Whanganui couple Helena and Scottie Agnew have spent the past five days looking for their dog, Freida, who went missing on the Waitahinga Trails on Thursday afternoon.
The trails, 12km past Bushy Park, have areas of dense bush.
Helena Agnew said Freida, a 4-year-old border collie/bull terrier cross, had been on a lead for the entire hike until husband Scottie was forced to release her momentarily so they could navigate past a fallen tree trunk.
"That was her opportunity to just take off," Agnew said.
"My husband was out there until nine o'clock that evening, calling and searching. We think she might have got snagged on something because the bush is really dense out there.