When it comes to PSSM & MFM explosive behaviour is something commonly discussed amongst owners. But what is explosive behaviour and why do some PSSM horses react explosively?

What Is Explosive Behaviour?

Explosive behaviour is when a horse reacts unpredictably. Horses who are explosive will often fly off the handle with little or no warning, they also have little or no self preservation for themselves.

PSSM Symptoms Explosive Behaviour
Angel a P1/P1 American Quarter Horse reacting explosively showing no self preservation, angel was seen in videos trying to jump out of her pen, bucking out at fences catching the gate multiple times, and here she reared and hit her head hard

What Is Classed As Explosive Behaviour In Horses?

Explosive behaviour is often unpredictable and can appear as:

1) Bucking
2) Rearing
3) Broncing
4) Bunny hopping
5) Bolting
6) Kicking
7) Completely losing the plot for no reason
8) Showing no self preservation

Why Do PSSM Horses React Explosively?

Pain is the main reason for PSSM horses to react explosively. PSSM can cause horses severe pain, stress and in turn ulcers especially if left undiagnosed. Pain can come in the form of muscle soreness, or suddenly becoming tight during work which is like severe muscle cramps- not all horses who become tight will tye up, which often leads owners to push their horse through it as they think it’s a training issue which can then lead to explosive behaviour.

How Does An Explosive Horse Behave?

The explosive horse behaves unpredictable, they will do things completely random and out of character often leaving you wondering where the hell that came from. The explosive horse may also become extremely stressed on the ground, or have days where they will completely lose the plot for no apparent reason, despite there being no change to their routine, this is because a horse in pain is vulnerable, meaning they will no longer feel safe. The explosive horse may also have no self preservation which means they are not afraid about hurting themselves.

PSSM Symptoms Explosive Behaviour
Chief an N/P2 N/P4 American Quarter Horse gelding showing a great example of an explosive horse losing the plot. Chief was explained as a calm easy going horse and this was completely out of character for him, chief was euthanised in 2020

When Does Explosive Behaviour Affect PSSM & MFM horses?

Explosive behaviour most commonly occurs during exercise under saddle. But it can also be witnessed in the horse on the ground during lunging, or in the field.

Can A Horse Be Naturally Explosive?

No a horse can be naturally hot or excited but not explosive. There is a big difference between a horse feeling his oats and being excited, to a horse displaying explosive behaviour. Excitement will be the odd buck, a head toss, a spring in the air, all signs a horse is feeling good, but explosive behaviour is unpredictable, the horse will completely change character in an instant and it will feel like the horse really means it, if under saddle the horse won’t usually stop until the rider has hit the deck. This is often scary for the owner as it catches them completely unawares.

PSSM Symptoms Explosive Behaviour
Aspen a horse with PSSM1 & PSSM2, in the video Aspen can be seen trotting happily but when asked to canter he bolts and explodes into a fit of repeated bucking

How Can We Stop A PSSM Horse Being Explosive?

The best way to stop a PSSM horse being explosive is to get your management spot on. With PSSM & MFM there is not a one size fits all in regards to management, there are guidelines of what to feed but how much depends on your horse, some horses will need much more, or much less than others of specific supplements so its about finding out what works for your horse, and really tailoring their diet so it’s unique to them.
But management can only help the physical scars, a PSSM horse who has been explosive for a while may have mental scars especially if they’ve been pushed through the pain for a while. So a slow rehab plan with patience, compassion, and understanding will need to be put into place not all PSSM horses who have been explosive will be able to recover from the mental scars, but some do.

For more information on the PSSM symptom Explosive Behaviour check out our YouTube video with examples of affected PSSM horses by clicking this link