How to Wean a Foal: Why New Research Says Go Slow, Not Abrupt

How to wean a foal: the short answer

To wean a foal with the least stress, do it gradually and socially: let mare and foal get used to being apart over days or weeks, keep them able to see, hear and smell each other at first, and wean alongside familiar foals or a calm older horse. Never shut a foal alone in a stall to cry it out.

That advice just got fresh backing. On October 10, 2026, Horse & Hound reported on a University of Nottingham study arguing there's an urgent need to change how and when foals are weaned, right as fall weaning season gets going on many farms.

What the new Nottingham study found

The paper, Stable Beginnings: A call to transform methods of weaning horses, was published in 2026 in the Journal of Equine Veterinary Science (article 106148). Its authors are Joanne Dwyer, Sarah Freeman, Brad Hill and Amanda Roshier of Nottingham's School of Veterinary Medicine and Science.

The researchers showed welfare professionals, mostly from UK equine charities, videos of different weaning methods plus a chart of behavioral welfare signs. They then recorded the group's discussions and analyzed the themes that came up.

The key results:

• Everyone agreed that abrupt, isolating weaning compromised the short-term welfare of both mare and foal.
• They also agreed it could lead to long-term psychological problems.
• The authors call for a shift to gradual, social, lower-stress weaning, driven by education and by buyers who value horses with good early-life experiences.
• Barriers they named include tradition and lack of awareness in the horse world.

How much weight to give it

This is a small qualitative study with five participants. It captures expert opinion; it didn't measure stress hormones or follow foals for years.

Still, it fits earlier hard data. A 2018 French study in Psychoneuroendocrinology compared 16 mare-foal pairs weaned suddenly with 18 pairs that first got used to separation across a fence line for a month. The progressively weaned foals neighed and trotted less and had lower cortisol on weaning day, and they were more curious and less fearful for at least three months afterward.

Abrupt vs gradual weaning: the main methods

Here's how the common approaches compare.

Abrupt weaning

Abrupt weaning means mare and foal go from together to completely apart in one step, with no sight, sound or smell of each other. It's quick and simple, and it's still a long-standing tradition on many farms.

World Horse Welfare calls sudden separation extremely stressful and doesn't recommend it. If a farm uses it anyway, Oklahoma State University Extension advises at least not isolating the foal entirely. A single foal buddy isn't a guaranteed fix, though: the 1990 study Oklahoma State cites found more signs of stress in foals weaned in pairs than in foals weaned singly, possibly from aggression by a dominant partner. Oklahoma State notes that foals kept with calm, unrelated adults show less stress.

Fence-line weaning

In fence-line weaning, mare and foal go into side-by-side paddocks or stalls that share a safe fence. They can see, hear and smell each other, but the foal can't nurse.

After several days to about a week, the mare moves out of sight. Oklahoma State notes the foal keeps some of the security of having its dam nearby during those first days.

The fence matters most. Use solid rails or tight horse mesh, never barbed wire or loose strands, and make sure there are no gaps a hoof or head could get stuck in.

Gradual group weaning with a nanny horse

With several foals, the gentlest option is often to keep the foals together in the paddock they already know and take the mares away one or two at a time. Oklahoma State says foals that stay in familiar surroundings with peers of similar age and size show less stress.

Adding a calm, unrelated adult helps even more. Research cited by Oklahoma State found foals kept with tolerant older horses had lower cortisol, called less and were less aggressive than foals weaned with only other youngsters.

World Horse Welfare describes a stepwise version: start with mares and foals in adjacent fields, increase time and distance a little each day, then move from a shared fence to across a track, then to a field beyond a hedge.

A note on short separations

Not every study agrees on the details. Oklahoma State cautions that brief out-of-contact separations followed by full reunions didn't help in some research and may even sensitize foals to separation.

The common thread across sources: keep contact at first, then add distance steadily. Don't bounce a foal back and forth.

Why weaning a foal alone is discouraged

Horses are herd animals, and a young foal's sense of safety comes from its mother and herd. Removing both at once stacks two big stressors.

According to World Horse Welfare, stressful weaning can raise a foal's risk of injury, illness and weight loss. It has also been linked to stereotypic behaviors such as crib-biting, wind-sucking, box-walking and weaving.

Oklahoma State adds that foals weaned in pasture groups developed fewer stereotypies over time than foals weaned in stalls or barns, singly or in pairs. A frantic foal may also run fences, and Oklahoma State warns that nervous foals are easily hurt on protrusions such as feed troughs or by catching a leg in any gap wider than a hoof.

What about adult horses that panic when left alone? The experts in the Nottingham study believe abrupt, isolating weaning may cause psychological problems that last into adulthood. That link is plausible but not proven, so treat it as a reason for care, not a diagnosis. For an older horse who hates being left, see our guide to the buddy-sour horse.

Foal weaning age: when is the right time?

There's no single right age, and timing is part of the current debate.

• Common practice: Oklahoma State Extension says most management systems wean between 4 and 6 months.
• In feral herds: Mares naturally wean foals at around 8 to 9 months, per Oklahoma State, or around a year or older, per World Horse Welfare.
• Gradual, welfare-led approach: World Horse Welfare suggests gradual weaning can start at around 8 to 10 months.

Age is only part of the decision. Look at the foal's health, whether it already eats forage and feed well, how tightly it's bonded to the mare, and the mare's own body condition.

Oklahoma State notes that waiting until about 6 months may give a sturdier foal with less social upset than weaning earlier. Your vet may suggest earlier weaning if the mare is losing too much condition or the foal isn't growing well.

A step-by-step weaning plan for families

4 to 8 weeks before

1. Book a vet check for mare and foal, and ask about vaccine and deworming timing so it doesn't land on weaning week.
2. Teach basic handling: haltering, leading, picking up feet and grooming while the foal is still at its mother's side. Our groundwork pages can help.
3. Make sure the foal eats on its own. Foals already used to their ration tend to keep eating through weaning. Ask your vet what to feed, and see our nutrition basics.
4. Walk the fences. Fix gaps, loose wire, protruding feeders and anything at hoof or head height.
5. Line up a nanny: a quiet older mare or gelding who is kind to youngsters.

Weaning week

1. Pick calm weather. Avoid extreme heat, storms and the same week a colt is gelded.
2. Move the mare, not the foal, so the foal stays in its familiar paddock with friends.
3. Start with contact across a safe fence or within sight, then add distance over days.
4. Watch closely, especially for the first 12 to 24 hours, as Oklahoma State advises.
5. Keep water and forage available at all times and note how much the foal eats and drinks.

After weaning

• Weight-tape or photograph the foal weekly and track condition with our body condition score guide.
• Keep the foal with company for good. Horses shouldn't live alone.
• Check the mare's udder daily. Most mares settle faster than their foals.

Weaning stress in foals: what's normal and when to call the vet

Some protest is normal. Expect calling, pacing, some fence-walking and a day or two of smaller appetite.

Signs to watch, from World Horse Welfare and Oklahoma State:

• Repeated whinnying back and forth
• Running or pacing the fence line
• Trying to get through or over fences
• Loose manure or diarrhea
• Aggression toward other horses or people
• Eating less

If reactions are extreme or drag on, World Horse Welfare suggests putting the groups back together and trying again when the foals are older.

Call your vet if you see

• Not eating or drinking for more than about a day, or signs of dehydration
• Weight loss or a foal that looks noticeably thinner
• Any injury from running fences, especially cuts, swelling or lameness
• Colic signs: pawing, rolling, looking at the belly or no manure (see colic signs)
• Diarrhea, fever, cough or nasal discharge, since stressed foals can be more vulnerable to infection
• Nonstop pacing for more than a day or two without settling
• In the mare: a hot, hard or painful udder several days after weaning, or a fever

What to do and what to watch next

The Nottingham paper is a call to action, not a new rulebook. Oklahoma State points out that long-term studies comparing weaning methods are still missing, so expect more research and plenty of debate among breeders and vets about timing.

For your farm this fall:

• Choose gradual and social over abrupt and alone.
• Plan the nanny horse and fix fences now.
• Talk to your vet before weaning, not after a problem.

New to foals? Start with how horses give birth and our care guide.