Multicentric Septic Osteomyelitis and Arthritis Caused by Staphylococcus aureus in a Gyrfalcon (Falco rusticolus)

An adult female gyrfalcon (Falco rusticolus) was presented with a right-wing droop and weight loss. Radiographic images revealed osteolysis and osseous proliferation of the right shoulder and the mobile vertebra between the notarium and synsacrum. The tentative diagnosis was vertebral osteomyelitis secondary to septic arthritis. The bird did not respond to antibiotic and anti-inflammatory therapy and represented 10 days later, with feathers soiled with feces, an impacted, dilated cloaca, and an inability to stand due to spastic paralysis of the hind legs. The bird's condition did not improve with 24 hours of supportive care and its quality of life was considered poor; therefore, the patient was euthanatized and submitted for postmortem examination. Multicentric septic osteomyelitis and arthritis were confirmed in the mobile vertebra between the notarium and synsacrum and the right shoulder. Despite 10 days of antibiotic therapy, Staphylococcus aureus was isolated from within the 2 locations in which septic osteomyelitis and arthritis were identified. This report describes the clinical features, diagnosis, and pathologic findings of septic osteomyelitis and arthritis caused by S aureus in a falcon.