White line disease also known as "seedy toe" is a fungal infection of the horse's hoof. As the name suggests it attacks the white line which connects the sole to the hoof wall. It is sometimes mistaken for hoof wall separation but is not to be confused.

White line disease changes the typical light color of the white line to a black or dark grey color. It may also give off a foul odor. lameness can also be present and is in advanced disease. The disease May locate in the toe area of the hoof giving rise to the name "Seedy toe". White line disease may not be noticed by a horse owner and is most often diagnosed by a farrier  during  routine hoof trims or shoeing. It may affect horses of any age, breed or sex and can affect one hoof or all four.

White line disease is most often seen in moist, humid areas with annual rainfall. The exact organism that causes white line disease is not known but it is known to be caused by bacteria in the soil getting into a weekend spot in the hoof wall such as a crack which then sets up a fungal infection that leads to the disease. Who's infections are often attributed to poor management but with white line disease this is often not the case as it is seen even in horses kept in very clean stables and Facilities.

Cop-pure-cure of course.