WLD – Short for White Line Disease.
Which is not really a disease per se. It is a similar infection to thrush, at the difference that it will attack the white line.
The white line is between the sole & the wall, connecting both together.
The origine to WLD is not the gravel coming in and creating a space where the infection can spread. It is the other way around: the white line wasn’t perfectly tight and “invited” the gravel to come in.

So WLD can and should be topically treated to prevent further deterioration. However, if you do not fix the cause for a non tight white line, you’ll always have the same problem.

WHAT ARE THE MAIN CAUSES?

Causes frequently are:
– mecanical, wall too long, creating separation between wall & sole
– nutritional problem, the feed not being properly adapted to the horse’s need leads to weakened laminae (internal part of the white line to simplify), thus wall separation. That will be very prevalent on laminitic or foundered horses and with lamellar wedge (see bellow what lamellar wedge can look like).