As we step into February – the final month of meteorological winter, and historically the coldest – many of us notice subtle changes in how our horses cope with the season. Older horses move a little more slowly on frosty mornings, many drink much less, while others lose condition - this is our Carmen - or seem more sensitive to the cold dampness.

We expect winter to be harder on them… but why?

We tend to talk endlessly about the gut, with liver health taking centre stage every spring and autumn for the coat change. And rightly so - the liver is a superhero - the body’s  multi-skilled workhorse getting on with a thousand jobs we never see.

But the kidneys? It’s easy to forget that the kidneys are just as remarkable. In fact, their workload is every bit as exhaustive – and in both functional physiology and traditional systems like TCM, the kidneys shoulder an enormous amount of the body’s winter work behind the scenes.

Despite their central role in regulation, hydration, warmth and energy, the kidneys rarely get a headline of their own. But in both functional physiology and traditional systems like TCM (Traditional Chinese Medicine), winter is kidney season, and February is when their influence can be felt most strongly.

Let’s explore why – and what we can do to support our horses, especially our seniors, as we pass through winter’s deepest point.

Why winter belongs to the kidneys

In Traditional Chinese Medicine, winter is associated with the water element - stillness, storage, and the deep reserves of energy the body relies upon for strength and resilience. The kidneys sit at the centre of this system and are considered the body’s “battery pack” – the seat of regulation, warmth, hydration and constitutional strength.

Interestingly, while this framework comes from ancient medicine, modern physiology agrees with much of the underlying concept.

The kidneys regulate:

• hydration
• electrolyte balance
• circulation and blood pressure
• temperature regulation
• filtration of metabolic waste
• elements of hormonal balance through adrenal connection

In short? The kidneys are master regulators, and winter challenges every one of these jobs. Cold weather contracts tissues, slows circulation, encourages dehydration, and affects how the body uses energy. And our more senior horses – whose regulatory systems naturally work harder – often feel this most strongly.

How winter shows up in our senior horses

If you’ve ever watched a senior horse step out of the stable on a frosty morning, moving a shade more slowly or carefully, you’ve seen the impact winter can have on the deeper regulatory systems of the body.

Common winter signs include:

• feeling the cold more intensely
• stiffer backs and joints
• a visible dip in energy
• drinking less when it’s really cold
• difficulty maintaining condition
• appearing more fragile or “older” on icy, damp days

None of these are signs of a kidney problem in the diagnostic sense. Instead, they're reminders that the internal systems responsible for warmth, hydration, circulation and energy are working harder in the deep cold of February.

Understanding Yin and Yang (in simple, horse-owner language)

In TCM, every organ has both a Yin and a Yang aspect:

• Kidney Yin relates to moisture, nourishment, cooling, and the deep reserves of strength.
• Kidney Yang relates to warmth, spark, movement and energy.

Older horses – or horses under stress, or dealing with long-term wear and tear – often slide toward depleted Yin first. In practical terms, that can look like dryness, tension, irritability, or losing condition.

Over time, as Yin runs low, Yang follows – which is when older horses start to feel colder, stiffer, and more fatigued.

If you’ve ever watched a senior horse on a frosty morning move more slowly than usual… that’s the picture.

What we can do in February

The good news is that we can make a meaningful difference during kidney season. It's not so much about "treating" an organ as more about understanding what the body asks for in winter.

• Encourage hydration with warm water
• Always ad-lib forage
• Keep them warm (but always avoid over-rugging)
• Consider naturally warming herbs where appropriate
• Give seniors extra time to move and loosen up
• Create soft, warm resting areas to protect joints

Nothing complicated – simply supporting the systems that regulate everything behind the scenes.

Looking toward early spring

As February passes, the body begins shifting toward spring’s metabolic demands:

• coat changes
• hormonal activity
• gut flora shifts
• energy and behaviour changes
• grass transition

Supporting the kidneys during winter’s end helps set the body up for a smoother transition into this dynamic season.

A nod to Dr Tom Schell, D.V.M, CVCH, CHN

This reflection was inspired by a recent article from U.S. holistic veterinarian Dr Tom Schell, whose blend of functional physiology and traditional insight aligns closely with my own EquiNatural ethos. He frequently invites readers to pause, question and look beneath the surface – and winter kidney function is a perfect example of that deeper view.

Supporting the liver:kidneys:lymph pathway

At EquiNatural, our LKLCARE blend is designed especially for the liver–kidneys–lymph pathway, offering gentle support for steady filtration and whole-body balance. And for further liver/kidneys insights, see our Liver & Kidneys page in the Info Centre above - links below.