A tiny koala joey has been given a second chance at life thanks to staff at Werribee Open Range Zoo.

The little koala was brought into the zoo by a wildlife carer about four weeks ago, after she fell from a tree in a blue-gum plantation logging area.

In the wild, at 150 days old and weighing less than 500 grams, the koala joey would usually still have been in her mother’s pouch.

A veterinarian (not from the zoo) made the difficult decision to euthanise the joey’s severely injured mother.

Werribee Zoo vet nurse Jess Rice said that when the koala joey was first brought in, it was unclear whether she would survive.

“She was just at the stage where she would have been starting to poke her head out of mum’s pouch,” Ms Rice said. “Joeys that size don’t have a good survival rate in care.”

After the koala joey was x-rayed, staff at the zoo put a cast on her fractured arm.

The native animal needed around the clock care, including feeding with a marsupial milk replacer every four hours. Ms Rice also introduced the koala joey to a temporary surrogate mum in the form of a stuffed toy.

Thanks to the care of zoo staff, the little koala started putting on weight and earlier this month, she was deemed strong enough to be released back to a specialist wildlife carer.

“It will be more than a year before she’s old enough to be released into the wild, so she needs to be with a carer with the resources to take care of her for that long,” Ms Rice said. “Koalas are just one of the native animals we have to be so careful to take care of in Victoria and that we have the privilege of helping at Werribee Open Range Zoo.”