The Bay of Islands SPCA is still appealing for information on a dog found emaciated and with neck injuries that required surgery.
Inspector Wendy Locke said the around 2-year-old Staffie-cross, now named Lacey, was found near Mangamuka at the end of December.
Her ribs and hip bones were jutting out while the wound around her neck was the worst case of a collar growing into a dog's neck Ms Locke had seen.
At this stage, there had not been any promising leads in locating Lacey's previous owner, Ms Locke said. Last Friday, Lacey had surgery to stitch the skin back together around her neck and she was spayed.
She has put on 2kg since being rescued. It was likely Lacey's wound had been inflicted over a long period of time, Ms Locke said.