Weaving in Horses: Causes, Signs and How to Manage It

Weaving in horses is the side-to-side rock you see over a stable door: the horse stands still, shifts its weight from one front leg to the other and swings its head and neck in time. It is one of the best-known locomotor stereotypies, and it is a coping response, not a bad habit. This guide sets out what the research actually shows about why horses weave, which management changes reduce it, why UK welfare charities now advise against anti-weave grilles, and when a weaving horse needs a vet.

Much of what circulates online about weaving, from exact sways per minute to tidy prevalence ranges, does not trace back to a study anyone can read. Where we quote a figure below, it comes from the paper itself and we name it, so you can check it.

What Is Weaving in Horses?

The British Horse Society describes weaving like this: standing still, the horse will "move their weight from one leg to the other while swinging their head and neck from side to side". It is "commonly seen over a stable door, although some horses may weave in any environment". That last point matters. A horse weaving in the field, at the gate or on the yard is doing the same thing, usually while it waits for something or has lost sight of its companions.

Weaving is a stereotypy: a repetitive, fixed pattern of behaviour with no obvious goal or function. The BHS splits stereotypies into two families:

• Locomotor stereotypies, which involve movement: weaving, box walking and head tossing.
• Oral stereotypies, which involve the mouth: crib biting, wind sucking and self-mutilation such as repeated nipping at the body.

Box walking is weaving's closest relative. Our equine-disease entry on stall walking syndrome covers the same behaviour under its American name. Both are tied to movement and confinement, whereas crib biting and wind sucking are more closely linked to diet and gut comfort.

Is Weaving a Stable Vice?

Traditionally, weaving was filed under stable vices, alongside crib biting and box walking. World Horse Welfare notes that these behaviours "were viewed as undesirable behaviours or 'vices' by owners", and now describes them as coping mechanisms that develop when a horse's basic behavioural needs are not met or when it is under prolonged physical or emotional stress. Speaking to Horse & Hound in 2021, Gemma Pearson, director of equine behaviour at The Horse Trust, put it plainly: "In horses, these are coping mechanisms for stress, which usually comes from an abnormal environment", and they are not caused by boredom. The word vice suggests the horse is misbehaving. It is not.

Is It Weaving or Something Else?

Not every repetitive movement is a stereotypy. The BHS draws a useful line: behaviour that is "reinforced and goal-directed" is not a stereotypy. Its example is a horse kicking the stable door at feed time, which is a learnt attempt to hurry the feed along. A horse that shifts its weight about because it is sore is different again, which is one reason the BHS says to "always speak with your vet if you spot the onset of any stereotypy".

How Common Is Weaving in Horses?

Many articles quote a neat percentage range for how many horses weave. We could not trace those ranges to a paper we could read, so we do not repeat them. Here is what the primary studies we could check actually report:

• Young Thoroughbreds, followed from birth. Waters, Nicol and French at the University of Bristol followed 225 young Thoroughbred and part-Thoroughbred horses for four years, 1995 to 1999 (Equine Veterinary Journal, 2002, PMID 12357996). Abnormal behaviour of some kind affected 34.7% of them. Weaving was started by 4.6% of horses, at a median age of 60 weeks. Crib biting (10.5%) and wood chewing (30.3%) were more common.
• How yards handle it. McBride and Long of the University of Wales, Aberystwyth surveyed 100 racing stables, 100 riding schools and 100 competition yards, 8,427 horses in all (Veterinary Record, 2001, PMID 11467606). Stereotypic behaviour was physically prevented by 77, 67 and 79 per cent of them respectively. That survey is about what owners do, not how many horses weave, but it shows how ordinary the problem is on working yards.
• Risk factors across a whole country. Bachmann, Audigé and Stauffacher surveyed owners of 2,341 Swiss horses (Equine Veterinary Journal, 2003, PMID 12638792) to find what made crib biting, weaving and box walking more likely. Their findings are in the causes section below.

What Causes Weaving in Horses?

There is no single cause. Weaving develops when a horse's management repeatedly blocks something it is strongly motivated to do: move, forage, or be with other horses. World Horse Welfare lists the potential causes as "restricted turnout, limited social contact, lack of forage in their diet, and insufficient chewing time", and the studies line up behind each one.

Long Hours in the Stable

McGreevy and colleagues at Bristol surveyed flat racing trainers about 22 yard and management factors (Equine Veterinary Journal, 1995, PMID 7607155). Their headline finding was that "management factors related to the time spent in the stable showed the strongest associations with stereotypic behaviour". In the Swiss study, horses without daily pasture had increased odds of crib biting, weaving and box walking. And in the Bristol young-horse study, youngsters housed in barns rather than at grass after weaning developed abnormal behaviour at a higher rate (rate ratio 2.54).

Not Enough Forage

McGreevy's racing survey found that the risk of abnormal behaviour increased "as the amount of forage fell below 6.8 kg/day", and also when hay rather than other forage was fed. Be clear about what that figure is: a threshold that emerged from a 1995 survey of racehorses on racing rations, not a feeding target for your horse. The Swiss authors drew the same lesson from their own data and recommended "high amounts of roughage but of little or no concentrates".

For setting your own horse's daily forage, start from its weight and condition, not from a stereotypy study. Our horse feeding guide covers the basics.

Too Little Contact With Other Horses

Weaving is closely tied to what a horse can see and touch. McGreevy found the risk rose "in association with box designs that minimised contact between neighbouring horses". The Swiss authors concluded that prevention should be based on housing that allows "tactile contact with other horses (e.g. mutual grooming)".

The neatest test comes from Cooper, McDonald and Mills (Applied Animal Behaviour Science, 2000, PMID 10856785). They moved ten warmblood-type horses, five of them reliable weavers, through five versions of the same 12 x 12 ft loose box. Compared with the usual arrangement of only the top front door open, weaving fell when a side panel was opened into the next stable, and when the front, back and both sides were all open. Opening only a back window onto the fields reduced head nodding but did not reduce weaving. The view a weaver wants is of other horses.

Anticipation: Feed Time and Turnout

Every yard knows the pattern: the weaver starts up when the feed buckets rattle or when the first horses go out. Cooper's study recorded exactly that. Weaving "was most common prior to feeding in the morning and prior to putting out to pasture in the afternoon". In the Swiss study, horses fed four times a day had increased odds of stereotypies, which fits the idea that every meal is one more event to wait for.

Weaning and the First Two Years

The BHS says that "many stereotypies" are established "during the first nine months of life", and that foals stabled throughout weaning and isolated from horses of a similar age are much more likely to develop one. The Bristol cohort backs this up: weaning by confinement in a stable or barn was associated with a higher rate of abnormal behaviour than paddock weaning (rate ratio 2.19). Weaving itself tended to start later than crib biting, at a median of 60 weeks against 20 weeks, so the way a weanling spends its first winter can show up in the yearling. Our guide to weaning a foal covers paddock weaning in practice.

Breed and Temperament

The Swiss study found that "mature Warmbloods and Thoroughbreds, assessed by the owners to be reactive" had increased odds of crib biting, weaving and box walking. That matches what yards see in Thoroughbreds and warmbloods such as the Dutch Warmblood. Breed may carry some inherited tendency, but these are also the horses most likely to live a racing or competition routine with long hours in a box and concentrate feeds. Breed is not something you can change. Management is.

Pain and Gut Discomfort

The BHS gives gastric ulcers as an example of the physical stress that can sit behind a stereotypy, and says new behaviour patterns "can indicate underlying health problems". A horse that starts weaving out of the blue, particularly a settled older horse, deserves a health check before you change anything else. Our guides to ulcers in horses and equine gastric ulcer syndrome cover the signs to look for.

Do Horses Copy Weaving?

Many yards still put a weaver at the end of the row, or out of sight, so that the others do not pick it up. The evidence does not support doing that. The BHS states that "there is no evidence confirming that stereotypical behaviours can be developed just from one horse observing another", and advises against isolating horses that show them, because isolation adds stress and "may lead to the development of new stereotypical behaviours".

The best-known test of copying is for crib biting rather than weaving. Albright and colleagues' US survey (Equine Veterinary Journal, 2009, PMID 19642405) found that "only 1.0% of horses became affected after being exposed to a crib-biter". We are not aware of an equivalent study for weaving, so the honest summary is that there is little evidence horses learn stereotypies by copying, not that copying has been disproven. Horses on the same yard often weave for the same reason: they share the same management.

The copying belief still shapes how weavers are kept. In McBride and Long's survey, affected horses were kept separate from other horses by 39, 30 and 48 per cent of racing stables, riding schools and competition yards respectively, and some establishments would not allow them on the premises at all.

Is Weaving Bad for Horses?

The BHS lists the physical risks of stereotypies as including overdevelopment of particular muscles, weight loss "as some would rather carry out their stereotypical behaviour than eat", and, for weaving specifically, "increased strain on tendons and ligaments". We could not find a study measuring how often weaving leads to lameness or injury, so treat these as risks to watch for rather than measured outcomes.

The bigger issue is what weaving tells you. World Horse Welfare links stereotypies to altered brain physiology and the release of hormones such as dopamine, and Gemma Pearson told H&H that performing these behaviours "releases endorphins, which makes them feel better". That is why simply stopping the movement fixes nothing: the pressure behind it is still there. If your horse weaves, use it as a prompt to look hard at its day. Our overview of the behaviour of horses and our guide to anxiety in horses help with reading the rest of the picture.

Things worth keeping an eye on in a regular weaver:

• Body condition and appetite. Is weaving starting to replace eating?
• The front feet and shoes. H&H was already noting in 2000 that weaving "may cause excessive wear on the front feet".
• The legs, especially after long spells in the stable. Look for heat or filling around tendons and ligaments.
• How much of the day the horse spends weaving, and whether that is rising or falling as you change its management.

Buying a Horse That Weaves

A weaver is not automatically a bad buy, but it does affect value in many people's eyes: in McBride and Long's survey, 45, 59 and 31 per cent of racing, riding-school and competition establishments said stereotypic behaviour reduces a horse's monetary value. Ask the seller when the horse weaves, how much and in what setting; watch it in its box around feed time; and be honest about whether you can offer more turnout and company than its current home. If you keep your horse at livery, check the livery yard's rules before you buy, since some yards still fit anti-weave grilles as standard.

How to Stop Weaving in Horses

Stopping the movement is the wrong goal. World Horse Welfare is explicit that management "should never restrict the horse's ability to perform the behaviours, as they are important coping mechanisms", and that once a stereotypy is established it "may never fully go away". The realistic aim is to take away the pressure that drives it, so the horse needs it less. World Horse Welfare sums up what to aim for as "the 3Fs: friends, forage and freedom", and the BHS gives the same list under environment, enrichment, companionship and forage.

1. More Turnout, With Company

World Horse Welfare's advice is that horses "should be turned out for as long as possible, ideally with at least one other horse". The studies agree: daily pasture lowered the odds of weaving in the Swiss survey, and grass rather than barns after weaning lowered the rate of abnormal behaviour in the Bristol cohort. If grazing has to be restricted for weight or laminitis reasons, the BHS suggests alternatives such as an arena, a secure lunge pen or an alternative grazing system, so the horse can still move with other horses without unlimited grass. Our guide to turning out a horse covers the practical side, and keeping turnout groups settled matters as much as the hours.

Speaking to Horse & Hound in 2004, Professor Daniel Mills, a vet and behaviour specialist at the University of Lincoln, said reduced exercise may be linked to weaving and box walking, and that horses kept in paddocks of less than 1.5 hectares do not show the full range of equine social behaviour. That 1.5 hectare figure is about social behaviour. It is sometimes quoted online as a weaving threshold, which is not what he said.

2. Open Up the Stable

This is where the experimental evidence is strongest. In Cooper's trial, opening a side panel into the next box cut weaving; a view of the fields alone did not. In a second small study, Mills and Davenport gave six weavers a grilled window to a non-weaving neighbour, and weaving was significantly lower than in an unmodified stable. World Horse Welfare's advice is that "stables should allow visual contact with other horses as a minimum, and ideally some form of physical contact so that they can participate in mutual grooming".

Layout matters. In a single row of boxes under one roof, the arrangement racing yards call a shedrow, a horse at its door can usually see the yard but has little contact with the horses either side unless the partitions allow it. That is close to the top-door-only box Cooper's team used as their baseline. If two neighbours get on, a grille in the partition between them is the change both of these studies point to. Our guide to designing a stable covers layouts that keep horses in sight of each other.

3. More Forage, Eaten More Slowly

Keep forage in front of a stabled horse for as much of the day as its weight allows. A small-holed hay net or hay ball stretches eating time, and Professor Mills suggested putting "feeding stations" around the box instead of feeding in one place every day. For a good-doer, the aim is slower eating rather than more calories. Swap concentrate for fibre where you can, in line with the Swiss authors' recommendation of plenty of roughage and little or no concentrate. An equine nutritionist can help you build a high-fibre ration that holds weight without hard feed.

4. Try a Stable Mirror

Mirrors are the best-studied single fix for weaving. McAfee, Mills and Cooper (Applied Animal Behaviour Science, 2002) fitted a 1 m x 1.5 m mirror for five weeks in the boxes of six weavers and found it significantly reduced weaving. Mills and Davenport (Animal Science, 2002) then compared a mirror against that grilled window to a real neighbour: weaving was significantly higher in the unmodified stable, and there was no significant difference between the mirror and the neighbour.

Two caveats. Both studies used six horses, so they show a mirror can work, not how well it will work for yours. And Professor Mills himself told H&H in 2004 that "mirrors seem to be more effective with box walking than weaving", and that his team had found large posters of horses could have a calming effect too. In practice:

• Use an acrylic safety mirror made for stables, never household glass.
• Fit it where the horse can see its reflection from where it usually stands to weave.
• Introduce it gradually and watch the first sessions. Take it down if the horse reacts aggressively to its reflection.
• Treat a mirror as an addition to more turnout and company, not a replacement for them.

5. Enrichment and a Less Predictable Day

The BHS describes enrichment as something that "creates a greater variety and choice" for the horse, from hay balls that slow eating to time out of the box for hand grazing and exercise. Our guide to toys, treats and turnout has practical ideas. Because so much weaving builds up before meals and turnout, it can also help to feed the weaver first, give a small amount of forage before hard feed arrives, and avoid long, predictable gaps with nothing to do.

Why Anti-Weave Grilles Are Not the Answer

The V-shaped anti-weave grille stops the head swinging over the door. It changes where the horse can put its head, not why it wants to weave. The BHS says devices such as cribbing collars and anti-weave grilles "do not address the root cause of the horse's anxiety and can cause or exacerbate stress, potentially causing them to adapt their stereotypical behaviour or in some cases develop new ones". World Horse Welfare is blunter: products aimed at physically preventing stereotypic behaviours, "including anti-crib biting collars and anti-weave grills for stables, should not be used".

Advice has changed within living memory. An H&H horse-care article from 2000 said a V-shaped grille on the door "usually controls the behaviour". By 2004 the magazine was reporting that researchers now said grilles and cribbing collars "can cause more harm than they prevent". If your yard insists on a grille, raise it with the yard manager and show them the BHS and World Horse Welfare guidance.

What About Medication?

We could not find a published drug trial for weaving. Where pain, such as gastric ulcers, is part of the picture, treating it is your vet's job, and any medication is a veterinary decision. A sedative or behaviour-altering drug is not a substitute for changing the horse's day.

Weaving in Ex-Racehorses and Competition Horses

McGreevy's 1995 study of stereotypy risk factors was a survey of flat racing yards, and McBride and Long's survey found racing stables physically preventing stereotypic behaviour in 77 per cent of cases. A horse coming out of training has often spent years with long hours in a box, concentrate rations and fixed feed times. Many settle well with turnout, company and forage, but the BHS warns that a stereotypy may continue as a habit "even if they are moved into a suitable environment", so judge progress by how much less the horse weaves, not by whether it stops. Our guides to racehorse retraining and the Thoroughbred cover the wider transition.

Racing itself relies on calm company to settle highly strung horses: a lead pony walks a keyed-up runner to the start for exactly that reason. At home, a steady companion horse in the next box and in the field does a similar job for a newly retired weaver.

Preventing Weaving in Young Horses

Prevention is far easier than cure, and most of it happens before a horse is ever ridden. Based on the Bristol cohort, the Swiss survey and the BHS guidance:

• Wean in a paddock, in company, rather than by shutting the foal in a stable. Stable or barn weaning was associated with a higher rate of abnormal behaviour (rate ratio 2.19).
• Keep weanlings and yearlings at grass with horses of a similar age rather than housing them. Barn housing after weaning raised the rate further (rate ratio 2.54).
• Feed plenty of forage and keep concentrates to a minimum. In the same cohort, feeding concentrates after weaning was associated with a fourfold increase in the rate of crib biting (rate ratio 4.12).
• Remember the timescale. Weaving started at a median of 60 weeks in the Bristol study, long before most youngsters are broken in, so prevention happens in the field rather than in the school.

When to Call Your Vet or a Behaviourist

Speak to your vet if:

• The weaving is new, or a horse that weaved a little is suddenly weaving a lot. The BHS advice is to rule out a physical cause first.
• The horse is losing weight, leaving feed or drinking less than usual. Our guide to dehydration in horses covers the checks you can do while you wait for the vet.
• You see lameness, heat or filling in the legs, or uneven wear on the front feet.

If the vet finds no physical cause and the weaving is not easing despite more turnout, company and forage, World Horse Welfare recommends support from "a qualified equine behaviour professional". Our guide to what a horse behaviourist does explains what to expect from one.

Weaving is not stubbornness, and it is not a habit picked up from the horse next door. It is a horse coping with a day that does not suit it. More time out, more company and more forage will not always make it disappear, but they are what the evidence says will help.

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