Birdie braces

Macaw beak 016For some, the word orthodontist stirs awkward teenage memories of braces and the agonising wait to be rid of mouth metal. But humans aren’t the only species requiring some orthodontic alignment.

University of Queensland Small Animal Hospital Head of Avian and Exotic Pet Service, avian specialist and exotics luminary Bob Doneley is occasionally called upon to fit what he calls “birdie braces” for beaks that have gone awry.

Wry beak, or scissor beak, as it is known among bird circles, is a condition predominantly of juvenile birds, where the maxillary beak begins to deviate laterally – usually (for unknown reasons) to the right.

As a consequence, mandibular keratin tends to proliferate, unchecked by natural wear that would occur in the case of perfect beak alignment, and pushes upwards. This places additional pressure on the maxillary beak, worsening the defect.

“It is probably more common in macaws than other species but any bird can get it,” Doneley said. This includes ostriches which, due to their sheer size, can present with spectacular cases of wry beak. (Doneley’s ostrich practice once extended from Kingaroy to Tenterfield, and from the Gold Coast to St George – so he’s seen a few ostriches in his time). Doneley has also seen the condition in eclectus parrots.

Early intervention may be enough to solve the problem.

“Sometimes it is a matter of the owner simply holding the beak in correct alignment for ten minutes, two to three times a day,” Doneley said. “But as a general rule, by the time the owner realises the problem is there and then by the time they bring it in to us, the problem has usually got past that stage.”

Many affected birds will continue to eat, albeit awkwardly. However, the condition can progress to the point where it causes obvious discomfort to the bird.

“The potential for a detrimental impact on the bird’s health means this is something we need to treat.”

There are multiple theories as to the underlying cause.

“It may occur due to a genetic predisposition, and may or may not be directly hereditary,” Doneley said.

“A lot of affected birds are hatched from artificial eggs, causing some people to ask whether there has been some malpositioning within the egg – could the beak be pushed against the eggshell while the animal was growing? That could be just enough to cause a deformity.”

Doneley feels this was the likely aetiology in the affected ostriches he saw.

Another hypothesis, given that many of these valuable birds are hand-fed, is that trauma during hand-feeding may lead to wry beak.

“Birds often hit their beak vigorously against the spoon,” Doneley said. “Though I used to see this condition a lot in ostriches and they were never hand-fed.”

Yet another theory suggests that poor parental nutrition leads to affected offspring.

Trying to eliminate possible hereditary problems in birds is no simple matter. Desexing macaws is not as straightforward as spaying a dog or cat – and complicated by the fact that most are sold as breeding pairs. Added to this is the value of many of these birds.

“Blue and gold macaws sell for around five to seven thousand dollars,” Doneley said. “Many owners are worried about how the deformity might impact on the resale value of these birds.”

When it comes to the question of how to treat affected birds, there are a number of potential options, all with their limitations. The aim is essentially to apply gentle pressure to the beak until it straightens.

“People have tried corrective trimming of the beak with a Dremel , trimming away the abnormally growing parts of the beak which aren’t in wear,” Doneley said. “Trimming the beak back into normal conformation may allow the beak to self-correct, but this strategy is usually not that effective and often combined with another technique.”

Some avian veterinarians swear by a ramp which is built up from the mandibular beak, often using acrylic with k-wire as scaffolding. The ramp exerts constant pressure on the maxillary beak as it grows, eventually correcting the problem.

“The idea is that you build the ramp high enough so that when the bird opens its mouth to fullest extent, it can’t pull the upper beak over the ramp.”

The biggest limitation with this technique is that ramps need regular replacement.

“The problem is that keratin on the lower beak is growing continually, so you may need to replace the ramp every few days in a juvenile bird,” Doneley said. “In an adult bird you would be replacing it two to three times a month until beak corrects.”

Some practitioners drill holes in the beak and anchor the ramp into place.

Benign neglect is an option, albeit risky as some birds will experience serious difficulty eating.

“With ostriches we often left them as most were too big to do anything, but I did treat one ostrich chick with a mandibular ramp made from needles and acrylic with a good outcome.”

For pet and aviary birds, Doneley’s preferred technique is trans-sinus pinning.

“You basically take K-wire and run it through the bird’s skull, just behind the nares, so actually through the frontal sinus, in through the right and out on the left, anchoring it with a rubber stopper on the right side to stop the device from pulling through.” The rubber stopper is usually the cap off a blood collection bottle.

Where the wire exits on the left, Doneley bends it so that it runs down the side of the beak.

“At the bottom of the beak you create a little hook in this wire, then you use a rubber band to go around the hook and around the tip of the beak.”

K-wire is preferred as this has just enough spring in it to provide gentle tension. Juvenile macaws are highly adept at eating foreign bodies, so it helps to anchor the rubber band to the hook with Leucoplast.

The procedure is naturally performed under a general anaesthetic, usually isoflurane. Doneley prefers to intubate birds (typically with an appropriately –sized uncuffed endotrachael tube) to ensure the airway is controlled throughout the procedure, which involves a lot of movement of the bird’s head.

“The whole procedure takes about ten minutes,” he said.

Over the following weeks, as the beak continues to grow, the wire gently pulls it into alignment.

“The last one we performed took about three weeks to come completely back to normal – plus an additional week for the pinholes to heal up.”

Despite the distinctly Frankensteinian appearance of the device, most birds tolerate it surprisingly well.

“We give them pain relief on the day of the procedure but it doesn’t seem to cause a great deal of discomfort,” Doneley said. “It’s a very lightweight framework. While some birds aren’t impressed with this structure on their head, most maintain a good appetite.”

It is the owner’s job to maintain placement of the rubber band, which some birds remove with their claws.

“It was an owner who came up with the idea of covering the rubber band with Leucoplast tape and we now use this as part of our technique. The potential is always there for the bird to eat the rubber band, but if they did I would hope that it would pass. We have seen feeding tubes removed from the stomachs of macaws so it is something we look out for.”

The procedure costs around $400-500.

“You don’t need to radiograph these birds, just place the device. Most owners are prepared to do this and prepared for the aftercare.”

Bob Doneley will be co-teaching a workshop with David Vella on Approaches to Avian and Exotic Patients in Sydney in July. For further information visit www.cve.edu.au

Anne Fawcett

Pictures Bob Doneley