Scratches / Mud Fever

Scratches, also known as mud fever, is a common inflammatory skin condition affecting horses’ legs and lower limbs. This fungal and bacterial infection thrives in wet, muddy, and unsanitary conditions, making it a frequent concern for horse owners in areas with poor drainage or high moisture. The condition can progress rapidly if left untreated, potentially causing severe pain, lameness, and permanent skin damage. Understanding the causes, recognizing early signs, and implementing proper management strategies are essential for protecting your horse’s health and mobility.

While scratches is rarely life-threatening, it can significantly impact your horse’s quality of life and performance. The condition requires consistent treatment and environmental management to resolve, with recovery timelines typically ranging from 2 to 8 weeks depending on severity. This article provides horse owners and caretakers with evidence-based information on identifying, treating, and preventing scratches to keep your equine partner healthy and sound. Always consult an equine veterinarian for diagnosis and treatment recommendations, as this article is not a substitute for professional veterinary care.

Understanding Scratches and Mud Fever

Scratches is a non-contagious dermatitis that develops when bacteria and fungi colonize the skin on a horse’s lower legs, particularly in the heels, fetlock area, and pastern. The condition is called “scratches” in North America and “mud fever” in the United Kingdom and other regions, though both terms describe the same disease process. The infection typically occurs in one or more legs, with hind legs being more frequently affected than front legs due to their exposure to mud and moisture when grazing or standing in wet conditions.

The pathogenic organisms responsible for scratches include secondary bacterial invaders such as Staphylococcus and Streptococcus species, combined with fungal elements like dermatophytes or opportunistic fungi. The condition develops when protective skin barriers are compromised by prolonged moisture exposure, causing the epidermis to soften and become vulnerable to microbial invasion. This creates an inflammatory response that manifests as crusting, scabbing, swelling, and pain. The severity of scratches can range from mild surface inflammation to severe, deep tissue infection that may require aggressive medical intervention.

Draft horses with heavy feathering face elevated scratches risk not only because of moisture retention but because many draft breeds carry coat-texture traits selected over centuries for cold-climate work. Understanding a draft breed’s baseline physiology can inform prevention planning; the Estonian Draft — a cold-blooded breed known for dense feathering — is profiled at Horse-Info: Estonian Draft horse breed as a representative example of the feathered-leg conformation type.

Causes and Risk Factors

The primary cause of scratches is exposure to wet, muddy environments combined with poor hygiene and compromised skin integrity. Horses standing in muddy paddocks, wet pastures, or unsanitary stalls are at significantly higher risk of developing the condition. Additional risk factors include the following:

• Wet weather and seasonal moisture: Scratches incidence increases during rainy seasons and in regions with high humidity. Horses living in wet climates face year-round exposure risks.
• Poor pasture drainage: Low-lying areas of paddocks that collect standing water create ideal breeding grounds for mud fever-causing organisms.
• Inadequate hoof care: Overgrown hooves and poor hoof hygiene allow mud and moisture to accumulate, increasing infection risk.
• Leg clipping or trauma: Horses with clipped heels or recent skin injuries have compromised barriers that allow pathogenic entry.
• Skin sensitivity and allergies: Horses with dermatitis, eczema, or allergic reactions have naturally weakened skin defenses.
• Heavy feathering: Horses with heavily feathered legs (such as draft breeds) may retain moisture more readily in the fetlock and pastern region.
• Immunosuppression: Horses experiencing stress, illness, or compromised immune function are more susceptible to secondary infections.
• Poor stable management: Infrequent stall cleaning and wet bedding create persistent exposure to pathogens.

Recognition and Symptoms

Early Signs

Early detection of scratches allows for faster recovery and prevents progression to more severe forms. Initial signs typically appear 3 to 7 days after exposure to optimal conditions for the causative organisms. Watch for the following early indicators:

• Mild swelling in the fetlock or pastern region
• Slight redness or irritation in the skin creases
• Scabbing or crusting starting to form
• Subtle heat or warmth when palpating the affected leg
• Minor lameness or stiffness, particularly when first moving out
• Your horse may appear to be itching or uncomfortable when the area is touched

Advanced Symptoms

If scratches progresses without treatment, symptoms become increasingly severe and painful. Advanced presentations may include the following characteristics:

• Pronounced swelling, thickening, and edema extending up the leg
• Deep cracks and fissures in the skin with active bleeding
• Purulent discharge or drainage from infected skin areas
• Foul odor emanating from the lesions, indicating bacterial overgrowth
• Significant lameness or reluctance to bear weight on the affected limb
• Secondary cellulitis or lymphangitis affecting the entire lower leg
• Systemic signs such as fever, lethargy, or swollen lymph nodes in severe cases

Diagnosis and Professional Assessment

A veterinarian can typically diagnose scratches based on clinical appearance and history of exposure to wet or muddy conditions. Your veterinarian may perform the following assessments:

• Physical examination: Thorough inspection of affected areas, assessment of swelling, and evaluation of lesion characteristics
• Skin scraping or biopsy: Microscopic examination to identify specific fungal or bacterial organisms, though often unnecessary if clinical signs are clear
• Culture and sensitivity testing: Recommended in severe cases to identify antibiotic resistance patterns and guide antimicrobial therapy
• Differential diagnosis: Ruling out other conditions such as pastern dermatitis, photosensitivity reactions, or pemphigus foliaceus

Contact your equine veterinarian immediately if your horse develops severe lameness, signs of systemic infection (fever, lethargy), or if the condition fails to improve after 2 weeks of appropriate treatment. These signs may indicate secondary cellulitis or other complications requiring aggressive medical intervention.

Treatment Approaches

Cleaning and Hygiene Management

Proper wound cleaning is the foundation of scratches treatment. Daily cleansing removes debris, crusts, and pathogenic organisms, reducing infection severity and promoting healing. Follow these cleaning protocols:

1. Use warm water and a gentle antibacterial or medicated wash to cleanse affected areas
2. Gently remove dried crusts and scabs with a soft brush or cloth, taking care not to cause bleeding
3. Rinse thoroughly with clean water until all soap residue is removed
4. Pat the area dry completely with clean towels
5. Apply prescribed topical medications or treatments once the area is completely dry

Topical Medications

Veterinarians typically recommend one or more topical treatments depending on the severity and characteristics of the infection:

• Antimicrobial ointments: Antibiotic creams such as those containing neomycin or gentamicin help control bacterial secondary infection
• Antifungal agents: Topical antifungals such as ketoconazole or miconazole address fungal components of the infection
• Ichthammol or tar-based products: Drawing agents help reduce inflammation and promote drainage of infected material
• Zinc oxide or petroleum-based barriers: Protective ointments prevent moisture recontamination and protect newly healing skin
• Medicated poultices: These agents help reduce swelling and promote tissue healing, applied under wraps or bandages

Systemic Treatment

In moderate to severe cases, your veterinarian may recommend systemic medications to complement topical therapy:

• Oral antibiotics: May be prescribed if bacterial infection is severe or showing signs of cellulitis (typically 7 to 14 days of treatment)
• Antifungal medications: Oral or injectable antifungals such as griseofulvin in severe fungal-dominant infections
• Anti-inflammatory medications: Phenylbutazone (bute) or firocoxib may reduce pain and inflammation, improving your horse’s comfort and mobility
• Immune support: Vitamin and mineral supplementation supports skin healing and immune function during recovery

Bandaging and Leg Wrapping

Strategic bandaging protects healing tissue and maintains topical medications in contact with affected skin. Proper wrapping also provides support and helps control swelling. Bandages should be changed daily during active treatment phases, with careful attention to maintaining proper tension (snug but not so tight as to impair circulation). Your veterinarian or experienced equine handler can demonstrate appropriate wrapping techniques to prevent pressure necrosis and complications.

Prevention Strategies

Prevention Strategy	Implementation	Effectiveness Timeline
Improve pasture drainage	Fill low areas, add gravel, install drainage systems	Permanent after installation
Increase turnout area maintenance	Remove standing water, rake paddocks weekly, add dry bedding	Immediate improvements
Regular hoof trimming	Trim every 6-8 weeks; keep heels properly balanced	Ongoing prevention
Daily leg inspection and cleaning	Check all four legs daily; wash off mud within 24 hours	Daily protection
Apply preventive barrier creams	Use lanolin or protective ointments during wet seasons	Seasonal application
Maintain dry bedding	Change stall bedding daily; use absorbent materials like shavings	Ongoing prevention
Limit exposure to mud	Provide run-in sheds; avoid muddy areas during turnout	Seasonal adjustments

Recovery Timeline and Prognosis

Recovery from scratches typically progresses through distinct phases. Mild cases may resolve within 2 to 3 weeks with appropriate treatment and environmental management. Moderate infections usually require 4 to 6 weeks of consistent care, while severe cases may take 8 weeks or longer to fully resolve. Some horses with severe or recurrent scratches may develop chronic thickening and permanent textural changes in the affected skin, though functional recovery is usually complete.

Prognosis is generally excellent when treatment is initiated early and environmental factors are addressed. Horses that continue to be exposed to muddy, wet conditions or receive inconsistent treatment experience prolonged recovery periods and higher recurrence rates. Once healed, your horse should return to normal function and performance capability, though ongoing preventive measures remain essential to avoid reinfection.

Frequently Asked Questions

Is scratches contagious between horses?

Scratches is not contagious from horse to horse. The condition develops when an individual horse’s skin is compromised by environmental factors and exposure to pathogenic organisms in mud and wet environments. However, horses sharing the same wet pastures or muddy areas have similar exposure risks, which may make it appear that the condition spreads. Maintain good hygiene practices and separate care equipment (brushes, towels) to prevent cross-contamination of minor skin abrasions.

Can scratches be prevented entirely?

Complete prevention is not always possible, particularly in regions with high moisture and rainfall. However, the incidence and severity of scratches can be significantly reduced through excellent pasture management, prompt removal of mud and moisture from your horse’s legs, regular hoof care, and preventive barrier ointments during high-risk seasons. Horses with heavy feathering or those genetically predisposed to skin sensitivities may require more aggressive preventive measures than average horses.

What is the difference between scratches and pastern dermatitis?

Pastern dermatitis and scratches are often used interchangeably, though some clinicians distinguish pastern dermatitis as a purely bacterial infection while scratches incorporates both fungal and bacterial components. Both conditions present similarly with crusting, swelling, and inflammation in the pastern region. Treatment approaches are comparable, and your veterinarian will determine the primary pathogenic component through examination and testing if necessary. Management and prevention strategies remain the same for both conditions.

Should I clip my horse’s heels to treat scratches?

Clipping heels may be beneficial for horses with heavily feathered legs, as it reduces moisture retention and improves visibility of affected areas for treatment. However, clipping itself can create minor skin trauma that increases infection risk if proper hygiene is not maintained. If clipping is performed, do so carefully, keep the clipped area absolutely clean and dry, and apply protective ointments immediately after clipping. Discuss the pros and cons with your veterinarian for your specific horse’s circumstances.

Key Takeaways

• Scratches (mud fever) is a bacterial and fungal skin infection affecting the lower legs and pastern region, caused by prolonged exposure to wet, muddy environments.
• Early signs include mild swelling, crusting, and slight lameness; untreated cases progress to deep tissue involvement, severe pain, and potential complications like cellulitis.
• Treatment combines daily cleaning, topical antimicrobial and antifungal medications, bandaging, and in severe cases, systemic antibiotics and anti-inflammatory medications.
• Recovery typically requires 2 to 8 weeks of consistent care, with prognosis excellent when environmental factors are addressed and treatment is initiated early.
• Prevention focuses on drainage improvement, regular hoof care, daily leg cleaning, dry stall management, and protective barrier ointments during high-risk wet seasons.
• Consult an equine veterinarian for diagnosis, treatment recommendations, and guidance on environmental modifications specific to your horse and facility.
• Contact your veterinarian immediately if your horse develops severe lameness, signs of systemic infection, or if symptoms do not improve within 2 weeks of appropriate treatment.