Healthy Hooves & Beyond

White Line Disease in Horses: Causes, Prevention, and Treatment

What is White Line Disease?

White Line Disease affects the stratum internum, a part of the hoof that connects the outer hoof wall to the sole. Despite its name, WLD does not directly affect the white line itself but instead weakens the inner hoof wall, leading to separation and structural compromise. This creates hollow spaces that allow further bacterial and fungal invasion.

 

Causes of White Line Disease

While the exact cause of WLD is not always clear, several factors contribute to its development:

  1. Hoof Wall Defects – Cracks, separations, or previous injuries to the hoof wall can allow bacteria and fungi to enter.

  2. Wet and Unsanitary Conditions – Excess moisture softens the hoof, making it more susceptible to infection, while dirty environments encourage microbial growth.

  3. Dry and Brittle Hooves – Conversely, excessively dry hooves may develop cracks and separations that create an entry point for pathogens.

  4. Poor Hoof Balance and Farrier Care – Long toes, flares, or neglected trims can create stress on the hoof, leading to separations where WLD can take hold.

  5. Compromised Hoof Integrity – Conditions such as laminitis or poor hoof quality due to nutritional deficiencies can make horses more prone to WLD.

  

Signs and Symptoms of White Line Disease

WLD can progress silently in its early stages, making regular hoof inspections crucial. Key signs include:

  • Chalky, crumbly, or powdery hoof wall material when cleaning or trimming the hooves.

  • Hoof wall separation or hollowed-out areas near the white line.

  • Black or gray discoloration within the affected area.

  • Increased hoof sensitivity in advanced cases, potentially leading to lameness.

  • A hollow sound when tapping on the hoof wall, indicating internal separation.

 

What is White Line Disease?

 

Diagnosing White Line Disease

A veterinarian or farrier can diagnose WLD through visual inspection and hoof testing. In some cases, radiographs (X-rays) may be used to assess the extent of hoof wall separation and rule out deeper structural involvement.

 

Prevention of White Line Disease

Preventing WLD requires a proactive approach to hoof health:

  1. Regular Farrier Care – Routine trimming every 4-6 weeks helps maintain hoof balance and prevents separations.

  2. Proper Stall and Pasture Management – Keep hooves clean and dry by maintaining clean bedding and avoiding prolonged exposure to mud or wet conditions.

  3. Balanced Nutrition – Ensure your horse’s diet includes biotin, zinc, copper, and amino acids to support strong hoof growth.

  4. Hoof Cleaning and Inspection – Pick out hooves daily and inspect for any early signs of cracking or separation.

  5. Protective Hoof Care – In horses with chronic hoof issues, topical hoof conditioners or sealants can help maintain moisture balance and strengthen the hoof wall.

 

Treatment of White Line Disease

If WLD is detected, prompt treatment is necessary to stop the progression and allow healthy hoof regrowth. Treatment steps include:

  1. Trimming and Resection – A farrier or veterinarian will remove all infected, separated hoof wall material to expose healthy tissue and prevent further microbial growth.

  2. Antimicrobial Treatment – Medicated hoof soaks, iodine-based solutions, or commercial antifungal and antibacterial treatments (such as White Lightning or CleanTrax) can be applied to kill bacteria and fungi.

  3. Hoof Protection – In severe cases, hoof boots or supportive shoeing may be used to stabilize the hoof while new, healthy growth occurs.

  4. Environmental Management – Ensure the horse’s environment is kept dry and clean to prevent reinfection.

  5. Ongoing Monitoring – Regular follow-ups with a veterinarian or farrier are essential to track healing progress and prevent recurrence.

 

Conclusion

White Line Disease is a serious hoof condition that requires diligent management. With proper hoof care, a clean environment, and early intervention, horses can recover fully. Regular inspections and prompt treatment will help ensure your horse remains sound and free from this destructive hoof infection.

If you suspect White Line Disease in your horse, consult your veterinarian and farrier immediately for the best course of action.