A yellow-eyed penguin is ready to return to the wild after life-saving care that included a toe amputation at Wellington Zoo.

The endangered hoiho - nicknamed Buster- was taken to the zoo's The Nest Te Kōhanga facility after suffering a bite to the foot.

The injury caused severe bone and tissue damage, and infection of the injury led to inflammation in the bone of its toe, leaving it with a severe limp which had left it unable to walk.

Wildlife and avian specialists led by Veterinary Science Manager Dr Lisa Argilla administered a course of antibiotics, pain relief and anti-inflammatories to reduce the infection and swelling. However, the toe joint had been badly damaged and began to erode.

"In a case like this, we have the options to either try to fuse the joint with a bone graft, or look at amputating the toe," said Dr Argilla. "In consultation with Department of Conservation, we chose to amputate the toe, as a bone graft would have required a much longer stay in hospital."

Buster's inflamed toe wasn't the only complication. As well as suffering from anaemia of chronic disease, where an animal's health continues to struggle as they fight off infection, Buster was close to going through his seasonal moult.

"For surgical procedures with birds, we have to pluck any feathers around the area," said Dr Argilla. "If we had tried to do the bone graft, we would have had to pluck newly grown feathers - which would have meant he was at The Nest Te Kōhanga for ages. The amputation meant we could avoid plucking feathers, and get him home in a much quicker timeframe.

"It's always a tough call to amputate, but we knew it would give this precious species the best chance to survive and thrive. In the wild, these birds are under the careful eye of the Yellow-Eyed Penguin Trust and Department of Conservation, so they would be able to respond quickly if Buster ran into trouble in future."

Buster made a swift recovery after the amputation, and within weeks was swimming in a saltwater pool.

"He has been using his foot very well, and has been swimming, walking and preening as he normally would," said Dr Argilla. "We've been in touch with Department of Conservation and the Yellow-Eyed Penguin Trust to make arrangements to return Buster to his wild home later this week."

Buster will be returned to a beach near Penguin Place, a rehabilitation facility on the Otago Peninsula. His progress will be monitored before deciding on where he will be released to in the wild.

Yellow-Eyed Penguins are one of the rarest penguins in the world and unique to New Zealand. They can be found in the South Island, with nesting sites scattered in the coastal forests, scrub, or dense flax. The population is declining due to land clearing and habitat destruction.

Wellington Zoo was New Zealand's first zoo and is home to more than 500 native and exotic animals.