Ever wondered why so much of what we do with horses starts on the left? From our earliest riding lessons, it’s usually drilled into us as standard practice:

• Leading from the left
• Tacking up from the left
• Grooming from the left

It’s so normal that many of us never stop to ask why. The answer is a blend of equine vision and behaviour, how horses process what they see, and a hefty dose of tradition.

Instincts and vision: why one side can feel “safer”

Horses have monocular vision because their eyes sit on the sides of their head. Each eye can take in a wide view of the world independently, which is useful for spotting danger, but it also means horses don’t see the world in the same “straight ahead” way we do.

Approaching slightly to one side helps your horse see you clearly and understand what you’re doing. But why the left?

Research into equine laterality (side preference) suggests many horses are more likely to use the left eye when assessing unfamiliar or potentially worrying situations. Because the left eye feeds information primarily to the right hemisphere of the brain, and the right hemisphere is often linked with processing emotion and responding to novelty, the left side can be the horse’s “go-to” view for evaluation.

In practical terms, starting handling on the left can feel more predictable for the horse, which can reduce tension and make learning easier.

Bonding and social cues: the left eye matters

The left side isn’t only about caution and assessment. Studies also suggest horses may prefer to keep familiar social partners in their left visual field.

For example, research has reported that mares and foals often position one another on the left, appearing to favour looking at each other with the left eye. That’s interesting for everyday handling because grooming, catching, and quiet time together are all part of how trust is built.

Horses are also sensitive to human facial expressions and body language. A calm approach, relaxed posture and friendly expression can make a difference, especially when you’re introducing something new (clippers, rugs, injections, loading practice) or working with a horse that’s naturally more anxious.

Tradition: why the horse world standardised the left

Even with the behavioural science, tradition plays a big role.

Historically, horses were handled from the left for practical reasons linked to how people carried weapons and mounted. Over time, the “left side” approach became the industry standard—so most horses are started, led, mounted and managed predominantly from the left.

That familiarity matters. A horse that has been handled from the left for years is likely to feel more comfortable and confident when you repeat what it already knows.

Should you work from the right as well?

Yes, just do it thoughtfully.

Starting on the left is often the easiest way to introduce something new, but it’s still worth teaching your horse to accept handling from the right. This can be invaluable in real-life situations, such as:

• An emergency where you can’t safely access the left side
• Loading or unloading in a tight space
• Treating an injury on the left side
• Groundwork where you want even responsiveness

A simple approach is to begin on the left (where your horse is most confident), then repeat the same calm steps on the right in short sessions—rewarding relaxation and not rushing the process.

Takeaway

We do so much from the left because many horses show a natural left-eye preference for assessment and social positioning, and because centuries of tradition have reinforced left-side handling as the norm.

But the most practical goal for modern horse owners is balance: start where your horse feels safest, then build confidence on both sides.