Fungal osteitis of the axial aspect of the mid body of the medial proximal sesamoid bone in a horse.

The satisfactory outcome of fungal osteitis in an 8-year-old American Quarter Horse is described. The horse was admitted with a grade 4 out of 5 lameness and exhibited metacarpophalangeal synovial effusion, indicative of a mild suppurative inflammation. Results of initial radiographic and ultrasonographic examination were unremarkable. Intra-articular anesthesia of the metacarpophalangeal joint allowed localization of the insult. It was not until day 6 of hospitalization when lytic changes on the axial aspect were observed on radiographic examination. Arthroscopic examination permitted identification and debridement of the affected bone. Fungal culture of the bone yielded Pleosporales spp. The horse was sound at the time of discharge after 12 days of hospitalization. No complications occurred in the post-operative period and the horse resumed his initial level of activity and competition in barrel racing. Key clinical message: To our knowledge, this is the first description of successful outcome of a fungal osteitis of the sesamoid bones following arthroscopic debridement. We hypothesize that the satisfactory outcome is associated with early recognition of the condition and aggressive debridement of the lesion arthroscopically. Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.