Horse Skin Infections: Natural Remedies for Rain Rot & Fungus

Skin infections in horses—particularly those caused by fungi and bacteria are a frequent challenge, especially in warm, humid conditions. These infections are more than just cosmetic. These skin conditions can be itchy, painful and irritating. In some cases we can see these simple infections worsen.

This blog post outlines the causes, symptoms, and natural management for fungal infections and rain rot.

Rainrot doesnt always occur due to the rain. Sweating under a rug, or under a saddle pad can also create the environment for this skin infection to occur.

Common Equine Skin Infections: Fungal and Rain Rot

1. Dermatophytosis

Dermatophytosis is just a fancy name for ringworm

A contagious fungal infection caused by Trichophyton or Microsporum spp. It will show up as circular patches of hair loss with crusty edges, which can increase in size. Ringworm is not actually a worm, contrary to its name. Can spread via tack or grooming equiptment, or directly from one horse to another. This can also be contagious to you! This makes it a zoonotic disease, which just means its transmissible from your horse to you.

• Looks like Round, hairless, scaly or crusty lesions; mildly itchy.

  
  

2. Malassezia Dermatitis

Malassezia is a yeast-based skin condition often occurs in oily skin areas and may be linked to overgrooming, topical product overuse or inadequate rinsing off of a product such as shampoo, or poor skin microbiome balance- which occurs due to all the above.

• Looks like Greasy, flaky skin; odour; thickened skin folds.

  
  

3. Candidiasis

Less common, but may occur after antibiotic overuse or in immune-compromised horses. If your horse is showing symptoms of candidiasis, we have more to worry about than the skin alone.

• Looks like Patchy inflammation in mucosal areas or skin folds. This is a rare skin condition.

4. Rain Rot (Dermatophilosis)

Often mistaken for a fungal infection, rain rot is actually bacterial, caused by Dermatophilus congolensis. It thrives in wet, humid conditions and causes scabby, painful lesions along the back, rump, or legs.

• Looks like small raised bumps that scab. Hair comes off in "paintbrush like clumps with scabs. can be painful to touch

Rain rot is bacterial, but natural antifungal strategies often overlap due to their antimicrobial, drying, and immune-supportive properties.

What Causes These Skin Infections in Horses?

Cause	Explanation
Excessive moisture	Prolonged wet skin breaks down the skin barrier—ideal for fungi and bacteria such as Dermatophilus. This can be under a rug, in the rain or even under tack.
Poor grooming practices	Dirt, sweat, or matted hair can trap moisture and harbor microbes.
Compromised immunity	Stress, illness, or poor nutrition weakens skin defenses.
Shared gear and grooming tools	Contaminated equipment spreads fungi and bacteria.
Overuse of synthetic products	Harsh chemicals can damage skin microbiota and cause imbalance. This can weaken the natural skin defences

Natural Treatments and Holistic Approaches

Topical Remedies

Apple Cider Vinegar

Antimicrobial, dries skin, balances pH

Dilute 1:1 with water and spray on affected areas 1–2x/day

Calendula, chamomile and green tea

Anti-inflammatory, promotes healing, antimicrobial and antifungal.

This can be made up as a strong tea and applied directly to the areas of skin which are affected.

This can leave the skin wet, so only use when they are able to dry.

Use as spray or compress

Neem Oil

Antimicrobial, skin-soothing

Mix with carrier oil or add to natural shampoo

Colloidal silver

Antimicrobial and helps to disrupt the biofilm.

Apply with a spray or dab on.

For rain rot, some owners like to gently soften and remove scabs before applying treatments to avoid trapping moisture under crusts. However this can be painful. I have found applying topically over the scabs, and getting the product in under the scabs to be just as effective, then removing the scabs as they come away naturally.

Always Patch test topical products first.

Internal Support

Support your horse's immune system and skin barrier from the inside out. Most of these nutrients are required in a balanced diet. If you are wondering if your horse is not getting sufficient minerals, a diet assessment can be a valuable step in their care.

Nutrient/Herb	Function
Zinc + Copper	Crucial for skin healing and barrier integrity
Omega-3s (chia, linseed oil, hemp oil)	Anti-inflammatory, moisturizes from within
Vitamin E & Selenium	Boost tissue repair and immune defense
Medicinal Mushrooms	Support immune modulation (Reishi, Cordyceps)
Echinacea, Astragalus	Herbal immunotonics for chronic or recurrent issues

Hygiene & Environmental Management

• Dry the horse thoroughly after rain or hosing.

• Clean and disinfect tack, rugs, brushes, and wash them frequently.

• Use breathable natural fibre rugs instead of synthetics.

• regularly brush down. This is a bonding experience, and will also help to improve circulation to the skin.

For rain rot, avoid rugging wet horses and allow plenty of time for sun exposure and drying of the coat.

Using a cotton rug under a rainsheet can help to soak up and moisture, keeping the skin dry.

Skin conditions can even occur under rugs in cold weather if they get hot and sweaty

Skin infections in horses can progress if not address adequately

Most skin infections in horses are straight forward and many will resove on their own without much intervention.

Some horses, especially those with compromised immune function, or in a prolonged weather event can be more likely to have their simple skin condition progress into something more serious. Once we have a weakened area of skin, the protective barriers are compromised and the infection is able to penetrate deeper, or we have other opportunisitc secondary infections occuring.

A serious complication is cellulitis, where we have the infection penetrate into the deeper layers of the skin. This is a medical emergency, and prompt action is required.

When to call for professional support?

While mild infections can often be managed naturally, additional support may be needed if you notice any of the following signs or symptoms.

• Lesions spread rapidly or become painful

• Secondary infections occur (pus, heat, swelling). Cellulitis is a real complication risk in skin conditions.

• The horse shows systemic symptoms (fever, lethargy)

• The condition doesn’t improve within 10 days

A skin scraping or culture from the vet may help determine whether you’re dealing with fungal, bacterial, or mixed infections.

Working with an equine naturopath means you can get a personalised plan that supports your horse both inside and out—using quality herbs, supplements, and nutrition to help the healing process. And if the skin infection is more serious, your naturopath can easily team up with your vet to make sure your horse gets the best care possible

Skin infections in horses—whether fungal or bacterial like rain rot—are common but manageable with a whole-horse approach:

• Improve hygiene and reduce moisture

• Use natural topical agents safely and consistently

• Support skin and immune health with nutrition

• Observe for worsening or signs of deeper infection

  
  

Need Help?

At Vibrant Animal Health, we offer custom herbal blends and consults to support your horse’s skin from the inside out. Contact us to learn more about tailored equine care options for skin, gut, and immune balance.