A Mare's Season in HorseBook: Heat Checks to a Foal on the Ground

By Brian Bickell, who builds HorseBook from a ranch in Oklahoma — usually from whatever the folks using it tell me is missing.

Ask anyone who's bred a mare where her season's records are, and the honest answer is usually "a few places." The cover date is on the kitchen calendar. The vet's ultrasound pictures are in a text thread. The check results are on an invoice in the truck. Come spring, somebody reconstructs the whole season from those pieces — and that somebody would rather not.

Here's how the season looks when it lives in one place instead.

It starts with her cycles

Log heat checks as the season opens — date, what you observed, what the vet found. The point isn't paperwork for its own sake; it's that when you and your vet are deciding timing, the pattern is in front of you instead of behind you.

The cover

When she's bred, log the breeding record: the date, the stallion, and the method — live cover or AI, cooled or frozen, embryo transfer or ICSI if that's the route your program takes. That one record is the anchor the rest of the season hangs off of.

The checks — with the pictures that matter

Pregnancy checks get their own records as the vet calls them: 14-day, heartbeat check, whatever schedule your vet runs. And you can pin the exam photos right to the check — the ultrasound picture goes with the record it belongs to, instead of aging out of your camera roll. Open it full-screen when the question comes up, and on the iPhone, pinch in close on what matters.

If she's on progesterone

If your vet has her on supplemental progesterone — Regumate, compounded altrenogest, whatever your program uses — log the course start and HorseBook puts the end date on your calendar. One less date to keep in your head between now and foaling.

The window, not a date

There's no such thing as a foaling due date; there's a window, and the mare picks her own night inside it. So the window is what goes on your calendar: opening at day 320, closing at day 350. The record's own timeline keeps the checkpoints — the safe date, the 340-day average, and the upper edge — for when you and your vet are planning the last stretch. Foal watch starts when it should, and the kit's by the stall in time. (Want just the math? The foaling date calculator is free, no account needed.)

And plenty of mares run their own schedule — breeders know their mare "always goes long" years before any chart says so. So once a mare has foaled for you, her record grows a gestation history card: her own earliest, average, and latest carry across the foalings you've logged. The textbook window still opens on the calendar; the history card tells you what she usually does with it. This one came straight from a breeder who knew her mare's real range off the top of her head and wanted her book to know it too.

A foal on the ground

When it's over, the foaling record closes out the season — and the foal starts a record of their own. The progeny book keeps a photo, titles, and earnings on every foal, so the next time someone asks what your mare's produced, the answer's right there.

On every plan

All of this — cycles, covers, checks and photos, the foaling window, progeny — is on every HorseBook plan, iPhone and web. A mare owner on the $4.99 Hobby plan gets the same breeding records as anyone else. (The Breeder plan is the stallion side: the stallion book and the booking-billing tools.)

And the paperwork the season generates — the breeding contract, the vet invoices, the registration application when the foal comes — you can photograph and let HorseBook read into records instead of typing it in.

If your mare's season currently lives on three calendars and a text thread, the 14-day free trial is a decent week to consolidate it — no card required. For the deeper record-keeping guide, see foaling records and mare tracking.