An employee at the shop outside which the attack happened said the woman came into the store afterwards.
"It looked like a bit of skin came off her leg. It was a pretty deep wound," she said.
"She cried a bit and we sat her down and calmed her down."
She said a few locals also came to the woman's aid.
The employee gave her a Panadol and antiseptic cream.
Mr Currie said the woman was recovering at home today.
"Our animal management team is continuing to investigate, checking whether there is CCTV footage available in the area and working with witnesses to build a clearer picture of the attack," he said.
"Because of the time of the incident and sequence of events, no one has been able to identify the dog or its breed. No clear indication of where it went after the incident has been able to be ascertained either. Subsequent patrols today have also not located the dog and we're exploring the possibility the dog and its owners may be from another district."
Mr Currie said the attack was a timely reminder for all dog owners about the importance of keeping their dogs on a leash.
"If anyone knows anything more about this or has any information, please contact us at council on 0800 846 846."