The boy was treated at the scene and given pain relief by St John staff from Turangi then was taken to Taupo Hospital where his injuries were dressed.
There the decision was made to fly him to Waikato Hospital by Youthtown Trust Rescue Helicopter so he could be seen by a paediatrician and surgical team.
Mr Harvey said the boy would most likely need reconstructive surgery to repair the damage to his lips and mouth.
"The injury was quite localised to the mouth area, so it wasn't full facial ... but it was very much something that was needed to be seen by the surgical team at Waikato."
Last week, a 13-year-old Te Puke girl was bitten on the top of her arm by a neighbour's pitbull. Although her injuries were not serious, the girl was traumatised by the attack. She was now startled and frightened by the sound of the family's own dog barking, her mother said.
The pitbull was destroyed.
Nearly 12,000 people suffered dog bite injuries last year, including more than 1700 children aged under 10 - many of whom will be left with scars.
ACC claim statistics showed the 11,708 claims made by dog-attack victims in 2011 were at a cost of $2.4 million.
Of those claims, 872 were for children under the age of five, 891 for 5-9-year-olds (the highest for any age bracket) and 705 for 10-14-year-olds - similar figures to 2010.
The number of attacks requiring medical attention has increased since 2003 when 8677 people were attacked.