I am SO sick of seeing posts/jokes about horses who “Play dead” when asked to do something simple, like being tacked up or wearing a blanket. What’s horrifying is that there is nothing funny about this. This is a deeply traumatic event for the horse and seriously dangerous for everyone involved!!
Tonic Immobility is “Muscular paralysis that occurs during significant stress or injury, e.g., as an animal is fleeing or trying to fight off a predator. It is a common reaction experienced by animals and humans faced with overwhelming force, e.g., in battle or during sexual assault.” (https://medical-dictionary.thefreedictionary.com/tonic…)
This is no mild emotional response, this is a complete body shut down. Only the basic survival systems carry on – heart rate, respiration, blood pressure, digestive systems all lower, the muscles become paralyzed and either rigid or limp, the mind goes blank (from human testimonies). There are many theories for why this exists, but it seems to be a final defense when fight or flight are not an option (in the mind of the victim – there may be an apparent escape that the victim can’t utilize). This technique is a last resort to spare the mind of the suffering of the inescapable horror happening to them. Humans who have survived these experiences often feel like it is an out of body experience, or feels surreal, or even can’t remember the time they were paralyzed, just the extreme horror they felt. This phenomenon can be life saving, thus how it likely developed, if a predator has prey in their mouth, and the prey struggles the predator will continue thrashing. While if the prey goes limp the predator may lose interest or get distracted by something happening (another predator or scavenger), reducing the damage done to the victim until a chance may arrive for escape. This is also beneficial in situations where the animal becomes entrapped, going limp reduces the damage done to them while they may slip free or wiggle loose in small, contained bursts, rather than sustained thrashing which can harm them seriously.
This emotional reaction is, I might say, the most extreme reaction to a set of circumstances, an ultimate level of inescapable horror. This is not an emotional reaction to take lightly, to think of as funny, and NEVER should be utilized in training or on purpose.
Often when horses who used to be fine with these things suddenly develop this type of response, they likely have a health issue going on. Some sort of neurological damage or pain inhibiting their ability to escape, intensifying their fear. If a horse suddenly has this response out of nowhere, this is no joke, he hasn’t learned a new trick, this is a SERIOUS health and safety issue for the physical and emotional wellbeing of your horse, and your own safety! You don’t want to be riding a horse who may spontaneously collapse.