Then doctors could then move on to the reconstructive stage - expected to begin early next week, he said.
"We'll most likely be transferring tissue from elsewhere on the body."
Dog bites differed to stab wounds and other injuries because of the force of the "crush" and tissue damage, he said.
Sakurako's healthy tissue would be used to repair her injuries, but it was still too early to tell which tissue was permanently damaged and unsuitable for the grafts.
"You can't always tell which tissue will survive."
The reconstruction of Sakurako's "ferocious" facial wounds would take time, Dr Moaveni said.
"The face is a delicate structure. When it changes, it can be such a difficult thing to reconstruct. It's going to take a number of stages ... [it] won't be complete until she's fully grown."
Middlemore Hospital intensivist Dr David Galler said intensive care was doing what it could to make sure Sakurako was comfortable and manage her pain.
Staff were finding it hard to dissociate themselves from the little girl's plight, he said.
"It's really tough."
Sakurako's family said in a statement they didn't know what to expect in the coming weeks and months.
"We have a long journey ahead, we simply wish to take things one day at a time."
They were grateful for the support they had received since the attack, especially from medical staff and the driver of a red car who helped to get their daughter to the hospital.
They said the best way to help them is to pray for Sakurako.
THE FULL UEHARA FAMILY STATEMENT
"We are a small family with one daughter, Sakurako, from a small island in the south of Japan.
We work in the food industry. We do not have a lot of family support back in Japan.
We would really like to thank all the professionals, paraprofessionals and particularly the Middlemore medical teams currently involved in Sakurako's care.
We would like to thank the driver of a red car who assisted us at the time of the accident and helped us get our little girl to the medical centre in Murupara. We don't know what to expect in the coming weeks, and months.
We have a long journey ahead, we simply wish to take things one day at a time.
We are grateful for all the various offers of support. Many people want to know how they can help, please just keep Sakurako in your prayers. We ask that you allow us our space so that we may focus our energy on our daughter Sakurako and her treatment."