"I'm not connected to any one group. I'm trying to spread the net as wide as I can," he said.
He's not collecting money, but sometimes people want to donate, either to animal welfare bodies or to his journey. He saved before starting the trip, and has a Givealittle page.
He prefers to walk on quieter roads - which wasn't possible last week on his walk from Stratford to Whanganui.
He grew up in Wellington, and has worked in animal welfare in both New Zealand and Australia - especially training and handling dogs. He became burnt out while working in a big Melbourne shelter and returned to New Zealand with two dogs, 6-year-old pug cross Jake and 12-year-old chihuahua cross Piccolo.
The walking trip is because he wanted to carry on helping animals, in a different way. He was also keen to experiment with minimal living.
His homemade camper on bicycle wheels is light enough to pull. Piccolo rides in it most of the time, but the more adventurous Jake does a lot of walking.
At night the camper is propped up to stay flat and all three sleep in it. It contains cooking gear, has a solar panel on top, is insulated and ventilated and is their home.
Public toilets are easy to find, and sometimes people invite Mr Brassett to set up in their backyards.
He has a Facebook page and a blog - search the internet for The Longest Walk New Zealand.