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Fracture management in wild birds

The treatment of wild avian patients must be approached in a different way than that of companion avian species

13 February 2020, at 9:00am

Unfortunately, fractures are common in wild birds presenting to veterinary clinics (Howard and Redig, 1993). Many birds sustain fractures due to high-impact blunt trauma following collision with vehicles or flying into windows. Predation can also result in traumatic fractures, usually with associated wounds.

When injured wildlife are initially presented, they are often in a state of shock. Wild animals are not used to humans or handling and so coupled with the pain of injury, the car journey to the vets can be incredibly stressful. After a very brief assessment to look for any life-threatening injuries (eg active haemorrhage or severe open fractures), the patient should be administered appropriate analgesia and placed in a dark and quiet room.

Appropriate analgesia depends on the circumstance; however, in acute presentations the author prefers to use opioid analgesia. Butorphanol can be administered to most avian species at 0.5 to 4mg/kg IV or IM q1 to 4h; however, buprenorphine has been shown to have more efficacy in raptors (Ceulemans et al., 2014) and can be administered at 0.1 to 0.6mg/kg IV or IM q6h. Non-steroidal anti-inflammatories (NSAIDs) are not an ideal choice in patients on initial presentation, as shock and hypovolaemia can result in poor renal perfusion which, when coupled with NSAID administration, can lead to acute kidney injury. If an unstable fracture is present, then NSAIDs will be unlikely to provide an appropriate level of analgesia; however, they are an excellent choice for analgesia once the fracture is stabilised. Administration of subcutaneous or oral fluids can also help to treat shock; this is described further by Mullineaux and Keeble (2016).

Red kite safe handling
FIGURE (1) Wild birds, here a red kite (Milvus milvus), should be handled with each leg restrained appropriately to avoid injury from the talons

Identification of the species of bird is essential, as some species require more careful handling. Corvids such as crows and magpies have sharp beaks which can cause injury to the handler if the head is not adequately restrained. Birds of prey have sharp talons used for catching prey which can cause lacerations to the skin of handlers. Birds of prey should have each leg held securely at the level of the tibiotarsus to avoid “footing” behaviour where the bird strikes out with its foot and talons (Figure 1). The author recommends the use of an appropriately sized thick towel for handling all species of birds, to stop the patient from escaping and damaging their wings or feathers and to protect the handler.

Once the patient has been stabilised then a full assessment can be performed. Location of fractures can sometimes be narrowed down by the carriage of the patient. For example, fractures of the pelvic limbs often result in non-weight-bearing lameness in the affected leg. Injuries of the shoulder tend to result in dorsal rotation of the carpus so that the tip of the wing is elevated dorsally, whereas more distal thoracic limb fractures result in a dropped wing (Forbes, 2016). Pelvic or spinal fractures can result in a patient unable to move from sternal recumbency. Some fractures are obvious on presentation if they are associated with haemorrhage or an obvious compound fracture is present; however, others may require radiography.

Fracture radiography of a great spotted woodpecker
FIGURE (2) This catastrophic fracture of the right humerus of a great spotted woodpecker (Dendrocopos major) resulted in the euthanasia of this bird on humane grounds

Radiographs should be performed under general anaesthesia on stable patients to minimise stress. This allows for appropriate positioning and full evaluation of any fractures that may be present. A minimum of two contralateral views should be taken, unless the fracture is obviously catastrophic and clearly requires euthanasia (Figure 2). Splints or bandages can be applied as required under the same anaesthesia to minimise stress and handling to the patient.

The treatment of wild avian patients must be approached in a different way than that of companion avian species. The goal at any given time of treatment must be for the patient to be fully fit to release to the wild. Careful consideration must be employed in each case to ensure that after treatment the patient will have full return to function in order to hunt or feed appropriately depending on their feeding strategy, to avoid predators and to live an unencumbered life in the wild. For example, birds of prey must have full function of both wings in order to have the speed and agility to catch prey.

The goal is a return to function with as little rehabilitation time as possible, so as not to stress or imprint wild birds. Because of this a number of factors must be evaluated.

Is the fracture closed or compound? Compound fractures may be desiccated and devitalised, and they carry a higher chance of infection and subsequent osteomyelitis which may lead to non-union.

Is the fracture associated with an infected wound? If so, there is a poor prognosis for repair.

How old is the fracture? Fractures that already have a fibrous or bony callus present may need to be re-broken and splinted or fixated in the correct orientation to allow an appropriate return to function.

Is the fracture articular? Any fracture that is closer than 1.5 times the diameter of the bone to an articular surface is associated with reduced post-operative function (Forbes, 2016), which in wild birds will impact survival, more so than in companion birds with free access to food.

Will the bird require a lengthy rehabilitation period? If multiple fractures are present and there is a high risk of complications, then the welfare of the patient must be considered.

Is surgery realistic and do you have the skillset to treat the fracture? If you are not confident that the patient can return to full function following treatment, then it may be in the patient’s best interest to euthanise.

Unfortunately, due to the nature of the injuries that most wild birds sustain many fracture presentations will result in euthanasia. It is important not to view this as a loss, as a patient that is severely injured and not presented to a veterinary clinic would die of starvation or predation in the wild.

Analysis of wild raptors presenting to a rehabilitation centre over a three-year period by Howard and Redig (1993) reported a release rate of 36 percent for birds with closed fractures and 15 percent with compound fractures. They reported that wing fractures were the most commonly reported, comprising 86 percent of all fractures, with the humerus being the most commonly affected.

Simple, well-aligned fractures can be treated with external coaptation and/or bandaging techniques. More complex fractures can be fixed surgically, with techniques described by Calvo Carrasco (2019), Forbes (2016) and Ponder and Redig (2016), which will be described in part two of this series. Conservative management can include cage rest, which is indicated for non-complicated fractures of the coracoid or scapula (Figure 3). The use of external coaptation without surgical repair has been associated with poorer outcomes (Ponder and Redig, 2016); but they can be helpful in settings with lower budgets and with veterinarians not experienced in surgical fixation. Figure 4 shows a simple left tibiotarsal fracture of a juvenile rock dove (Columba livia) that was managed successfully with splinting. The focus must be on the welfare of the patient, and it must be ensured that the method of fixation does not cause overwhelming stress.

Ophthalmic Evaluation

Wild birds suffering from fractures often have had blunt force trauma which can also have affected the head. Birds have a structure on the fundus of their eye called pecten. This dark brown to black, corrugated structure is visible via direct or indirect ophthalmoscopy and is a vascular structure that functions to supply nutrition to the retina (Bayón del Rio, 2016). The retina and the pecten can be damaged when head trauma occurs, with resultant pectinal haemorrhage. Retinal detachment can also occur in severe cases, which carries a poor prognosis (Williams, 2008). If not evaluated and appropriately treated, posterior ocular trauma can go unnoticed, with wild birds being released that are unable to avoid predators, or visualise prey and subsequently sadly starve to death. It is essential that a full ophthalmic examination be performed on any wild bird prior to release.

In conclusion, when you are presented with a wild bird with a fracture it is important to evaluate the patient as a whole. Careful consideration should be taken to ensure the patient can be treated with minimal stress and intervention, return to a normal state and quickly be released back into the wild.

References
Author Year Title
Bayón del Rio, A.A. 2016 The Eye and Eyelids. In J. Samour, Avian Medicine, 3rd ed. Missouri: Elsevier, pp. 64-68.
Calvo Carrasco, D. 2019 Fracture Management in Avian Species. Veterinary Clinics of North America: Exotic Animal Practice, 22, pp. 223-238.
Ceulemans, S., Guzman, D., Olsen, G., Beaufrère, H. and Paul-Murphy, J. 2014 Evaluation of thermal antinociceptive effects after intramuscular administration of buprenorphine hydrochloride to American kestrels (Falco sparverius). American Journal of Veterinary Research, 75, pp. 705-710.
Howard, D.J. and Redig, P.T. 1993 Analysis of Avian Fracture Repairs: Implications for Captive and Wild Birds. In Proceedings of the Annual Conference of the Association of Avian Veterinarians. Florida: Association of Avian Veterinarians, pp.78-83
Mullineaux, E. and Keeble, E. 2016 First aid and emergency care. In E. Mullineaux, and E. Keeble, BSAVA Manual of Wildlife Casualties, 2nd ed. Gloucester: British Small Animal Veterinary Association, pp. 37-55.
Ponder, J.B. and Redig, P. 2016 Orthopaedics. In B.L. Speer, Current Therapy in Avian Medicine and Surgery. Missouri: Elsevier, pp. 657-668.
Williams, D.L. 2008 Raptors: ophthalmology. In J. Chitty and M. Lierz, BSAVA Manual of Raptors, Pigeons and Passerine Birds, Gloucester: British Small Animal Veterinary Association, pp. 278-283.

Ashton Hollwarth, BSc, BVMS, MRCVS, studied in Western Australia. Since graduation she has worked in exotic practices in England and is currently enrolled in her CertAVP Zoo Med certificate. Ashton recently started an ECZM residency in Avian Medicine and Surgery at Great Western Exotics.

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