 days on average, but gestation can range from 320 to 365 days or even longer. So, how’s a person to know when delivery is imminent?
The external changes a mare undergoes provide important clues. For example, her udder typically starts to swell with milk and antibody-rich colostrum 2 to 6 weeks before her due date. Within a week before foaling, the mare’s teats engorge, and a bead of wax forms at their tips 1 to 2 days before delivery.
The mare’s muscles start to relax and soften as well — along her belly and on either side of the tailhead. Finally, a few days before foaling, the tissue alongside the opening to the mare’s birth canal begins to swell and the opening elongates.
Following this timeline of clues can help you prepare for the big event.