Page 95 - June 2018 Speedhorse

Some Horses Are More Prone to White Line Disease
“Once a horse has gotten white line disease, even if it has been effectively treated and has cleared up and the hoof wall has regrown with healthy tissue, a few years later it may show up again in the same hoof or in another hoof,” says Good- ness. “I don’t know if there is an underly- ing problem with that horse’s immune system or if it is genetic. Some horses tend to be more susceptible.”
Some individuals, due to genetics and/or nutritional imbalances, just have poor hoof quality, with more brittle or weak hoof walls. “They just don’t hold up under the same kind of environment as the rest of the horses on that farm or in that stable,” he says.
The risk doesn’t seem to be environ- mental as much as it is in horses that have hoof capsule defects and flares. If a horse has a lot of toe, the feet often become dished. The normal hoof wall is designed to be worn away as fast as it grows - continuously produced and continuously worn away. The longer the hoof capsule just sits there without being worn away
or trimmed, the more vulnerable it is to infections. Long-footed horses, like gaited horses or any horse that develops flares and hoof capsule defects, are more vulnerable. In the unbalanced hoof, there is more stress on the white line, stretching it and creating openings for the pathogens to enter.
White line disease is often seen in laminitis horses because they don’t grow much toe very quickly. If the wall isn’t being replaced with fresh, strong horn in a timely manner, the old horn just sits there and becomes exposed to microbial infections. Horses with laminitis tend to have a dished, turned-up toe and a stretched white line, not allowing for a healthy, tight junction between the outer hoof wall and the sole. There are many fissures and separations, so these feet more readily get white line disease because this creates a perfect environment for the infection to become established.
The key to prevention is to keep the feet well balanced so there is a tight white line junction and no flares. Early detec- tion is also crucial.
White line disease is a progressive infection and subsequent separation of the hoof wall, with the wall coming loose from the foot. The cause of this hoof deterioration is usually a combination of bacteria and fungi that are commonly found in the horse’s environment.
a practice, and I remember telling the barn manager that I saw a little separation in one of If’s feet (If was the mare’s name), but told him that I would deal with it next month. It was just a small thing. But by the time I got back there the next month, it was huge! Sadly, it was impos- sible to resolve. It took years of effort before we gave up on that mare, and she ended up being euthanized - just because I put it off a month!
I had no idea that this problem could travel so quickly and affect a horse that severely. That was a lesson that was hard learned.
“If it is not effectively dealt with when you catch it early, the hoof-eroding infection can lead to pedal osteitis, a bone infection, or lami- nitis, which was what led to the demise of that particular mare,” he continued. “If you suspect white line disease, it should not be ignored or treated lightly.” It should be dealt with imme- diately and thoroughly.
TREATMENT
The treatment is simple - a thorough debride- ment of the hoof wall in the affected area, remov- ing every bit of the damaged horn, then providing some type of supportive shoe to support/correct the hoof capsule distortion. “Once you debride that area, you’ve weakened the hoof wall even more,” Goodness says. “We use various kinds of shoes, such as heart bars and sole supports to keep the hoof stable. The debrided area can sometimes be extensive enough that we have to use some type of medicated adhesive to rebuild a portion of the hoof wall to affix a shoe to.”
He usually combines the debridement with soaking the hoof in some type of antiseptic, like chlorine dioxide, because it is gentle on healthy tissues and it is broad-spectrum. The soak can get into all the nooks and crevices where there might be any remaining microbes. “This takes care of anything you might have missed during the cleanup process,” says Goodness.
Treatment for white line disease includes a thorough debridement of the hoof wall in the affected area to remove the damaged horn. Then, a shoe, such as a heart bar and sole supports,
is used to support and correct the hoof capsule distortion.
“Once you have exposed and cleaned the damaged tissue, you don’t want to let that area become overly dry as it grows out,” he explains. “The open area has exposed horny laminae and if that gets too dry, it creates more little cracks and opens up new avenues for the infection to either become established again or continue.”
White line disease is treatable, and the microbes that eat away the hoof don’t survive well in sunlight or exposed to air. “Those
of us who have dealt with it frequently now have some good methods figured out that are very effective,” he says. “It helps to leave the debrided areas open to air and sunlight. That’s really all you need to do if you’ve really cleaned it up thoroughly. You really don’t need to con- tinually medicate it. But to be safe, we usually use a topical antiseptic and I dunk these feet in chlorine dioxide as an insurance policy.
“The way I treat new infections that are just getting started (when I run across them during routine trimming/shoeing), is to mix copper sulfate with a little blob of silicone, supersaturat- ing the silicone with as much copper sulfate as will stick, and pack the little fissures with it,”
he says. “Copper sulfate is very effective to nip most infections in the bud on any horse. If we
see a little fissure, we scrape it out and pack it with the silicone/sulfate mixture and put the shoe right on top of that to hold it all in place. When we get back again a few weeks later for the next trimming/shoeing, it’s usually all very healthy- looking. If you can get away without chopping a big hole in the hoof, you are better off, especially if it’s a working horse that needs a strong hoof.”
For cases that are neglected or not noticed in time to treat early, more hoof wall may have to be removed to get rid of all the infected tissue.
“The lingering problems occur when farriers don’t recognize it when they see it, and when
it is not treated early enough or aggressively enough,” says Goodness. “They may see a little
hole or crevice, but they just slap a shoe back on without digging it out and treating it. Dealing with white line disease is often just a question of recognizing what you are seeing, and treating it. The sooner you deal with it, the better. It may be as simple as packing it with copper sulfate or a merthiolate-soaked gauze pad.”
SPEEDHORSE, June 2018 93
EQUINE HEALTH