"It Came Out Of Nowhere" Explained By Equine Behavioral Science

Have you ever had a particularly difficult time in your life, where it seemed like you couldn't get a break?

A stressor here, a stressor there. Family troubles. Health issues. Financial strain. We all go through it at some point.

As the stressors pile on, you're still functioning (somehow). But maybe you're a bit more irritable. It takes you longer to fall asleep. It's harder to let go and have fun. You aren't as energetic.

Then, one seemingly minor inconvenience pushes you over the edge into sadness or rage. To the outside observer, it looks like this reaction "came out of nowhere". Of course, we know it's been coming for some time.

This is called allostatic overload. It's what happens physiologically when the cumulative burden of stress becomes too much for your body to cope with, and all of your body systems become stuck in the stress response (allostatic response). In contrast, a healthy body will terminate the stress response when the stressor has ended. There is an ideal level of stress, a middle area, that keeps the brain and body engaged and active.

So how is this relevant to horses?

Well, how many times have you heard "it came out of nowhere!" in reference to a horse acting out?

Having worked with hundreds of horses, I have found that a large portion of them are stressed. Small, stressful parts of a horse's routine like stalling, infrequent meals, heavy or improper training, travel, & competition all contribute to the horse's allostatic load. Just like humans, some horses cope with stress easier than others. When the horse is not given sufficient rest time between stressful events, this is usually when we see behaviors like weaving, cribbing, & biting or health issues such as ulcers, tense musculature, & weakened immune systems.

Just like us, horses are capable of carrying stress, but their ability to manage it has limits. When their allostatic load exceeds that capacity, it manifests in both behavioral and physical ways. Whether it's tension in their bodies or frustration in their behavior, these signs are their way of telling us that the stress has become too much.

The good news is, just as we can help ourselves manage stress through rest, support, and healthy coping mechanisms, we can do the same for horses. Horses are most content when they have their big 3 taken care of. Forage, freedom, and friends. Maximize these three and cut out unnecessary stressors. You'll have a much healthier, happier horse.

Sources

Pawluski, J., Jego, P., Henry, S., Bruchet, A., Palme, R., Coste, C., & Hausberger, M. (2017). Low plasma cortisol and fecal cortisol metabolite measures as indicators of compromised welfare in domestic horses (Equus caballus). PloS one, 12(9), e0182257. https://doi.org/10.1371/journal.pone.0182257

Seeley, K. E., Proudfoot, K. L., & Edes, A. N. (2022). The application of allostasis and allostatic load in animal species: A scoping review. PloS one, 17(8), e0273838. https://doi.org/10.1371/journal.pone.0273838