Clinic for Small Mammals, Reptiles and Birds, University of Veterinary Medicine Hannover, Hannover, Germany
In the hand-rearing of juvenile raptors, diets with improper calcium and phosphorus equilibrium and inadequate dietary vitamin D3 can lead to malunion of bones.1,2
A 30-day old hand-reared juvenile steppe eagle (Aquila nipalensis) was presented at the clinic with a good weight, undisturbed general condition and with the inability to stand up. The bird was on a diet of one-day-old chicks without any dietary supplements. The clinical and radiographic examinations revealed malunions in all long bones as well as the lower beak (rachitis). The main clinical symptoms were caused by a high degree of recurvatum deformity of the right tibiotarsus which inhibited the stretching of this leg. The eagle was given a new diet of whole rats and mice to improve the bone density. At an age of 40 days a correction osteotomy was carried out under general anaesthesia with isoflurane (5% induction, 3% maintenance; CP Pharma GmbH, Burgdorf, Germany). A skin incision over the caudolateral palpable tibiotarsus was made, the fibrous tissue was bluntly elevated from the bone and retracted and a closing-wedge osteotomy implemented. The tibiotarsus was stabilized by two intramedullary pins (1.4 mm), performed in a retrograde fashion and positioned beneath the skin, and an external skeletal fixator type 1a consisting of two transmedullary pins (1.2 mm) in each bone fragment.1,3 The pins were driven through the bone from craniomedial to caudolateral to reduce soft tissue damage. Postoperative management included cleaning of the pins every three days, administering an antibiotic (enrofloxacin, 10 mg/kg SID, 7 days, Baytril®, Bayer Vital GmbH), antifungal treatment (voriconazole, 18 mg/kg SID, 21 day; VFend®; Pfizer) as well as pain management (meloxicam, 0.5 mg/kg SID/BID, 10 days; Metacam® 1.5 mg/ml ad us. vet., orale Suspension, Boehringer Ingelheim GmbH). Radiographs were taken after 7, 24 and 28 days. The fixator was removed after 21 days (visible callus formation) and the intramedullary pins after 28 days. Ten days after surgery the eagle was able to stand up without any difficulty and had regained full mobility of its legs.
1. Redig PT. the use of an external skeletal fixator-intramedullary pin tie-in (ESF-IM Fixator) for treatment of longbone fractures in raptors. In: Lumeij JT, Remple D, Redig PT, Lierz M, Cooper JE, eds. Raptor Biomedicine III. Lake Worth, FL: Zoological Education Network, Inc.; 2000:239–254.
2. MacCoy DM. Treatment of fractures in avian species. Vet Clin North Am Small Anim Pract. 1992;22:225–238.
3. Rochat MC, Hoover JP, DiGesualdo CL. Repair of a tibiotarsal varus malunion in a bald eagle (Haliaeetus leucocephalus) with a type IA hybrid external skeletal fixator. J Avian Med Surg. 2005;19:121–129.