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 areasof 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.
"We've spoken to all the trampers who have been heading out that way recreationally, and we've put signs up, but no one has seen her as yet."
Agnew said the couple had contacted a number of farmers in the area about Freida's disappearance, but so far none of them had managed to spot her.
"A member of the public who lives out in Maxwell has hopefully organised a couple of hunters to go out and look for her as well.
"You have to be pretty fit to go out there, because we're not looking on the trails any more, we have to go further into the bush."
Despite the couple notifying at least 19 hikers on the Waitahinga Trails over the weekend, and posting a photo of Freida to numerous social media pages, Agnew said her dog hadn't been seen since her initial disappearance.
"She's predominantly white and curly, with brown ears. She's wearing a red harness and a red collar."
If a member of the public has spotted Freida, call Scottie Agnew on 022 364 6474 or Helena Agnew on 027 632 7595.