Freezing with Dr. Andrew McLean

Story from March 2019 Horse Deals magazine

You have probably gathered that this is not about a method of preserving food. Horse Deals spoke to Dr McLean, founder of the Australian Equine Behaviour Centre (AEBC) and director of Equitation Science international (ESI) to find out about the horse behaviour known as freezing. We do not just mean a horse refusing to do something, or go somewhere, we mean the rather scary behaviour of the horse standing wide eyed, rigid and immobile. Many readers will have experienced this behaviour, and like just about everything there is an explanation, and animal behaviour specialist Dr McLean was the one to ask.

We hear a great deal about the horse’s flight instinct, but very little about the freeze instinct. Both are connected with the same instinct in mind, self preservation.

“Some behaviour can be mistaken for the freeze mechanism,” begins Dr McLean. “An animal can become apathetic and not respond to stimuli; a learned helplessness that often shows up as a passive coping mechanism, which looks like freezing, as the horse has totally shut down. It can be that the animal has actually learned that if it simply stops what you are asking it to do; like it just stops dead, the rider stops asking. So there is a gap, a release of pressure before the rider decides to do something else. The freezing is actually rewarded by the ceasing of activity by the rider. So quite often, the horse learns not to go forward, like most things, by the mistakes in using pressure-release. For example, not stopping the pressure when you get the right reaction. This is not a classic freeze reaction, but simply stalling and standing still is a solution for the horse.

“There is also the jacking up response from a horse because it has learned that it doesn’t really have to go, but that is also not a classic freeze.

“Then there is a real freeze which is a typical response of a prey animal, just like the flight response which is connected with an active coping mechanism, not a passive one. Freezing is connected with high sympathetic nervous system activity where the heart rate and blood pressure are raised (the Sympathetic Nervous system is part of the Autonomic Nervous System responsible for control of bodily functions not consciously directed i.e. breathing, heartbeat, the digestive system). Learned helplessness is associated with a lower heart rate and blood pressure and is a passive coping mechanism.

“In a prey animal when fight doesn’t work and flight doesn’t work, freezing is another hyperactive sympathetic response, where they adopt Tonic Immobility (a natural state of paralysis) where the whole body does not move at all. Quite often with big cats, when the prey animal does not react and run, the killing instinct is not stimulated. Also big cats suffocate their prey by putting their mouths over the prey’s mouth or grabbing its throat and shutting down its breathing and when it no longer reacts, they let go. So freezing is a really good adaptation to dupe the predator into thinking to let go and the prey can suddenly leap up and run off. Plenty of people have seen this in the wild, and that is why it has evolved in animals.”

So why does a domesticated horse freeze in that way when we are riding it?

“I think quite often they freeze for similar reasons. When they are subjected to high levels of fear and confusion for instance using a whip and they can’t give a reaction to cease it, or they don’t have the correct reaction in their array of responses, because it has not been reinforced in the past. Freezing is an option to high levels of sympathetic nervous activity. The real freeze where they stop and go rigid is more common in the hotter breeds. You can also get a Tonic Immobility reaction and consequent violent reaction from a nose-twitched horse. It can suddenly panic and react violently to free itself.

“With the classic freeze response which can be followed by a violently energetic act as a means of escaping the predator, the best thing to do is get off. The next best thing to do is to turn them if you can, which may pull them out of the freeze, but it may also elicit a violent response. I have suffered major injuries from horses displaying this behavior and I would not recommend anyone dealing with that; staying on is courting danger. Get off and start all over again and maybe check out your ground work (I’d say there are bound to be faults there). Train your horse in hand, which I think everyone should do. Without moving your own feet, get the horse from a very light aid to step forward and back and stay in a parked position. If it will do those three things in hand, when you get a fractious horse and you get off, quite often you will wake it up into a better reaction and you may be able to hop back on and get it moving again.

“Easier to understand is the freeze reaction the horse may give when it gets a fright, for instance a kangaroo bounds across its path. The horse freezes, the heart rate increases as evidenced by its heart just about jumping out of its chest. This freeze is often temporary and is a matter of seeing the kangaroo competing with your aid for go (the visual of kangaroo means far more to the horse than you asking him to go forward). When the kangaroo disappears the horse usually recovers. However, it can also provoke a violent flight response.

“In some cases the horse has learned to freeze because there is some confusion in the basic training of stop and go - well trained horses usually don’t freeze. But in saying that, every horse is an individual and some horses will be more prone to freeze than others. Some will never freeze and others will freeze at the drop of a hat. Freezing is just a really ancient basic response and when pain doesn’t lead to an outcome, it’s the plan B solution.”

Sign up to our newsletter