What Is White Line Disease in Horses and How to Treat It?

If you’ve ever had a horse with hoof problems, then you know the truth in the saying, “No hoof, no horse.” White Line Disease—also called hollow foot, stall rot, wall thrush, or seedy toe—is a hoof problem every horse owner wants to avoid. 


The white line is the narrow, light-colored band on the underside of a freshly trimmed horse hoof between the hoof wall and where it meets the sole. When this area becomes damaged, infection can set in, causing separation of the layers of the hoof wall. 

What Is White Line Disease?

Despite the name of the disease, the white line isn’t actually affected, although the effects can first be seen in the white line area. The condition happens when fungus and/or bacteria invade the hoof and start separating the hoof wall. The infection can then spread around the hoof and up the inside of the wall. 

What Causes White Line Disease in Horses?

White Line Disease has been around for a long time, yet we still don’t fully understand its causes. Experts are divided on whether it’s caused by a fungus or bacteria—or a combination of both. Some postulate that stress, like faulty hoof conformation, flexor deformities, wear from hard ground, overly long toes, etc. can cause the laminae to tear and bleed, which provides optimum conditions for soil-dwelling bacteria or fungi to enter the hoof. It does appear that White Line Disease is opportunistic, so it will take advantage of a weakened or compromised hoof wall.


Other factors that may be connected are:


  • Lack of exercise
  • Shoes that are too small
  • Wet conditions in pastures or stalls
  • Inadequate nutrition
  • Poor stable hygiene

What Does White Line Disease Look Like in Horses?

White Line Disease is usually first noticed during a routine trimming. A veterinarian or farrier may note these symptoms:


  • Separation of the hoof wall
  • Slowed growth of the hoof wall
  • Crumbly or powdery white or gray tissue at the white line
  • A hollow sound when tapping at the outside wall of the affected area
  • Bulges or sunken areas of the hoof
  • Warmth in the foot
  • Pain
  • Lameness (severe cases)

Is White Line Disease Contagious?

White Line Disease is not contagious. A horse can only have it in one hoof, and a farm can only have the disease present in one horse and not the others.

Can White Line Disease Cause Lameness?

No horse owner wants their horse to be lame, but in severe cases, White Line Disease can cause lameness. Make sure your horse is regularly visiting the vet or farrier to catch White Line Disease early. 

How Do You Treat White Line Disease in Horses?

It’s important to consult both a veterinarian and a farrier to effectively treat White Line Disease. Treatment usually involves four steps.

Step 1: Remove Infected Tissue

You will first want to eliminate every bit of infection. In most instances, scraping out the infected tissue in the hollow area with a hoof knife will suffice. But in more advanced cases, your vet or farrier may need to remove the hoof wall over the affected area. 

Step 2: Apply Antibacterial or Antifungal Product

Once the infected tissue is removed, the goal is to stop further infection without damaging the healthy tissue. Unfortunately, no single product seems to be effective across the board. The following have been used with varied success: bleach, hydrogen peroxide, iodine, copper sulfate, and various commercial hoof disinfectants. Talk to your veterinarian for recommendations. 

 

If you prefer home remedies, these may be options for soaking your horse’s hooves or for squirt-bottle irrigation:

 

  • Apple cider vinegar (50/50 ratio with water) 
  • Lysol (2 oz. diluted in one gallon of water)
  • Borax (1 tablespoon dissolved in a half gallon warm water foot bath)
  • Bleach (1/10 ratio with water) 

Step 3: Guard Against Reinfection

White Line Disease thrives in dark, damp conditions. To keep the infection from persisting and spreading, it’s recommended that your horse’s hooves have plenty of exposure to air and stay dry. Some people will pack the separated hoof area with medicine or cover the affected hoof with an acrylic patch, but others feel these measures may actually produce the prime conditions for infection. 

Step 4: New Horn Growth

A horse’s hoof is similar to human fingernails, and therefore doesn’t repair itself; rather, it replaces itself. The hoof wall must grow out and replace the damaged portion, a process that takes several months to a year. Frequent trimming and proper shoeing will help keep pressure off the toe and make sure the hoof wall grows correctly. A hoof supplement program may also be helpful to ensure healthy new growth.


Hoof care is essential to keeping your horse healthy and happy, but don’t forget about taking care of the rest of your horse, too. All-natural skin care products from Equiderma can effectively treat a variety of skin conditions to keep your horse looking and feeling its best.

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