Chopper was held in the Tauranga dog pound for 271 days in the lead-up to Fraser's district court trial in July.
Judge David Cameron found Fraser not guilty of the charge, saying the vet bore responsibility for not taking adequate steps to prevent the attack. Chopper was released to Fraser's care that day.
At the High Court at Rotorua on Thursday, the council's lawyer Nathan Spier said Judge Cameron's conclusion that Fraser had a "total absence of fault" was not in line with what the law said.
"This appeal surrounds a question of law."
The substance of the appeal does not try to reconsider the facts of the case, Spier told Justice Edwin Wylie, although he added the question of whether Fraser had control of the dog "hasn't been examined before".
Fraser, who represented herself, told the judge she had "no comment" on the question of law raised by Spier.
Under the Dog Control Act, if convicted, Fraser must forfeit her dog for it to be euthanised unless she can prove an "exceptional circumstance". A judge could then order the requirement for the dog to be killed to be set aside.
At today's hearing, Fraser's submissions centred on her view this case was exceptional.
"This is a very unique case, what happened was exceptional. The District Court judge found I had taken all reasonable steps. I believe the decision of the judge was correct.
"The vet did not keep to their own arrangements. The actions of the vet wearing a face mask and coming out to the car [where the attack occurred] did not comply with her own safety arrangements."
Justice Wylie retired to deliberate for 15 minutes before granting the council leave to appeal.
"It is my view that there is a public interest in clarifying this point of law," he said.
"There are a number of people in court, with this hearing being covered by some media. Public interest in this matter does not seem to have abated."
Justice Wylie set down the substantive appeal hearing for March 2, 2023.
