If you own a dog that attacks a person or protected wildlife and causes serious injury to the person, you commit an offence. You can be liable on conviction to imprisonment for a term not exceeding 3 years or a fine not exceeding $20,000, or both. The court will also order your dog to be destroyed, unless the court thinks the circumstances of the attack were exceptional.
If your dog attacks protected wildlife and causes its death, or injures it so badly that it needs to be put down to end its suffering, you also commit an offence. You can be liable on conviction to imprisonment for a term not exceeding 3 years or a fine not exceeding $20,000, or both. The court will order your dog to be destroyed, unless the court thinks the circumstances of the attack were exceptional.
The court's decision is based on the circumstances of the attack, and you can find more information about the laws related to dog control in the Dog Control Amendment Act 2003.