Here comes the SUN

Amy Hayek
2 days ago
3 min read

☀️ Let the Sunshine In: Why Your Horse Needs Daily Time Outdoors

In the age of performance barns, climate-controlled stalls, and pristine indoor arenas, it’s easy to forget that horses were born to live outside. While we’ve gotten better at managing their nutrition, training, and comfort, there’s one critical factor often overlooked in modern horse care: sunshine.

Yes, actual sunshine.

Your horse doesn’t just enjoy the sun—it needs it. And here's why:

🌞 Vitamin D: The Sunshine Vitamin

Vitamin D is essential for bone strength, immune health, and overall metabolic balance. While horses can get small amounts through diet, the most natural and effective source is direct sunlight.

When ultraviolet B (UVB) rays hit the horse’s skin, the body begins the process of making vitamin D. Horses kept mostly indoors, or under blankets and hoods, often don’t get enough. And contrary to popular belief, sunlight through a window won’t do the trick—glass blocks the UVB rays needed for this process.

Horses with insufficient vitamin D may experience:

Poor coat quality
Slower recovery from injury
Decreased immune resilience
Muscle weakness and even bone softening in extreme cases

🧠 Mood, Behavior & Nervous System Support

Sunlight helps regulate a horse’s circadian rhythm, which governs sleep, hormone production, and behavior. Horses with regular outdoor access often show calmer, more stable dispositions. They’re more likely to rest naturally, nap in the sun, and demonstrate relaxed, content body language.

If your horse seems stressed or dull indoors but brightens up with pasture time, sunshine may be part of the reason why.

🐎 Movement, Digestion & Hoof Health

Most horses who get sunshine also get to move. Grazing, walking, rolling, and interacting with herdmates all promote:

Healthy digestion
Proper hoof and joint function
Mental stimulation and emotional balance

Sunshine is part of a whole-horse health plan, not just a luxury.

🔥 But What About Sunburn?

Here’s where things get interesting: sunburn isn’t always just about the sun.

Many horses who burn easily—especially on white faces or socks—are not reacting to sunlight alone, but to how their body is handling it. The liver plays a key role in managing photoreactive compounds in the skin. When the liver is under stress, these compounds build up, and the skin becomes more sensitive to UV damage.

What stresses the liver? Alfalfa and clover are common culprits.

These lush, protein-rich plants often contain photosensitizing compounds that—when not properly filtered by the liver—can lead to skin inflammation and sunburn-like reactions. If your horse is burning despite reasonable sun exposure, take a look at the pasture and the hay. A diet heavy in alfalfa or clover may be the underlying issue, not the sunshine itself.

🧠 Pro tip: Chronic sunburn in horses—especially those with pink skin—should prompt a nutritional and liver function review, not just a fly mask solution.

🌿 Practical Tips for Healthy Sun Exposure

Aim for several hours of turnout daily, especially during early morning or late afternoon when UV rays are gentler.
Offer both sun and shade so the horse can self-regulate.
Rotate grazing areas to avoid overexposure and maintain healthy pasture.
Limit alfalfa and clover if your horse is showing signs of sun sensitivity.
Use masks and shade, but don’t assume they solve the root problem.

In Short: Sunlight is essential to your horse’s health—but like everything else in horsemanship, context matters. Let the horse be a horse: give it space, movement, light, and the right forage. That’s the foundation of wellness—no supplement required.