Image copyright Facebook/Rescue Dogs Match Image caption Lana in 2015 after she was first returned

Lana the Labrador, once dubbed the saddest dog in the world, may have found a third lease on life.

In 2015, the dog found a home after a Canadian animal adoption group posted a heartrending photo of the young lab mix that went viral.

The second owner recently returned Lana, so the rescue group said she was again up for adoption and had until 20 May before possibly being put down.

They have since been flooded with some 5,000 emails and adoption offers.

"I'm sure we're going to find her a place," said Brenda Dobranski from Rescue Dogs Match in Cambridge, Ontario. "Third time's a charm."

The organisation admitted "there is still work to be done" despite "tons" of training when it comes to Lana's behaviour. They say she should ideally be able to spend the bulk of her time outdoors because she is "skittish" inside.

Ms Dobranski described Lana as being a bit like a cat in that she preferred to keep her distance.

Image copyright Facebook/Rescue Dogs Match Image caption Lana has had a hard time finding a permanent home

"When you see Lana she reminds you of the type of dog you want to hug and cuddle on the couch with," she said.

"She's not that type of dog. She's very touch sensitive from humans, she's just learning now that it's OK to play with other dogs. Right now the trainer that she's been living with can pet her on the head for a few strokes but then you see her body tense up."

Lana's story first made headlines in 2015 when the dog rescue group posted about how she "shut down" after being placed in a kennel. Her first adoptive family surrendered her after snapped at one of the owners over food.

She found a foster family and then a second adoptive home, but that too was short-lived.

While she is described a "loving and silly", she can be cautious around new people and "possessive" with her food, a behaviour that developed when she was a puppy and the runt of the litter.

Rescue Dogs Match says she needs a home with no other pets and no children, and a fenced in backyard. Lana turns three years old this month.

Ms Dobranski said that while Lana's story has tugged on people's heartstrings since first being featured on The Dodo, a website geared towards animal lovers, it is important not to adopt a pet simply out of emotion.

"People just want to save, and that's great - it's absolutely wonderful. But it has to be the right fit for the people as well as other pets and that specific dog," she said.

Lana was first brought to Canada as a rescue puppy from Mexico.

Ms Dobranski says her story helped Rescue Dogs Match raise C$15,000 (US$11,000/£8,500) for the organisation in 2015, funds that went towards medical bills and boarding for all their rescues.