Regulatory services manager Doug Scott said it was important to note that the Dog Control Act 1996 did not give the council authority to put a dog down unless it had been signed over by the owner or they are granted a destruction order by the court.
"The animal control team have managed to have five dogs suspected of attacking stock in Waverley signed over and euthanised," said Mr Scott.
"The only time a dog can be euthanised without permission from the owner or the courts is when it is required to stop an attack that is taking place.''
Co-ordinator for the community patrol group in Waverley, Laraine Sole, said the council had been doing its best to solve the problem but had to rely on public information.
"Some people are unwilling to share what they have witnessed and some owners must have seen their dogs coming home with blood on them after these attacks," she said.
Ms Sole and other members of the community patrol group drive around the community at night and have chased a number of wandering dogs home.
"For about the last three months, I haven't seen any dogs on the streets so these recent attacks must have happened in the very early hours."
Police Senior Sergeant Greg Hogan of Patea said the latest attack was being investigated.
"Police do ask anyone with information to contact us. "Alternatively, information can also be provided anonymously via the organisation Crimestoppers on 0800 555 111."