"It's very sad for the boy and his family," said one resident, who did not wish to be named.
The property where the attack is understood to have happened is in a quiet residential neighbourhood about 50 metres away from Paengaroa School.
Paengaroa School principal Bruce Lendrem declined to comment.
He said he had been asked not to do so by the victim's family, who requested privacy.
Paengaroa Country Store owner Mukhtar Singh said the boy and his parents were regular customers at his store.
"When I heard the news I was shocked. He is a really nice boy. He and his mum often come into the store, as do his grandparents. They are a really nice family. I feel for the little boy and his family," he said.
Western Bay of Plenty District Council compliance and monitoring manager Alison Curtis said the unregistered long-haired heading-type dog had been put down after the owner surrendered it.
Ms Curtis said police were heading the investigation and it was unknown how the injuries happened, but the dog, which was believed to be owned by the boy's relative, had been seized by animal-control officers the same day.
It was too early to say whether the owner would face prosecution.
Ms Curtis said: "This dog was certainly not the poster-child for an attack, and we cannot stress enough how important it is that children should always be supervised around dogs, as any dog has the potential to attack given the right, or in this case, wrong set of circumstances."
Research showed the majority of attacks were committed by a dog known to the victim, and the attacker was likely to be a family pet or a relative's dog.
Ms Curtis said 28 reported dog-attack complaints were made to the Western Bay of Plenty District Council in the last financial year to June 30, 2015, and another 13 in the past three months.
That compared to nine during the same quarter last year.
Tauranga City Council animal-services team leader Brent Lincoln said there were 69 attacks on people in the last financial year - but attacks could involve as little as a scratch.
"No matter how good your dog is with children, young children and dogs should never be left unsupervised.
"It is the owner's total responsibility to ensure their dog is controlled at all times."
Police communication spokesperson Kim Perks said the investigation was in its early stages.
- Additional reporting NZME