Introducing new horses to each other

Presenting a horse to a new herd requires preparation to ensure a smooth process, and prevent injury and stress. Equine behaviourist Justine Harrison explains how to help make introductions stress-free.

Having the company of other horses is a fundamental aspect of good horse welfare. Horses have evolved to be herd animals, living in large groups for safety and companionship. Even in domestic environments horses should live out with other horses; isolating them can cause undue stress and anxiety. If stabled they should be next to horses that they can see and preferably touch.

 In the wild, horses tend to stay in the same herd for most of their lives. With domestic horses there may be times when a horse will need to be introduced to a new group, perhaps through moving yards or being sold. However, introducing a new horse to a herd is not simply a matter of turning him out in the field and hoping for the best.

Check Horse Health First

“Horses may become aggressive when a new horse enters the herd. So it’s important to make introductions gradual to prevent injury,” advises Justine. “A good place to begin is ensuring that the whole herd is physically healthy. This means they are sound, up to date with vaccinations, and free of contagious diseases.”

“A new horse can introduce disease, just as a horse in the established herd can pass on disease to the new horse. A good way to manage the risk of disease is to quarantine the new horse for at least ten days - making sure they can see other horses at all times throughout.”

Allow Plenty of Field Space

Space is also an important factor to consider. In an ideal world, there should be at least one acre per horse to ensure the field is big enough. This helps to prevent resource guarding (fighting over food, friends and water).

 “Plan which field you will use to introduce the new horse – the bigger the better. Then consider potential escape routes for you to safely remove horses if something doesn’t go to plan,” continues Justine. “If possible, lead your horse around the empty field first, showing them the perimeter fence and where the water and feeding stations are.

Introduce Horses Gradually

Consider splitting the herd up into small groups, or even individuals, and introducing your horse to them one-by-one before putting them out as a whole herd. Start by allowing your horse to say ‘hello’ over a stable door or fence before gradually allowing them turnout time together.  

 “Watch how the horses interact with each other and see if some horses react better or worse than others,” says Justine. “You should always start by turning the new horse out into a field next to the other horses for a few days. They can then see each other and meet over the fence. Feeding them beforehand will reduce any food-related anxiety. Wait for the horses to be happily grazing alongside each other on either side of the fence, or even grooming each other, before putting them in together.”

Have Help On Hand

When you feel it’s safe to introduce the new horse to the herd, plan it for a time when most of the other horse’s owners are around to help.

 “With any introduction, the horses are likely to investigate the new arrival, squeal, posture and run about - this is normal,” says Justine. “If there is any sign of fighting or anyone being chased repeatedly, you may need to remove the new horse and reconsider the arrangement.”

Check your horse for injuries and signs of stress that may indicate they aren’t happy in their new herd. It's important to keep a close eye on them throughout the process and take a step back if needed.