The 1920s wooden cottage on Plymouth Street was gutted by the fire.
Missy was given oxygen at the scene before being rushed to a veterinarian clinic four doors away.
Wanganui Veterinary Services vet Peter Verhoek said a close eye was kept on Missy overnight before she was allowed to head home this afternoon.
"She recovered reasonably quickly from the smoke inhalation. She's been chipper as. It's been great," Mr Verhoek said.
"[Her owners] were pretty distraught yesterday.
"[But today] she's on her feet, eating, wagging her tail, just like a normal pup."
Mr Wilson said firefighters had thought Missy was dead before she was picked up from the bedroom floor.
"We expected it to be dead with the heat. But it was down low, laying on the floor. There's normally a certain amount of fresh air at that level," Mr Wilson said.
"Another guy scooped it up off the floor and passed it to me, and as that happened it sort of twitched and we knew it was still alive."
Mr Wilson said it was a natural instinct to perform CPR on anything that was struggling to breathe.
"Just like you would with a person, really, except I didn't put my lips around [Missy]," he said.
"A lot of people would do the same. We've done it before with dogs and cats.
"A lot of people, it's their life companion, so they're important.
"Part of our training is all about protecting and saving life and then [worrying about] property. You just do it - the instinct is to save anything."
