"Our hearts are full and we can finally have peace after so long," he told Open Justice.
The 2-year-old rottweiler was released from the Tauranga pound on Tuesday afternoon after his owner, Helen Fraser, was cleared of responsibility for the attack in a reserved judgment released earlier the same day.
Fraser was charged with owning a dog causing injury in October after Chopper lunged at vet Liza Schneider, who was preparing to undertake a consultation for a desexing surgery.
Chopper was seized by Tauranga City Council on the same day.
The council alleged that Fraser did not take adequate steps to prevent the attack, which resulted in Schneider suffering a broken ulna, deep puncture wounds and muscle and nerve damage. A plate and six screws were surgically put in her arm.
Fraser's defence was that the vet's act of approaching the dog while masked and speaking loudly spooked the animal.
Judge Cameron ultimately agreed with Fraser's recollection over Schneider's, stating: "Significant details immediately preceding the attack may not have been accurately recalled [by Schneider].
"On the other hand, Ms Fraser as a witness to the attack had no reason to exaggerate those details. I prefer the evidence of Ms Fraser as to what occurred."
Judge Cameron also labelled one of Schneider's explanations regarding her preference not to muzzle the dog as "unconvincing".
"[Schneider] was in a position to take appropriate steps to maintain and exercise control. She failed though to take any steps to maintain and exercise control, despite having every opportunity to do so. Had she done so, the incident would have been avoided.
"I consider that Dr Schneider put herself in the position where she was vulnerable to attack by a dog who had not been assessed for safety purposes."
Speaking about the judgment, New Zealand Veterinary Association chief executive Kevin Bryant said the group was disappointed with the ruling.
"We've got a situation here with a highly trained and experienced veterinarian, who does a lot in the animal behaviour space and who I would rate as someone with a high degree of knowledge.
"To have those perspectives not considered in the judgment is really disappointing."
Schneider also serves on the association's member advisory board, speaking to her degree of experience, Bryant said.
A High Court appeal could also now be on the cards for Tauranga City Council, which has not ruled out taking further legal action.
"The decision to prosecute a dog owner is not taken lightly. We generally only take this kind of step on the most severe matters and in this instance, we believe it was appropriate given the seriousness of the attack," a spokesperson said.
The council will take time to review the decision before deciding on the next steps.
Bryant said if the council was to appeal the decision, the group would be "very supportive" of further proceedings.