Lee arrived to find Wang Fuk Court complex engulfed in what would become the Chinese city's deadliest blaze in decades, with at least 151 people killed when seven high-rises were burned to charred husks.

The 43-year-old airline engineer joined the crowd waiting anxiously at a nearby school-turned-shelter on Wednesday for news on rescue efforts.

After midnight, as the flames grew, a district councillor told her that the search for pets had ended.

Then, just as all seemed lost, her phone rang. A firefighter called to ask if she had a dog in unit 2703 of the Wang Kin House tower.

A day after the blaze started, Jason reappeared, cradled in the arms of a volunteer after he was saved from the still-burning towers.

"He was still shaking when I saw him from afar, then I called his name, he saw me and stopped. Then he smiled," Lee told AFP.

"I was so happy I was out of my mind, I felt like I was in shock."

A firefighter later told Lee they were able to coax Jason into a carrier after spotting his name left on little notes she had stuck onto walls.

The firefighters had "also rescued my soul", Lee later wrote on social media.

- 'Will to live' -

The fire burned for more than 40 hours, and during that time Hong Kong social media was flooded with posts from worried pet lovers.

Pets are much-loved in the city, where pampered pooches are often pushed around the streets in prams, and shops selling animal outfits dot many neighbourhoods.

Animal welfare groups taking care of rescued pets shared pictures online, trying to match them to owners.

The SPCA in Hong Kong said 209 animals -- including dogs, cats, fish, hamsters, turtles and more -- were taken from the buildings, 63 of them had died.

District councillor Lau Chun-hoi said he still hoped more pets that survived, citing reports of strays.

"Animals have a very strong will to live," Lau told AFP, proposing that food and water be left out on some of the buildings' floors for them.

He urged people to check in on Wang Fuk Court residents who may have lost pets in the fire because "in their hearts, pets are family too".

Remembrance messages were being shared on social media.

"Be good when you get to the rainbow bridge, play with the older brothers and sisters, grandpas and grandmas from the neighbourhood," one user wrote.

Lee meanwhile called on the government to provide pet-friendly temporary housing, saying it was tough for displaced residents to arrange it on short notice.

The poodle had become timid and was reluctant to leave Lee's side.

But, Jason was going to be alright: the vet said, aside from mild dehydration, the dog was already back to his fluffy, perky self.