06/10/2025
🐴 MENTAL DEFICIT AND NEURODIVERGENCE IN HORSES II 🐴
This topic caught a lot of your attention, so let’s take it a bit further and clarify a few things. Unfortunately, I can’t rely on scientific studies here, as I haven’t come across any research specifically addressing this subject yet. What I share comes from my own experience and observation.
Last time, I used the term mental deficit in a simplified way, but today I’d like to distinguish between mental deficit and neurodivergence.
👉 Mental Deficit
(also called intellectual disability or developmental delay) refers to reduced cognitive abilities compared to the general population – in other words, an actual limitation of brain functions (e.g. in learning, memory, orientation, problem-solving, adaptive behaviour).
In horses:
🟢 it can result from real neurological or developmental damage (e.g. trauma, oxygen deprivation at birth, CNS infection, etc.),
🟢 the horse struggles to learn even simple patterns and repeatedly forgets previously learned responses,
🟢 its behaviour may appear “slow,” uncoordinated, confused, or illogical,
🟢 it often has trouble adapting even in familiar environments (as if “for the thousandth time and still the first”),
🟢 it sometimes reacts inappropriately (e.g. with no clear link between stimulus and response).
With such a horse, this isn’t about “stubbornness” or “defiance” — it’s a limitation of the nervous system, much like in a person with an intellectual disability.
👉 Neurodivergence
refers to a different way the nervous system functions, which isn’t necessarily a deficit. It’s a variation in how information is processed (for example: autism, ADHD, hypersensitivity, PTSD, or trauma-related nervous system reorganization).
In horses, this doesn’t mean reduced intelligence — rather, a differently tuned nervous system:
🟢 they tend to be highly sensitive to stimuli (light, sounds, touch, environmental change),
🟢 they may show atypical reactions — for instance, freezing instead of fleeing, or overly strong responses,
🟢 they learn differently: they respond best to gentleness, consistency, and safety, but may “shut down” under pressure or stress,
🟢 they often display what could be called functional dysregulation — their nervous system shifts between activation and shutdown more quickly and sensitively,
🟢 they react more to emotional tone and the sense of safety than to traditional training cues,
🟢 they can have difficulties with social interaction — for example, forming bonds with other horses or humans can be challenging.
Such a horse can be highly perceptive, intuitive, and intelligent, but it requires a different approach — one that respects its neurophysiology.
💬 What does this look like in practice?
🐴 A horse with a mental deficit can learn the basics but may never be reliable in complex tasks, can appear slow or “absent,” and needs a consistently simple and stable environment.
🐴 A neurodivergent horse perceives emotional nuances very well but gets overwhelmed easily; it reacts to micro-movements of the human body and needs to feel certainty and safety.
Do you have a horse like this at home?
In the next post, we’ll talk about how to work with them.
K.