This is a diseased condition of the frog, accompanied by a very offensive discharge from the cleft. It may be brought about by standing in moisture, on foul litter, the absence of pressure to and undue paring of the frog, etc. It is generally an indication of bad hoof management.
Thrush does not often cause lameness, unless there be much disease and sensitiveness of the frog; and frequent dressings with Stockholm tar or carbolic acid spread on tow, which should be pushed into the cleft and crevices, will, in most cases, effect a cure. If there is lameness, fomentations and poultices (charcoal poultices) will be necessary. To prevent thrush, as well as to cure it, the hoof should be kept as dry as possible, the frogs unpared by the farrier, and pressure allowed them by lowering the wall of the hoof as much as may be necessary, and applying thin shoes.