Since the mare's age and the number of foals she's carrying also influence her due date, a mare may foal early or late regardless of the time of year. It pays to start keeping an eye on your mare at least 10 days before she is due to foal. The easiest way to calculate the due date is to subtract 25 days from the breeding date. If, for example, the mare is bred in February 27, she will be due to foal approximately on February 2 of the following year. Abomen develops a point at the lowest portion.
Teats become shinky and tight.
Nipples wax up about 24 to 48 hours before the mare foals. Milk may drip from the nipples when the mare walks. Vulva enlarges and relaxes. Tail and hip muscles drop, making the tailhead stick out. Its time to keep an eye on her.