Symmetrical multipartite of lateral fabella in a small breed dog

An 11-year-old, female, Maltese dog was presented with abdominal distension and intermittent slight lameness on left hindlimb. Palpable abdominal pain and purulent vaginal discharge were observed on physical examination. Severe leukopenia with toxic change, and azotemia, hyperphosphatemia, and hyponatremia were identified on blood profile. On radiographs and abdominal sonograms, remarkable soft tissue mass containing echogenic material deviating intestines craniodorsally compatible with pyometra. On stifle radiographs, 4-5 fragmented sesamoid bone (fabella) was identified on both stifle joint with medial patella luxation. Immediate ovariohysterectomy was performed and the patient was recovered well with normal blood work. No specific treatment was attempted to the left hindlimb showing minimal and intermittent lameness. No remarkable abnormal gait was reported for 3-month follow-up period. The fragmented lateral fabella is considered congenital multipartite of lateral fabella not related to the lameness.