This is labor intensive but I highly recommend giving it a try three times a day if possible but if not......daily.
Pick out the hooves.
Scrub clean getting into every crevice. Use an old dandy brush or scrub brush. Use warm water if possible and add a squirt of anti-biotic dish soap such as Dawn.
Rinse with clear water and pat dry.
Spray with a mixture of unpasteurized apple cider vinegar and teatree oil. (Mix up a batch using ten to fifteen drops of TTO to about four cups of ACV).
Something that is very good is to use the anti-biotic that is used to treat mastitis in cows. One treatment over three or four days using two tubes should make a difference. Sorry, the name eludes me right now....maybe DryCow or something like that.
Hope this is of some use to you. I had very good results with the scrubbing and spraying daily. At the very least.......be sure to pick out the hooves daily!
^^ This, especially the scrubbing/cleaning advice. The cow stuff is called Today or Dry Cow. It's only about $2-3 a tube, so not that costly of a fix. I have used it before, squirting it in to the crevice between the heel bulbs on a mare with contracted heels.
Another good drug-store remedy is daily topical treatment with a 50-50 mixture of Neosporin Plus Pain (or generic triple antibiotic ointment plus) and human Athletes Foot Cream (1% Clotrimazole). You want to load it in to a syringe without a needle that has a longish tip on it, so you can really get it in to all of the cracks, crevices, and depressions in the bottom of the foot.
Links: New Page 15 Healthy Hoof - Solutions for Barefoot Performance Healthy Hoof - Solutions for Barefoot Performance
- has some treatment listings.