Injured koalas have received life-saving treatment after surviving devastating bushfires on the New South Wales mid-north coast.

Key points: The Crestwood Drive fire on the NSW mid-north coast has burnt through almost 3,000 hectares of critical koala habitat.

The Crestwood Drive fire on the NSW mid-north coast has burnt through almost 3,000 hectares of critical koala habitat. Fears are still held for up to 350 koalas thought to have died in this fire

Fears are still held for up to 350 koalas thought to have died in this fire A search for burnt koalas will continue over 10 days, with seven so far treated at the Port Macquarie Koala Hospital

The first rescued koala was admitted to the Port Macquarie Koala Hospital after it was found in burnt bushland south of Port Macquarie, by a member of the public.

"This little koala was curled up in a ball on the burnt ground," hospital clinical director Cheyne Flannagan said.

"He was so dehydrated: Another day or two and he would have been gone."

The koala was treated by hospital staff for dehydration and given fluids during the first 24 hours in the hospital's ICU unit.

A fire-affected koala receives treatment at the Koala Hospital in Port Macquarie. ( ABC Mid North Coast: Wiriya Sati )

"He drank 400ml of fluid which is a lot for a little koala," she said.

"Post-fire they have nothing to eat, nothing to drink. They struggle."

Seven koalas have been admitted to the hospital, including a mother and joey that escaped unburnt.

"Out of those seven, four have been reasonably badly burnt. Their fur has been singed," hospital president Sue Ashton said.

"Their little paws, four little paws have all been blackened and quite badly with burns."

Koalas suffering burns are placed under an aesthetic before the burns are cleaned, creamed and bandaged.

Sue Ashton said the recovery period could take anywhere between six to nine months.

"It really depends on the koala," she said.

A koala that survived the out-of-control bushfire south of Port Macquarie recovers in hospital. ( ABC Mid North Coast: Wiriya Sati )

Waiting for the trees to grow

While the koalas currently in care are expected to make a full recovery, it will be months before they can be returned to where they were found.

The Crestwood Drive fire has burnt through almost 3,000 hectares of critical koala habitat.

Ms Ashton said they would need to wait for the food supply to rejuvenate before the koalas could be released.

"We will still try and release them exactly where we found them because koalas live in populations and they need to stay in that area where that population is," she said.

"We'll keep them here and we'll keep feeding them — what we call 'room service' — everyday, fresh leaves until that habitat returns enough for us to take them back there."

Volunteer search and rescue teams will continue to search the burnt bushland over the next 10 days for injured animals.

Staff are worried there could be many more animals out there yet to be found, with up to 350 koalas are thought to have died.

"We haven't actually gone into the search area where the high-density koala population is," Ms Ashton said.

"That's what we are fearing most, a lot will have been basically charred alive."

Koala Hospital staff search a core koala habitat south of Port Macquarie. ( ABC Mid North Coast: Kirstie Wellauer )

Promising signs of life after separate fires

Further south of Port Macquarie, a fire in the Crowdy Bay National Park also burnt habitat of a disease-free koala colony on Saturday October 26.

Volunteers from Koalas in Care Inc rescued two severely burnt koalas from the fireground, but believe most escaped unscathed.

"There are still pockets of green feed in there, so all is not lost," Koalas in Care facility manager Christeen McLeod said.

"It could have been a lot worse.

"Out of a bad situation, to get two burnt animals at this stage out and check 20 that seems to be a pretty good outcome for a fire."

The injured koalas are being cared for in the Koalas in Care Inc Taree facility.

They are still hopeful that koalas from this colony, free of chlamydia, would play a vital role in the recovery of the species on the mid-north coast.