Without exception the horses have always handled it just fine. In fact they usually act like nothing has happened. This is because we have what we call the power of group living. The response from the horse(s) left behind would be quite different if a group of 2 or 3 horses lost a member. In that situation a significant part of their herd, and in the case of 2 horses the only part of their herd, is now gone. Horses derive their comfort and security from their herd, and we humans sometimes like to forget that our horses are hardwired to be herd animals.
Often people seem bothered when we tell them the other horses act like nothing changed, especially if it is a horse that their horse was particularly friendly with. Another thing we humans really want is for our horses to respond like we would. When my father passed a few weeks ago I did not move on like nothing had happened, in fact I am still overwhelmingly sad. This is a very different response than the horses have to the loss of a herd mate. To some people when they realize their horses are not reacting this way we think of them as uncaring or mean. Expecting the horses to have a human response, and then passing judgement on them when they do not, is so unfair to the horses.
Sometimes the other members of the herd are fully aware of what happened. If a horse is euthanized at the farm then we try to make sure their herd mates know their friend has passed. On several occasions we have made the decision to euthanize a resident when they are at the vet clinic. Obviously in this scenario the other herd members do not know what is happening. However it has never mattered which set of circumstances applied as the reaction has always been the same, the herd members left behind move on like nothing happened.
Several years ago we had two retired polo ponies, Lacy and Harmony, make the trip to our farm from Canada. These two mares had had the same owner and lived together for something like sixteen years. They had been retired for a couple of years prior to moving to our farm and they lived in a paddock with each other, never being separated for any reason, for a couple of years. When they traveled on the trailer from Canada to Tennessee they rode together in the same box stall. Any time they needed to be stalled they had to be put in the same stall. If there was a physical barrier between them they both flipped out. They always had to be led in and out from the pasture together, see the farrier at the same time, etc. Their owner described them as hysterically bonded and that was a very accurate description.
After joining us for retirement they of course joined a group of retirees. They had been living with their group for about 18 months when Lacy passed away. One morning she did not come for breakfast. Everyone else had come, including Harmony, and were eating like normal. Lacy was found towards the back of the pasture where it appeared she had fallen over dead from a heart attack (Lacy was in her late 20's). After 16 years of being hysterically bonded and flipping out about any level of separation Harmony stood there eating breakfast like she didn't have a care in the world. Just like that she moved on and happily lived several more years.
If that same scenario had played out in the paddock in Canada with just Lacy and Harmony living together I am 100% certain that Harmony's response would have been vastly different because she did not have the security of the herd. We've seen several other examples like this through the years where one horse loses what appears to be his or her BFF. Without any drama or stress they simply move on and pick a new BFF.
The way horses cope with loss is one of the most powerful reminders to me that they are horses and not people. When they are allowed to live in a group environment - as they are hard wired to do - they deal with loss just fine. They are also the perfect example of what a strong social support system can do for you in a time of need.
Norman and Silky
Lily and Traveller
Leo and Levendi
Thomas and Homer
Baby, Moe and Trigger
Stormy and Rampal