The Modern Equine Vet
December 2023
Vol 13 Issue 12 2023
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Cover Story | Lameness

Managing Recurrent Foot Abscesses That Bug the Horse

By Marie Rosenthal MS

Foot abscesses that continue to drain or recur are a “troublesome thing,” said Craig Lesser, DVM, CF, a podiatry specialist at Rood and Riddle Equine Hospital, in Lexington, Ky.

“The owners get really concerned by this,” he said at a Burst Session presented at the 69th AAEP Annual Convention in San Diego. However, a closer look usually finds a solution to help the lesions resolve.

Often, the reason for the recurrence is because caregivers take the bandage off and turn the horse out in the mud before the foot has a chance to heal. It quickly becomes packed with mud, which traps bacteria and reinfects the foot.

“And then we’re back to square 1 again. There’s no question in my mind that is the most common reason [an abscess recurs],” he said, so he typically suggests owners consult a farrier after the abscess is opened to get a shoe or treatment pad on the foot to protect it.

If it truly is a recurrent lesion—not a result of turning the horse out too soon—go back, do a thorough examination of the foot, check the drainage and the amount of inflammation, look for other areas of swelling and take some radiographs.

Dr. Lesser tends not to take radiographs the first time he sees the horse for abscesses.

“My rule of thumb is that if you can’t resolve an abscess in 3 days, I’ll take an X-ray. That first day that I show up, I don’t usually find a lot of value in taking an X-ray,” because it is not going to change treatment, and most simple abscesses will heal within a couple of days.

“But by day 3, that’s when I’m starting to worry that we might have some bone damage, and I need a little extra help to get this open,” he said. He takes lateral and solar margin images to look at the entire surface of the coffin bone to see if there are changes that require a different, more aggressive approach.

The traditional way to treat infected coffin bones is to debride and treat regional perfusions with antibiotics, but Dr. Lesser explained, “I don’t do those very often anymore.”

Instead, he lets his little helpers do that. He has been using maggot larval therapy because “I’m using fewer antibiotics, and they’re a lot faster at cleaning up these infections.”

They do a great job at debridement, he admitted. If using larval therapy, it is important to consult a farrier to place a shoe and a treatment plate on the foot to help keep them in place, as well as to keep the foot off the ground.

“The nice part is it [the plate] stops the ground from touching the bottom of the foot so these access pockets don’t get crushed over and over again. It continues to drain, and it keeps that area protected,” he said.

Owners might be a little squeamish because they must change the bandages every other day, and the larvae do increase in size as they feed.

“But it’s amazing how fast they clean out the infection. I’m using way fewer antibiotics, and everything’s nicely debrided after we’re done,” Dr. Lesser said. MeV


Maggot larvae used to debride the wound.
Image courtesy of Dr. Craig Lesser