The dog had been classed as menacing. Dogs with this classification have to be contained in a yard, and muzzled on a lead if in public.
While Wairoa Mayor Craig Little expressed his sympathies to the boy, he said the attack showed "there's no future for menacing dogs in Wairoa".
Mr Little said he did not know the circumstances around the attack, or the family involved, but expressed his sympathies to them.
"My heart goes out to that little boy," he said.
The attack enforced why Wairoa District Council needed to continue taking a hard line on dog control.
Mr Little said there was "no room" for dangerous breeds of dogs if the community wanted Wairoa to be a better place.
"[Wairoa] stands out as one of the councils that are hardest on dogs in the region," he said.
"But we are because this is the sort of thing we don't want to happen.
He struggled to understand why people "choose to have these aggro dogs", as there was always the chance they could attack people, "and there's a good chance that could be a baby or a child".
If people chose to own dogs classed as menacing, Mr Little said they "needed to keep their dogs controlled, or keep them locked up."
As of September there were about 83 dogs classed as menacing in Wairoa district.
Over the past 12 months, there have been 208 reported dog attacks. Compared with previous years, this was an increase, however the reports ranged from a nip on the ankle to a full-blown attack, and included dogs attacking each other.
An investigation is under way into the attack.