In the ashes of what was once a luxury home on Malibu's Pacific coast, an energetic dog runs from spot to spot, searching for victims of one of the huge wildfires that ravaged Los Angeles.

Tulla, a sandy-colored Labrador retriever, stops next to a crusted gas canister that was once perhaps part of a barbecue, and begins to bark furiously.

To the human eye, there is nothing there, but Tulla's powerful sense of smell says otherwise.

Moments later, handlers bring in another dog, which also homes in on the same spot, offering a strong indication that the body of one of the dozens still missing from the massive blazes may finally be found.

Marco Rodriguez, of the Los Angeles County Fire Department, says the dogs are "critical" to the search effort.

"We have thousands of homes here in this area that have burned and approximately 15 people that have been reported missing.

"We're doing our best, and the dogs are an integral part of that," he told AFP.

For thousands of firefighters doing 12- or even 24-hour shifts, the last ten days have been back-breaking; hard physical work made even more difficult for those who have seen swaths of their city burned to the ground.

But for the dogs, it is something of a game, says Joshua Davis, who has deployed with Bosco -- a black Labrador -- from his base in San Francisco.

"They're used to crawling on rubble. They enjoy it," he said.

While there's no emotional toll on the animals, there are physical dangers that require special protective boots to safeguard their paws.

"There's a lot of sharp glass and a lot of nails and debris out there that can injure the dogs," said Davis.

- 'Like every other firefighter' -

The dogs in the search and rescue unit have routines similar to the humans they work alongside, said Davis.

"Every day we go to work, he gets fed, just like every other firefighter," he said.

"He gets training on various things and we do daily exercises with him, so he knows how to run on a treadmill and he can climb ladders."

When he's not on operations, Bosco keeps his skills up with a weekly session in a dummied-up practice disaster area, where trainers hide scents for him to find.

Bosco was originally trained to be a guide dog but "failed miserably" because he had too much energy, said Davis.

But that energy makes him perfect for searching -- where the dog has learned to associate the discovery of a scent with the chance to play with his favorite toy.

In Bosco's case, that's a piece of fire hose.

"When they find the scent, they'll bark at it. I'll get to the victim and/or the source where they're barking at, and then I'll reward Bosco," said Davis.

The dogs are not infallible and there are false alarms, but on the whole they drastically reduce the amount of work that humans have to do.

"A lot of the dogs here today can cover a building that has been collapsed in five minutes or less," said Davis.

"It can take four to five firefighters 10 to 20 minutes to cover a location."

For Bosco, who has worked alongside Davis for three years searching countless properties, it's not all serious labor.

In his downtime, he has a successful Instagram feed, where followers can see what he has been up to.

This week, one of his stories showed Bosco sitting in a car, looking enthusiastically through the window with an apt caption: "Ready to work, boss!"

AFP

A search dog can cover a collapsed house in five minutes, doing a job that would take five firefighters upto 20 minutes (Frederic J. Brown) Frederic J. Brown/AFP/AFP

Dogs prove invaluable in massive search for Los Angeles fire victims