Foaling Records and Mare Tracking: Breeding to Birth (2026 Guide)

By Brian Bickell, who raises paint and quarter horses at Bickell Ranches in Stillwater, Oklahoma. His first foaling season taught him that the records you keep during breeding are the ones that save you during foaling.

Every breeder has a story about the foaling they didn't document well enough. The mare who always foaled at day 335 who went to day 348, and nobody noticed the pattern was off until they were panic-calling the vet. The foal with partial failure of passive transfer that could have been caught with a routine IgG test. The breeding season where three mares didn't conceive, and nobody had recorded the post-breeding fluid checks to figure out why.

Foaling records aren't busywork. They're the data that makes your next breeding season better than this one.

Educational, not veterinary advice or an emergency protocol. Foaling is a medical event. Build your plan with your vet ahead of the season, and call them when anything looks off — this guide exists to help you recognize and record what's happening, not to replace the phone call.

In This Guide

• Pre-Breeding Records
• Heat Cycle Tracking
• Breeding Records
• Pregnancy Monitoring
• Foaling Records
• Neonatal Records (First 30 Days)
• What Experienced Breeders Track That Novices Miss

Pre-Breeding Records

Before breeding, establish the mare's reproductive baseline:

Reproductive History

For every previous pregnancy, document: gestation length, foaling ease (scored 1–5, from unassisted to dystocia requiring vet intervention), complications (retained placenta, uterine tears, post-foaling laminitis), and foal outcome.

Pre-Breeding Veterinary Exam

Your vet should perform:

• Uterine culture and cytology — rules out endometritis, the leading cause of early embryonic loss
• Uterine biopsy (for mares over 15 or with poor breeding history) — graded on the Kenney-Doig scale. Grade I is normal. Grade III means severe fibrosis with less than 10% chance of carrying to term. This determines whether breeding is realistic.
• Ovarian ultrasound — assess follicular activity, check for abnormalities (granulosa cell tumors, anovulatory follicles)
• Caslick's vulvoplasty documentation if performed — record date, degree of closure, and planned opening date before foaling (typically day 320+)

Heat Cycle Tracking

Teasing Scores

Record daily teasing scores during breeding season using a consistent scale:

Score	Behavior
0	Hostile — ears pinned, kicks
1	Indifferent — no interest
2	Mild interest — approaches, no posturing
3	Moderate — winking, urination, intermittent tail raising
4	Strong estrus — consistent winking, squatting
5	Peak standing heat — fully receptive, leaning into teaser

The normal cycle is 21 days: 5–7 days of estrus followed by 14–16 days of diestrus. A mare progressing from 0→3→5 over several days is approaching ovulation.

Transitional Heat

In early spring (February–April), mares produce irregular, prolonged estrus — sometimes 20+ days, as they emerge from winter anestrus. Multiple follicles grow and regress without ovulating. Don't breed during transitional heat. Wait for the first true ovulation of the season.

Lights-under-management: 16 hours of light (natural + artificial, minimum 200 lux at eye level) starting December 1 advances first ovulation by 6–8 weeks. Record the start date and confirm cyclicity by ultrasound in early February.

Breeding Records

For each breeding event:

• Date and time of insemination or cover
• Method: live cover, AI fresh, AI cooled/transported, AI frozen
• Stallion identification (registered name, registration number)
• Semen quality at insemination (for AI): progressive motility, concentration, total motile sperm count. Minimum targets: 500 million progressively motile for cooled; 200–300 million for frozen.
• Pre-ovulation follicle size
• Ovulation induction if used (hCG or deslorelin, with date and time)
• Ovulation confirmation via ultrasound
• Post-breeding fluid check at 6–12 hours and 24 hours — fluid greater than 2cm requires treatment (oxytocin, lavage). This single check prevents more early pregnancy losses than almost anything else you can do.

For the full breakdown of breeding documentation — including stallion records, semen evaluations, contracts, and registry-specific rules — see our breeding documentation guide.

Pregnancy Monitoring

The Check Schedule

Timing	What to Look For
Day 14–16	Confirm embryonic vesicle. Check for twins — unmanaged twins have ~90% chance of losing both. Reduce by manual crush at this stage.
Day 25–30	Heartbeat visible (~120 bpm). Embryonic loss rate is 5–15% between days 15–45.
Day 35–40	Endometrial cups forming. After day 36–38, loss means the mare won't cycle back that season.
Day 45	Confirm continued development. Most early losses have occurred by now.
Day 60–70	Optional fetal sexing — 95%+ accuracy at 60–65 days by experienced practitioner.
Day 90–120	Mid-gestation check. Fetal viability, placental health.
Day 300+	Pre-foaling monitoring.

Gestation Tracking

Average gestation is 340 days (range 320–370). But the population average matters less than your individual mare's pattern.

Track gestation length per mare. Mares are remarkably consistent across pregnancies — typically within 5–7 days of their personal average. A mare who always foals at day 335 going to day 350 is abnormal for her, even if 350 is within the normal population range. This data is only available if you recorded previous gestations.

Other trends: colt foals tend to gestate 2–3 days longer than fillies. Maiden mares often run longer.

Pregnant Mare Vaccinations

Don't neglect the vaccination schedule during pregnancy: killed EHV vaccine (Pneumabort-K or equivalent) at months 3, 5, 7, and 9 of gestation. Core vaccine boosters 4–6 weeks before foaling for maximum colostral antibody transfer to the foal. See our vaccination guide for the full protocol.

Pre-Foaling Signs to Record

• Udder development timeline — when it started filling, how it progressed
• Waxing of teats — waxy beads on teat ends, typically 24–48 hours before foaling
• Milk calcium levels — testing with a commercial kit (>200 ppm calcium is strongly predictive of foaling within 24–48 hours)
• Relaxation of the vulva and pelvic ligaments

Tip: HorseBook tracks the full cycle — breeding dates, pregnancy milestones, foaling details, and neonatal records — all under one mare's profile. When your vet asks "when did she wax last time?" you'll have the answer.

Foaling Records

The Three Stages of Labor

Stage 1 (1–4 hours): Restlessness, pawing, flank-watching, sweating, frequent posture changes. Record onset time. Some mares show minimal Stage 1 signs — track patterns across foalings, because individual mares are consistent year to year.

Stage 2 (15–30 minutes): Active delivery. Record:

• Time of membrane rupture (water breaking)
• First appearance of feet (should be soles-down, one foot slightly ahead of the other, nose resting on forelegs)
• Total time from water breaking to delivery

The 30-minute rule: If the foal isn't delivered within 30 minutes of water breaking, call the veterinarian immediately. Dystocia in horses is a true emergency. Every minute counts.

Red bag delivery (premature placental separation — you see red/maroon membrane instead of the normal white amnion) is a true emergency. Call your vet immediately. Standard emergency guidance is to open the membrane so the foal can breathe, but this is exactly the kind of thing to walk through with your vet before foaling season so you know the plan for your operation. Document it either way — it signals placental problems that affect future breeding decisions.

Stage 3 (within 3 hours): Placenta passage. Record the time. A retained placenta beyond 3 hours is a veterinary emergency due to the risk of metritis and founder. The standard non-clinical practices are to avoid pulling on the placenta and to tie it above the hocks so the mare doesn't step on it while you wait for your vet.

Foal Assessment at Birth

Record:

• Sex, color, markings — with photos from all four sides and face (registries require detailed marking descriptions)
• Birth weight if available (average 100–120 lbs for light breeds)
• Time to sternal recumbency — normally within 5 minutes
• Time to stand — normally within 1 hour
• Time to nurse — normally within 2 hours. This is critical — colostrum absorption decreases rapidly after 6–8 hours and is negligible by 24 hours.
• Meconium passage — first dark, firm stool, normally within 4 hours. Colt foals are more prone to meconium impaction.

Colostrum and IgG

Colostrum quality: Measure with a Brix refractometer before the foal nurses. Greater than 23% Brix indicates good quality. Bank excess high-quality colostrum frozen in flat ziplock bags — it's good for 1–2 years at -20°C and could save another foal's life.

IgG test at 12–24 hours: Widely considered the single most important neonatal test. It measures passive transfer of maternal antibodies from colostrum. Reference ranges commonly used:

• Above 800 mg/dL — adequate transfer
• 400–800 mg/dL — partial failure
• Below 400 mg/dL — failure of passive transfer

Record the exact value, not just "pass" or "fail." Your vet interprets the result in context and decides whether plasma or other intervention is warranted. The test is inexpensive and fast — most breeders consider it a standard part of the first day.

Placenta Examination

Lay the placenta out in an "F" shape (the pregnant horn is longer). Check for completeness. Any missing pieces mean retained tissue and require veterinary attention.

Record:

• Weight — normally 10–14 lbs (4.5–6.5 kg) for light breeds. Weight over 10% of foal's birth weight suggests placentitis.
• Color — should be red/maroon on the uterine side, blue-gray on the foal side
• Thickness — abnormal thickening indicates placentitis
• Completeness — both horns intact, cervical star visible

Umbilical Care

Dip the stump in 0.5% chlorhexidine (not strong iodine, which causes chemical burns) 2–3 times in the first 24 hours. Record stump condition daily until dry.

Neonatal Records (First 30 Days)

Track daily:

• Nursing frequency — foals nurse 5–7 times per hour in short bouts
• Urination — should see within 6–10 hours of birth
• Defecation — transition from meconium to milk stool within 24 hours
• "Foal heat scours" around day 7–10 when the mare cycles — usually self-limiting, but monitor hydration

Weight gain: Foals should gain 1–3 lbs daily. Failure to gain is an early warning.

First farrier visit: 2–4 weeks for evaluation. Angular limb deviations (toed-in, toed-out, carpal/fetlock valgus) are correctable if caught early — before 2–3 months for fetlock deviations, before 4–6 months for carpal. Missing the window means surgical options or permanent conformation issues.

Foal vaccinations: Begin the core vaccine series at 4–6 months if the mare was properly vaccinated (3–4 months if her vaccination history is unknown). See our vaccination guide for the complete foal schedule.

Registration: Most breed registries require foal reporting within 30–90 days. See our breed registration guide for deadlines and fees by registry. DNA/parentage verification (hair sample) is required by all major registries. Record the submission date and registration number when returned.

What Experienced Breeders Track That Novices Miss

After a few seasons, you learn that the most valuable records are the ones nobody told you to keep:

• Gestation length per mare — your best predictor of when she'll foal next year
• Foaling presentation — mares who've had dystocia are at higher risk in subsequent foalings
• Colostrum Brix readings — a mare who consistently produces low-quality colostrum needs a banked colostrum plan for next time
• Breeding soundness trends — track uterine fluid clearance time, cycles to conception, and early pregnancy loss rate across seasons. Deteriorating trends signal declining fertility before it becomes clinically obvious.
• Mare behavior patterns — individual mares are consistent across years. The mare who always foals lying down, always in the early morning, always waxes exactly 24 hours prior — these patterns are predictive and worth recording.

This is data you can only build over time, and it's only useful if you can find it next season. A notebook from three years ago in a tack trunk is not a system. HorseBook keeps it all linked to each mare's profile — searchable, sortable, and available when you're standing in the foaling stall at 2 AM wondering if day 348 is normal for this particular mare.

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Brian Bickell is the founder of HorseBook and raises paint and quarter horses at Bickell Ranches in Stillwater, Oklahoma.