Stereotypies- aka 'Vices' - Do Horses Copy?
Stereotypies, more commonly known as 'stable vices', can come in many different forms of behavioural expression. Such as weaving, crib biting, wind sucking, box walking and fence walking.
They are often formed within one month of weaning, this is due to the changes in environment and nutrition the foal will undergo. Depending on how the foal is weaned, it could also be suggested that stress could be a factor.
Other horses could develop a 'vice' due to lack of forage, lack of equine contact and the inability to roam. It is also suggested that boredom is an instigator, however there is much argument whether horses have the capacity to feel bored as we humans do. Horses are herd animals and are designed to graze and roam for 17 hours a day, eating different grasses and other available forages. Perhaps his version of boredom is the inability to act like a horse should act, his very nature being denied? Now, I am not saying don't stable your horses, there are certainly benefits to stabling a domestic horse, providing he gets the forage, equine contact and freedom he needs.
The next question is, do horses copy stereotypies from each other? In short, no, they do not. There have been no reports or proof that they copy, however, many members of the equine world are under the impression that they do. Many livery yards won't even take a horse that wind sucks or weaves because of this. I have been running a livery yard I built for 11 years now, and in my yard I have two types of stables. In the barn, there are 11 loose boxes. The horses can touch each other over the walls and they can always see other horses when stabled. A few are not suited to this type of stabling as they argue with the horse next door so have often built up higher walls for these horses. The majority, however, are much happier in this setting. I have had many different horses come through over the years, among them have been a lot of racehorses and I always stable them in the barn. A lot of racehorses have vices of some description, this is due to the nature of training meaning the horses are stabled for long periods, and have a low forage diet. These are environmental factors, not because they are copying each other. They are all experiencing the same 'motive' to express a need written in their DNA. The other answer is it all stemmed from weaning.
In my experience in retraining racehorses at my yard, in my barn where they can all see each other, I have never once had a horse copy a vice from another. Some horses that have come to me as weavers and wind suckers would actually reduce these behaviours over time. One of the horses I sold recently after retraining rarely does it at all now I’m told.
Sadly some are too severe to stop. In January 2019 I bought a thoroughbred filly from Ireland, unseen (yes, I know, mad). She was advertised as a 14.2 3 year old, well handled filly. She arrived at 7am in the morning on the 29th, after waiting all night in my lorry for her to arrive I might add! Off came a very poorly pony. She was emaciated, covered in dermatitis, lice, heavily scouring, sarcoids, and she wind sucked for a pastime. I named her Lunita, which means little moon, as she's an iron grey. Today she looks a different animal, but still wind sucks, she even does it in the field, although not nearly as much as she used to. I would like to add that none of my other horses have 'copied'.
Older horses can still develop stereotypies, however. A few years ago I had a polo pony I was playing and selling for a client. My client had owned this horse for many many years, and the pony was very well known at the polo club. While I had the pony he never showed any signs of vices. The gelding went away on a two day trial, passed a 5 stage vetting and a purchase price was agreed. Two weeks later I got a call from the new owner saying the horse wind sucked. This came as quite a shock as I had not seen him wind suck over the months I had him, and my client confirmed he had never shown this or any other vice before. This was also confirmed by the grooms that looked after him for many years. The new owner had commented that the horse was fat when she viewed him, to which I disagreed. He wasn't a skinny thoroughbred type but he certainly wasn't fat. Here is a classic example of environmental cause, the horse was not getting enough forage and being tied up on the pony lines for hours with no food. Some might say he was bored, if horses can be bored.
There are old fashioned methods of preventing horses expressing stereotypies, such as wind sucking collars, and anti weave grills. It is now suggested that preventing the horses express such behaviour is more damaging than allowing them to do it. Wind sucking can cause ulcers but in most cases this can be avoided or treated with the right management.
The best thing to do is allow horses enough access to what their instincts are asking for. The contact and companionship of other horses, to be able to roam, and access enough forage.
For some more scientific reading on this subject, try https://www.paardenwelzijnscheck.nl/app/webroot/files/ckeditor_files/files/Gezondheid%20en%20gedrag/Nicol%20(1999)%20Understanding%20equine%20stereotypies.pdf.