This paper describes seven cases of fatal infection by the bacteria Pseudomonas aeruginosa in the avian nursery unit of Africam Safari Zoo during two outbreaks in 2007 (three cases) and 2008 (four cases). The affected species include three golden eagles (Aquila chrysaetos), two scarlet macaws (Ara macao) and two horned guans (Oreophasis derbianus). With the exception of the horned guan chicks, all animals were hand-fed in the nursery unit; they also shared the same environment. Four of the seven cases died without clinical signs. The main lesions in the golden eagle and horned guan chicks were necrosuppurative omphalitis and pneumonia, whereas macaw chicks had hydrocoelom, fibrinous pericarditis and suppurative airsacculitis. One horned guan also had necrosuppurative osteomyelitis in the skull. P. aeruginosa was isolated from the lung or the pericardial exudate of all cases. Additionally, one eagle had cryptosporidiosis in the bursa and cloaca, and crop emphysema attributed to clostridiosis.
Cultures were performed on samples obtain from the facility, equipment, material and animals inside the nursery unit in 2008. P. aeruginosa was isolated from all the materials related to the feeding of the golden eagles and macaws. The source of the bacterium was believed to be the quail meat that was used to feed the eagles.
P. aeruginosa is an opportunistic, gram-negative bacteria that affects immunosuppressed patients.2 It is common in human hospital-acquired infections and avian incubators and nurseries.1,2 Avian neonates may be susceptible because their immune system is not fully developed.1
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2. Samuelson, J. 1999. Infectious Diseases. In: Cotran R.S, V. Kumar, and T. Collins (eds.). Robbins Pathologic Basis of Disease, 6th ed. W.B. Saunders Company, Philadelphia, Pennsylvania, USA. Pp. 329–402.