Circular, bald patches in the coat that spread quickly – skin fungus is one of the most common and contagious skin diseases in horses. Fungal infections are particularly prevalent in the fall and winter months, when horses are kept closer together and their immune systems are weakened by coat changes and cold weather. In this guide, you will learn how to recognize skin fungus, how it is transmitted, how you can protect other horses and yourself, and which treatment methods are truly effective.

What is skin fungus and how does it develop in horses?

Skin fungus in horses is caused by various filamentous fungi (dermatophytes). The most common pathogens are Trichophyton equinum and Microsporum species. These fungi feed on keratin, the main component of skin, hair, and hooves.

How does a horse become infected with skin fungus?

The fungal spores are extremely resistant and can survive in the environment for months. Infection occurs through:

• Direct contact with infected horses—even brief sniffing can be enough 
• Shared equipment such as cleaning supplies, blankets, saddle girths, or halters 
• Contaminated stable equipment such as stall walls, fence posts, or drinking troughs 
• About humans as carriers – fungal spores adhere to clothing and hands 
• Through insects that can carry spores from horse to horse

Why are some horses more susceptible?

Weakened immune system due to stress, illness, or poor nutrition. Young horses and foals with immature immune systems. Coat change season, when the body is under additional strain. Warm, humid conditions in the stable. Poor hygiene and overcrowded stables.

Recognizing skin fungus: These symptoms are typical

A fungal infection in horses usually manifests itself with characteristic symptoms:

Early signs:

Small, circular bald patches in the coat, often with slightly raised edges. The skin underneath is scaly and sometimes slightly reddened. The patches often feel slightly crusty. Preferred locations are the head, neck, shoulders, and saddle area.

Advanced stage:

The bald patches become larger and spread. Several patches may merge. The fur around the affected areas breaks off easily. Sometimes there is mild itching, but not always. The skin may be scaly and crusty or weeping.

Important: Not every bald spot is a fungal infection! Other skin conditions such as eczema, mite infestation, or allergies can look similar. Find a clinic near you now.

Diagnosis: How the veterinarian diagnoses skin fungus

Even though the typical circular bald patches are very characteristic, the diagnosis should always be confirmed by a veterinarian:

Clinical examination:

Examination of the affected skin areas under good lighting conditions. Assessment of the location, shape, and spread of the skin changes. Examination of other horses in the herd.

Wood lamp (UV light):

Some types of fungi (especially Microsporum) glow green under UV light. This is a quick screening test, but not all fungi glow, so a negative result does not rule out infection.

Skin scrapings and microscopic examination:

A scalpel is used to remove skin flakes and hairs from the affected areas. Fungal spores and infected hairs can be seen under the microscope. By examining a skin scraping in the laboratory, various other skin diseases can be diagnosed or ruled out in addition to skin fungus.

Mushroom culture (gold standard):

The sample is cultivated on a special culture medium. After 1 to 3 weeks, the exact pathogen can be identified. This is the most reliable method, but it takes longer.

Do you suspect your horse has a fungal skin infection? The specialists at Altano clinics will carry out a reliable diagnosis and initiate the correct treatment. Find a clinic near you now.

Risk of infection: How can you protect other horses?

Skin fungus is highly contagious! As soon as you suspect you have it, you must act immediately to prevent it from spreading:

Immediate measures in the barn:

Immediately isolate the affected horse in a separate stall. Clearly mark the stall (e.g., with a red sign saying "Skin fungus – caution!"). Only use your own grooming equipment, blankets, and equipment for this horse. Always treat the infected horse last in the stable. Change your clothes and wash your hands thoroughly after contact with the horse. If several horses in the stable have skin fungus, they should still be isolated from each other.

Hygiene measures for all other horses:

Check all other horses daily for suspicious skin areas. Do not share grooming equipment between different horses. Disinfect stall walls, water troughs, and feed troughs regularly. Clean saddle girths, halters, and other equipment thoroughly.

Disinfection of contaminated objects:

Blankets, saddle pads, and halters must be washed at a minimum temperature of 60 degrees Celsius. Cleaning equipment should be soaked in hot water with a fungicidal disinfectant. Wipe hard surfaces with fungicidal disinfectants (e.g., based on sodium hypochlorite or enilconazole). Brushes can also be placed in the freezer for 24 hours—cold temperatures kill many spores.

Treatment of skin fungus in horses

Treatment requires patience and consistency. Depending on the extent of the infestation, various methods are used:

Local treatment:

Local treatment is the most important measure. In most cases, consistent external treatment is completely sufficient. Wash the horse with antifungal solutions (e.g., enilconazole, brand name Imaverol). The entire horse should be washed, not just the affected areas. The fungal spores can be distributed throughout the coat and are not visible to the naked eye. Washing should be carried out every 3-4 days, for a total of 3-4 applications. If possible, the solution should not be rinsed off, but allowed to dry on the horse. If necessary, long hair around the lesion can be carefully trimmed with scissors. Crusts should only be removed after soaking. Disposable gloves must be worn throughout the entire procedure. Antifungal ointments or sprays can also be applied to the bald areas. The antifungal solutions, shampoos, ointments, and sprays are only available from pharmacies and are not freely available for sale, so they are usually obtained from a veterinarian. 

Systemic treatment:

In rare, very severe cases, treatment with antifungal medication in the form of tablets or injections (e.g., itraconazole) may be necessary.  The decisive factor in choosing the therapy is the degree of suffering of the horse, for example, whether severe itching occurs. In most cases, skin fungus in horses is not very painful. Systemic therapy is only indicated in cases of very severe, generalized infestation or failure of local treatment.

Important: Do not stop treatment prematurely, even if the symptoms have disappeared! The fungal spores can survive for weeks. Continue treatment consistently until your veterinarian has performed a follow-up examination.

Does your horse need effective treatment for skin fungus? The experts at Altano Group will advise you on the best therapy. Get in touch now.

When is vaccination advisable?

In some countries, vaccines against skin fungus (especially against Trichophyton equinum) are available. These can be used both preventively and therapeutically. A fungal vaccination does not replace local treatment, but can be used as an additional measure.

Benefits of vaccination:

• Can accelerate healing in cases of existing infection. 
• Protects other horses in the herd. 
• Particularly useful for larger inventories or recurring problems.

Disadvantages:

• Not available in all countries. 
• Does not provide 100 percent protection; effectiveness varies from person to person. May cause local reactions at the injection site.

Talk to your veterinarian about whether vaccination is advisable in your case.

Environmental disinfection: the often forgotten step

Treating the horse alone is not enough—the environment must be thoroughly cleaned, otherwise relapses may occur. It is also important to clean all areas thoroughly before disinfecting, as contaminants cannot be disinfected.

Box and stable area:

First, remove the bedding. Wash the walls, floors, grids, and drinking troughs with hot water and detergent. Disinfect all surfaces with a fungicidal disinfectant. Allow the box to dry thoroughly and air out before adding new bedding. Repeat the disinfection after 2 weeks.

Pasture shelters and paddocks:

Here too, fence posts, shelter walls, and drinking troughs should be disinfected. Remove all old bedding completely.

Cleaning area and washing area:

These areas are particularly at risk, as many horses are groomed and washed here. Thorough cleaning and disinfection is essential.

Risk of infection for humans: How to protect yourself

Skin fungus in horses is a zoonosis, meaning it is a disease that can be transmitted to humans! Humans can quickly become infected and develop circular, itchy, scaly skin lesions.

Protective measures for horse owners and stable staff:

• Always wear gloves when handling infected horses.
• Wash your hands thoroughly with soap after each contact.
• Wear long-sleeved clothing when washing the horse and change it afterwards.
• Avoid direct skin contact with the affected areas.
• Wash the clothes immediately at a minimum temperature of 60 degrees Celsius.

Persons at particular risk:

Children often have closer physical contact with horses – pay particular attention to hygiene. People with weakened immune systems should avoid contact with infected horses. If you suspect you may be infected, consult a dermatologist!

Do you have questions about hygiene in the barn or infection control? The veterinarians at Altano Group can provide you with comprehensive advice. Arrange a consultation.

Prevention: How to reduce the risk of skin fungus

Even though not every infection can be prevented, you can significantly reduce the risk:

Optimizing stable hygiene:

Regular cleaning and disinfection of stalls, grooming areas, and equipment. Each horse should have its own grooming kit—no sharing! Blankets, halters, and saddle pads should be washed regularly. Good ventilation in the stable and dry stalls are also important—fungi thrive in warm, humid conditions. 

Would you like a comprehensive prevention concept for your barn? The experts at the Altano Group can help you with barn hygiene and prevention. Arrange a consultation.

Strengthen your immune system:

Ensure that your animals are fed a diet that meets their needs and contains sufficient vitamins and trace elements. Zinc and biotin are particularly important for healthy skin. Stress reduction is also an important supportive measure—make sure that the herd composition is compatible and that there is sufficient space. Regular exercise and fresh air strengthen the immune system.

Be cautious with new additions:

New horses should initially be isolated and thoroughly examined for skin changes. Only after a quarantine period of at least 2 weeks should they be allowed to join other horses. This quarantine period is also crucial for other infectious diseases. 

For tournaments and training courses:

Always bring your own cleaning supplies. Do not let your horse drink from unfamiliar water buckets. Wash all equipment thoroughly after returning home.

Healing process: What can you expect?

With consistent treatment, skin fungus usually heals completely:

Typical course:

Weeks 1 to 2: The bald spots will not get smaller at first, and may even temporarily get larger. This is normal—the treatment takes time. Clinical improvement should occur after 1-2 weeks.  

Weeks 3 to 4: First regrowth of fur at the edges of the bald spots. The skin becomes smoother and less flaky. 

Weeks 5 to 8: Continued hair growth. The bald spots become smaller. Weeks 8 to 12: In most cases, the hair has completely grown back.

Important: The regrowing fur may initially be a different color (lighter or darker) or have a different texture. This usually normalizes over time.

Monitoring treatment success:

After 4 weeks of treatment, a follow-up examination should be carried out by the veterinarian. A final fungal culture can ensure that the infection has been completely eliminated. Quarantine should only be lifted once the veterinarian has given the green light.

Does your horse need effective treatment for skin fungus? The experts at the Altano Group will advise you on the best therapy. Get in touch now.

Conclusion: Consistency is the key to success

Skin fungus in horses is persistent, but with the right treatment and, above all, consistent hygiene, it can be brought under control. Recognize skin fungus early on by looking for circular bald patches and have the diagnosis confirmed by a veterinarian. Isolate affected horses immediately to prevent the spread of infection. Treat consistently for at least 4 weeks, even if the symptoms disappear earlier. Disinfect the entire environment thoroughly, otherwise there is a risk of recurrence. Protect yourself through hygiene measures – skin fungus is transmissible to humans.

With patience, consistency, and the right treatment, your horse will get rid of the skin fungus and will soon be able to rejoin the herd, fully recovered.

For better readability, we predominantly use the generic masculine in our texts. It goes without saying that all personal designations refer equally to all genders. The abbreviated form of language is used solely to improve comprehensibility and is to be understood in an unbiased manner.