White Line Disease

White Line Disease is a condition where the white line is separated from the sole of the hoof.  It is really not a disease, but an infection.  Bacteria, fungi, dirt and other opportunistic organisms can enter and infect the hoof wall.  Some reasons for the separation are mechanical stress caused by excessive toe length; environmental conditions such as excessive moisture softens the hooves allowing cracks to form; laminitis; and hoof imbalance.  It is more common in humid climates, but can occur in other areas.  Usually the horse does not seem to be in pain.  White line disease can cause lameness and lead to the displacement of the coffin bone if left untreated.  White Line Disease can affect horses of any age, sex or breed.  It can be in one or multiple hooves.   

It is usually diagnosed by a farrier or veterinarian who notices hoof wall separations during routine health care or shoeing.  Slow, poor hoof wall growth is commonly seen.  White line disease is not contagious.   Veterinarians don’t completely understand why hoof wall separation occurs.  It can be difficult to treat due to not knowing the exact cause of the infection.  It is also difficult due to the location and lack of blood flow to that area.  

Removal of the entire damaged hoof wall is the most important step in treating.  Most treatments include using a topical medication to treat the infection.  Regular cleaning of the area can help with treatment.  Some horses may need to be shod to protect their feet or have the edges sealed to prevent more damage.  It can take up to a year for the hoof to grow back.  Talk to your veterinarian and farrier for recommendations for your particular situation.  Prognosis is usually good, but the earlier it is diagnosed and treatment has begun, the better.  Some horses may have white line again, so monitoring for future infections is critical.

Prevention includes pick and clean hooves regularly and have regular trimmings by a farrier.  Keep the horse in clean, dry conditions.  Proper nutrition and regular health care is important too.   

The  American Association of Equine Practitioners has an article How to Manage White Line Disease that has a lot of pictures and goes more in-depth into the cause and treatment options.  The American Farriers website has an article Preventing and Treating White Line Disease .