Chronic equine proliferative pododermatitis (canker) is a chronic hypertrophic disease of the hoof, denoted by an excessive proliferation of the horn-producing tissues, which results from a dyskeratosis of the keratinocytes. It occurs mainly at the frog and sulci regions, but can sometimes also affect the heels, sole, bulbs or hoof wall. The etiology still remains unclear. Infectious agents such as anaerobic bacteria, viruses, spirochetes and fungi have been isolated from diseased tissues, but, moreover, an immune cause has been suggested, possibly related to a genetic predisposition. This report shows a case of a Brazilian Sport Horse, 10 years old, that had been affected on the right hindlimb for more than two years without a concise diagnosis. Success was achieved with the treatment consisting of oral prednisolone and topical Purple Mush®.