White Line Disease

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186 – March/April, 2017

By HEATHER SMITH THOMAS

White line disease is the common term for a progressive infection and subsequent separation of the hoof wall—with the wall coming loose from the foot. This problem usually starts at the bottom of the foot and travels upward as this area between the hoof wall and the inner structures becomes hollowed out. Travis Burns, Lecturer and Chief of Farrier Services at Virginia Tech (the Virginia-Maryland Regional College of Veterinary Medicine), says some people are confused about the name of this infection. “White line disease affects the non-pigmented stratum medium of the hoof wall (the white zone between the outer hoof wall and the inner portion), and not necessarily the white line on the bottom of the foot,” he explains.

Dirt, debris and bacteria can pack into the white line, especially if there is a bit of separation due to spreading forces when weight is placed on the foot. These forces are accentuated with a long, untrimmed hoof wall or when the toe is too long. “If dirt and bacteria get forced in there, the horse’s foot may develop an abscess, or in some cases certain bacteria may cause this progressive erosion of the foot. White line disease is the result of microbes infiltrating the non-pigmented stratum medium of the hoof wall,” he says.

The problem is generally noticed first by the farrier during routine trimming or shoeing. When the dirt/debris along the white line is removed with a hoof knife, an open undermined area is revealed, filled with powdery material. “There may be large areas of separation inside a normal-looking hoof wall,” says Burns.

“The number one treatment that I prefer, and which most farriers prefer, is debridement to cut away all the damaged/diseased area. It should be cleaned out until there is a healthy-appearing margin. This exposes the affected area to UV light and oxygen, which is the most important thing.” The hoofeating microbes thrive best in a dark, anaerobic environment (without oxygen).

“After the area is debrided and clean, you can treat it topically with any number of antiseptic products like tincture of iodine, Thrushbuster or chlorine dioxide. If the area is not debrided sufficiently, with a healthy-appearing margin, you are wasting your time and efforts because the disease process will simply continue,” says Burns.

Click here to read the complete article
186 – March/April, 2017