Ornithobacterium rhinotracheale in Nestling Falcons

Abstract

This case report describes a severe outbreak of airsacculitis caused by Ornithobacterium rhinotracheale (ORT) in a large falcon breeding farm. Forty young falcons hatched from artificially incubated hatching eggs and were raised by hand for 5-8 days after hatch. Afterwards they were placed back with the parents. Three days after being with the parents, the stock breeder observed that the young falcons stopped begging for food, their crops were empty, and approximately 20% of the young demonstrated respiratory distress. However, all adult falcons and the older young birds appeared to be healthy. Two young falcons died and were submitted for laboratory investigations. A postmortem examination on the two dead falcons and ten 4-wk-old cockerels and baby rats used as feed for the falcons was performed. ORT of serotype A was isolated from lungs and air sacs of both falcons. Samples of the cockerels were positive by ORT PCR. Samples of the baby rats were negative. All young falcons were treated with a long-acting tetracycline (100 mg/kg i.m. followed by a second injection 3 days later). The falcons improved within the next 2 days, and only one additional chick died. According to the available literature, this is the first report of ORT in falcons causing severe clinical disease and outbreak in a breeding farm.