Bilateral coxofemoral degenerative joint disease in a juvenile male yellow-eyed penguin (Megadyptes antipodes)

Abstract

A juvenile, male, yellow-eyed penguin (Megadyptes antipodes) with abnormal stance and decreased mobility was captured, held in captivity for approximately 6 weeks, and euthanized due to continued clinical signs. Radiographically, there was bilateral degenerative joint disease with coxofemoral periarticular osteophyte formation. Grossly, the bird had bilaterally distended, thickened coxofemoral joints with increased laxity, and small, roughened and angular femoral heads. Histologically, the left femoral articular cartilage and subchondral bone were absent, and the remaining femoral head consisted of trabecular bone overlain by fibrin and granulation tissue. There was no gross or histological evidence of infection. The historic, gross, radiographic, and histopathologic findings were most consistent with bilateral aseptic femoral head degeneration resulting in degenerative joint disease. Although the chronicity of the lesions masked the initiating cause, the probable underlying causes of aseptic bilateral femoral head degeneration in a young animal are osteonecrosis and osteochondrosis of the femoral head. To our knowledge, this is the first reported case of bilateral coxofemoral degenerative joint disease in a penguin.

Fat chance? Endangered penguin rehabilitation has mixed conservation outcomes

“…Moreover, underweight (<5 kg) chicks that fledged from wild locations had a slightly higher probability of post‐fledging survival (0.28) than rehabilitated chicks (0.23). Emaciated seabird chicks are more likely to develop growth issues, including bony deformities (e.g., Buckle & Alley, 2011), and higher corticosterone levels (e.g., Kitaysky, Kitaiskaia, Piatt, & Wingfield, 2006) which might explain the lower survival probabilities for rehabilitated yellow‐eyed penguin chicks. However, given that the expected outcome for these emaciated chicks was starvation if no intervention had taken place, even a reduced post‐fledging survival is assumed to be of conservation benefit if this translates into recruitment, and if greater gains would not be achieved by expending resources elsewhere.…”

Sphenisciformes, Gaviiformes, Podicipediformes, Procellariiformes, and Pelecaniformes

“…Bilateral degenerative joint disease was diagnosed in a free-ranging, juvenile, yellow-eyed penguin with abnormal stance and decreased mobility (Buckle and Alley, 2011). Among adults, 16% of rockhopper, 4% of gentoo, and 2% of king penguins examined at a zoo in the United Kingdom had osteoarthritic changes, most commonly affecting the coxofemoral and stifle joints (R. Pizzi, personal communication).…”