The owner of a dog who bit off part of a woman's lip is appealing the conviction and sentence she received for the attack.

Gretel Fairbrother, a promienent lawyer, was sentenced to 200 hours of community work and fined more than $15,000 in March.

Today in the High Court her lawyer Nicollette Levy said Fairbrother wasn't at fault over the 2013 attack in Porirua.

Leading up to it, Fairbrother had control of the English bull terrier, Levy said.

The bitten woman, Linda Harrison, had been talking to Ms Fairbrother and patting the dog for about five minutes before he bit her. Levy told the court that just because the dog could move enough to bite the woman's face, that didn't mean he wasn't under control.