It took until June 10 for any action, when an animal control officer "who was familiar with the owner of the dogs warned them about their behaviour".
"The dogs were unregistered but the staff member has since entered them into the council system and an invoice for registration has been sent to the owner," Mr Barrett said.
Following a spate of incidents involving roaming dogs, Mr Barrett spoke to the Chronicle this week.
With regard to the June incident, he said the animal officer had to assess the risk at the time.
On the owners facing no penalty as yet, Mr Barrett said officers had some discretion and there were a number of ways to deal with such situations, including removing the dogs and fines.
"We have to try and build relationships to get compliance," he said. "I wouldn't pre-judge what the next step is."
Mr Barrett denied the owners were getting away with it and said complaints needed to be treated on a case-by-case basis. "It might just take us longer to get a fair outcome."
In a situation where officers feared for their safety, approaching the household with more than one officer or with police officers could be an option, he said.
"With these sort of things there are always lessons to be learnt," Mr Barrett said.