People frequently ask me how I introduce a new horse to the herd. Over the past 5 years I have had a dozen or so rescues and foster care horses of one breed or another to integrate (or not) into the herd. Every horse is different and there are lots of things to consider. So far, I can say I have not had a single injury integrating a new horse…not even a patch of lost hair.
The first thing to consider is the health of the new horse. Where did they come from? Are they likely to have been exposed to something infectious? Animals coming from an auction or other high traffic facility, no matter how healthy they look, should have a suitable period of quarantine from your herd. This ought to be in a separate barn and turnout, some distance from the home crew. I don’t have such a set-up here, so I am pretty careful about where I will take horses from. I did take on a mini stallion from an auction a couple of years ago and kept him in the spare stall across the aisle from my horses for a month, but this was not ideal and I was probably just lucky. The newest addition, Ripple, came from a rescue organization who quarantined him for 30 days and had him on their premises for 2 months, so much less risk there, though not zero. Unhealthy horses are not only a risk to the health of your herd, they integrate poorly and if integration happens too soon, they can become permanently culled. If major weakness, either from injury, malnutrition or metabolic issues are present, it is much better to get the horse healthy before trying to integrate fully into a stable herd. Better to offer the companionship of a goat, mini or other low on the totem pole horse until they are ready. I will put these horses in an adjoining paddock and allow introductions over a safe, electrified fence until they are ready (if ever) to go mainstream.
The next thing to consider is the temperament of the new horse as well as the already present herd dynamics. Is the new horse confident or unconfident? Are they reactive? Do they respect boundaries? Or push into pressure? Do you have a good idea about how your horses will respond to a newcomer? Is there a stable alpha? Are there any aggressive tendencies or extreme behavior in the current herd members? The major early complication when integrating a new horse, is injury. Horses start sparring, chasing, biting, kicking, etc. You definitely want to know ahead of time if the new horse is likely to go through a fence or jump a gate when the pressure gets high. Make sure they respect boundaries, personal space and yield to pressure before you put them in a tricky position. If the new horse doesn’t have these skills, teach them first. If you have an extreme horse already in your herd, this can complicate things as well. Generally, if there is enough room, plenty of hay, and no place for a horse to get cornered, horses will quickly and safely sort out their order in the herd.
I have a track modeled after Jaime Jackson’s Paddock Paradise and use it exclusively in the winter, which is when most of my rescues arrive. Its a great format to introduce new horses as it is a big circular track. The horses can move along it endlessly promoting exercise and the illusion of wide open space. Its hard for a horse to get cornered in this type of setting. When introducing a new horse, I do it gradually. I usually turn them out in a separate area with each of the herd members, one at a time to assess any surprising aggression. When I do finally turn the new horse out onto the track with the herd, I make sure I will be home all day and plan to be nearby to intervene if anything extreme happens. For the first week to month, depending on the horse, I will bring them into the barn at night to eat and rest without the pressures of herd dynamics. It allows me a place to assess their appetite, hydration and for injuries. Most of these new horses have special diets I concoct for them, so it is easier to separate them from the others for feeding. It also gives me an opportunity to interact with the new horse in the context of the herd. I am part of the herd too. If I remove myself from the integration process, I might find I have have been replaced as leader the next time I walk among my horses. I spend plenty of time out with the herd and new herd member, moving horses around, simply to remind them that I’m still in charge. Its no fun to have one of your trusted steeds push the new horse over the top of you….trust me, been there, done that. I pay attention to body language. Even my quietest horse can become unpredictable when herd politics are in negotiation.
There is a general pattern of integration. I look for certain landmarks to assess progress towards full integration. Sometimes it takes a day, sometimes a month or more.
The first landmark is what I call ‘the greeting’. Sometimes this happens well in advance of the horse actually joining the herd and occurs over the fence line. The horses put their noses to each other for a few seconds to moments. Necks are arched and there is sometimes some squealing or stomping of the feet, but in general no contact. Its kind of like the knocking of the gloves by boxers before they go back to their corners to strategize before a fight.
The next three landmarks can occur in different order, depending on the horses, but they all generally occur. I’ve listed them in the order I typically see. ‘Avoidance’. Some horse just pretend the new horse doesn’t exist. They don’t engage positively or negatively. ‘Pushing’. This is the one everyone hates to watch. The new horse generally gets pushed around mercilessly. If he is lucky, he’ll get it from one horse at a time, but I have seen two horses pushing a newbie at one time. This is really important to the existing herd and is completely natural. This is, however, the time when you want to be sure there is plenty of space to run and lots of piles of hay out. You don’t want horses fighting over food. ‘Sparring’, which is my favorite. Here, finally you see some engagement that is two sided, not just one. Generally sparring starts with the lowest horse in the herd and works its way up, but not always. But when I see the sparring, I know integration is coming along and this is generally when I start letting the new horse stay out with the herd 24/7.
The last landmark has to do with position within the group. Up until now the new horse will stay on the outskirts of the group. When they move along the track they will either be pushed out in front or follow the group from behind. When I see the new horse confidently moving in the middle of the herd (at least some of the time) without getting pressured from the other herd members, I know integration is nearly complete.
The finer points of where the horse fits into the pecking order takes months and alot depends on the health and confidence of the new horse. Our newest herd member, Ripple is on his way to full integration, but its going slowly for him. Slow and right, beats fast and wrong though.

Manny and Ripple were sparring a few minutes before this photo, and now you can see that even though Ripple is still on the outskirts, he is getting much closer to the center of the group...
Anyway, that’s how I do it. I believe horses should live as a group, outside 24/7. They all have access to shelter and the choice to where they want to be in a snowstorm or during the summer heat.
What a timely post on herd integration. I am expecting a new herd member any day and I found your info valuable.
Thanks
Welcome, Rick. Good Luck with your new horse…a youngster?
When & how to integrate into an established herd.
Hi – I live in EnglandI have bought a 5yo PRE – Spanish gelding who arrived from Spain 2weeks ago. He was only gelded in January 2011, and seems to have all the stallion like behaviours (high pitch squeal, kicking, sniffing, mouthy/nippy, excitable around mares). I turned him loose in the small side paddock after 4 days and he got bitten by the Alfa horse over the fence, and jumped and smashed through the fence to be with them. The Alfa horse put him on the floor, and luckily the Spanish cantered back to me and I put him in his stable very shaken. (Had vet out to check – he was fine). So, since then, he has just been on a long line sniffing the others once a day over the fence. Still thrashing and prancing and squealing, but settles. There are 11 horses in total. 5 mares and 6 geldings. There is a top mare and an overall Alfa gelding. (The Alfa gelding is build like a bull – literally, and he is very aggressive). When and how should I integrate the new Spanish? I cannot turn him out in the small paddock as he tries to jump out – just crashes over the thin wood fence, even with a pony for company. Help please??
Sorry, Vikki, for some reason this post did not make it to my email. You have likely integrated your spanish horse successfully by now. But just for other folks listening in…I would have picked a member of your herd to pair with the spanish horse. One that is in the middle of the herd…not too high up and not too low down in the pecking order. Let the two horses bond for a few days, then put them out in the main herd together.
This publication has inspired me to continue writing on my own blog