This year we have seen a rise in reported sun and sweat-related skin issues in horses. The sun can have both positive and negative effects on horses, depending on factors like exposure duration, intensity and the individual horse's health. In this blog, we highlight the positive and negative effects of the sun, and how best to manage the negative effects.
Let's first start with the positive effects the sun has on horses:
1. Vitamin D synthesis and bone health
Exposure to sunlight helps horses produce vitamin D, which is crucial for calcium absorption and bone health. Adequate vitamin D levels support the development and maintenance of strong bones.
2. Mood and well-being
Horses benefit from being outside in natural light, as it aligns with their natural behaviours. Just like humans, sunlight can positively affect horses' mood, reducing stress and promoting overall well-being.
3. Regulation of circadian rhythms
Exposure to natural daylight helps regulate a horse's circadian rhythms, ensuring better sleep patterns and overall health.
So far so good, but there are also negative sun-related effects to be aware of:
1. Sunburn- Horses with light-coloured skin, especially around the nose, muzzle, and eyes, can be prone to sunburn. Prolonged exposure to intense sunlight can cause painful burns and skin damage.
- Prevention: Applying sunscreen designed for horses, such as Sweet Sun Relief cream, or simply providing shade can help protect them from sunburn.
2. Overheating
- Excessive sun exposure, particularly in hot weather, can lead to dehydration, heat stress, or even heatstroke in horses. Symptoms include excessive sweating, lethargy, rapid breathing, and elevated heart rate.
- Prevention: Ensuring access to fresh water, shade, and sometimes electrolytes can help prevent these conditions.
- Some horses may develop photosensitivity, where their skin becomes overly sensitive to sunlight. This can cause severe reactions, such as blistering and swelling, particularly if the horse consumes certain plants or medications that trigger this condition.
- Prevention: Provide adequate field shade or turn out at night during summer months.
- Prolonged exposure to UV rays can cause damage to a horse's eyes, leading to conditions like equine recurrent uveitis (moon blindness) or cataracts.
- Prevention: Using fly masks with UV protection or providing access to shaded areas can help mitigate this risk.
- Dark-coloured horses, particularly those with black or bay coats, may experience sun bleaching, where their coat colour fades or turns reddish-brown with prolonged sun exposure. While this is mostly a cosmetic issue, it can be a sign of excessive sun exposure.
- Prevention: Provide adequate field shade or turn out at night during summer months.
Warm weather, exercise and the use of fly sheets, and fly masks can also lead to excessive sweating. When a horse sweats heavily, the sweat can accumulate on the skin, especially in areas where the skin folds or where tack (such as saddles and girths) has contact with the skin. As sweat evaporates, it leaves behind salts and minerals that can irritate the skin, leading to discomfort and inflammation.
This can cause sweat irritation, also known as 'sweat rash' or 'sweat scald'.
Sweat can also make the skin more prone to friction, especially under tack. The
combination of sweat, friction, and movement during exercise can exacerbate irritation in areas like the girth, under the saddle, or between the hind legs.
Sweat creates a moist environment that can promote the growth of bacteria or fungi, leading to infections like rain rot or fungal dermatitis if not properly managed.
The symptoms of sweat irritation are likely to be:
- Redness and inflammation
- Itching and discomfort
- Scabs and sores: If the irritation is severe, scabs, sores, or even hair loss may develop.
- Sensitive skin: the skin may become more sensitive to touch, making the horse resistant to being tacked up or groomed.
Prevention:
- Regular grooming and the use of an astringent cleanser (such as Sweatbuster) will help remove sweat and dirt from the coat, reducing the risk of irritation. Pay special attention to areas prone to sweating, like the girth, under the saddle, and between the hind legs.
- Post-exercise care: allow the horse to cool down properly. Walk the horse to help dissipate heat and reduce sweating. Thoroughly rinse the horse with water to remove sweat and salts from the coat. Consider applying a drying powder such as Flowers & Zinc to help absorb any excess moisture. Ensure the horse is dried off properly, especially in humid conditions and if using a rug.
- Sweat-absorbing products: Choose saddle pads that wick away moisture and keep the skin dry. Ensure they are clean and dry before each use, using gentle non-bio laundry products.
- Providing electrolytes can help replace salts lost through sweating and support overall hydration, reducing excessive sweating.
Managing sweat rash:
- Only wash with very mild cleansers that are appropriate for equine skin. Harsh medicated shampoos can often make things worse.
- Dry thoroughly with cotton wool, then apply a drying powder followed by soothing topical products - such as those which contain Silver, to target areas.
- Vet consultation: If the irritation is severe or doesn’t improve with basic care, consult a veterinarian for advice and possible treatment.
Summary:
Sunlight has both positive and negative effects on horses. On the positive side, it aids in vitamin D synthesis, supports bone health, improves mood and well-being by promoting natural behaviours, and helps regulate circadian rhythms for better sleep. However, excessive sun exposure can lead to negative effects such as sunburn, dehydration, heat stress, photosensitivity, eye damage, and fading coat colours. Additionally, warm weather and exercise can cause excessive sweating, leading to skin irritation and infections. To manage these risks, it is important to provide shade, apply sunscreen, ensure proper hydration, use appropriate grooming products, and monitor tack fit. Regular grooming and post-exercise care are also essential in preventing and managing sweat-related skin issues.