A young NSW woman has been forced to put down her beloved pet on the same day she was reunited with the rare cattle dog after a five-day search.

Ashleigh Taylor launched a wide-spread search with the help of locals after her ute was stolen on Sunday from outside Kimberleyland caravan Park in Kununurra, WA, with her best friend Flikr inside.

Truck drivers, helicopter pilots, rangers and neighbours helped scour the area after the 22-year-old’s plight went viral on social media and the cattle dog was found 10km from her home, despite the ute being located 400km away.

Ashleigh and Flikr are best mates. They've travelled Australia together and haven't been apart for more than six days. (Facebook)

A young NSW woman has been reunited with her 'best friend' cattle dog in rural Western Australia after an arduous five-day search. (Supplied)

A man speaking on Ms Taylor’s behalf posted a video on the Find Flikr Facebook page tonight reporting the 22-year-old had to put Flikr down after she showed signs of ingesting poison.

“One of Ash’s biggest fears was that Flikr might eat poison that the station put out for dingoes,” the man said.

“Unfortunately sometime this morning, just before Ash would’ve got to her, she’s eaten some poison.”

Ashleigh's ute was stolen on Sunday night, and dumped 400km away, with her pup still on the back. (Facebook)

He said Ms Taylor’s elation quickly turned to devastation when she noticed Flikr starting to show signs of poisoning.

“It takes a while to have an effect.”

“Ash has just had to put Flikr down so she couldn’t do this so I said I would do it for her.

“Worst update ever.”

(9news)

Ms Taylor is living 4000km from her relatives in Western Australia and said Flikr was the closest thing she had to family while she was working Moola Bulla station.

Her appeal to find Flikr was viewed by hundreds of thousands of times.

“We’ve travelled Australia together, I’ve had her since she was eight-weeks-old, and we haven’t been apart for more than six days,” she said.

Flikr is a two-year-old rare chocolate pure bred blue heeler. (Facebook)

She found the dog on a laneway coming home from Moola Bulla.

“She was coming back to me by herself, which is absolutely incredible," Ms Taylor said in a live Facebook video.

"I went and camped out last night where she was found, where she climbed a ladder and got into a tank on our station - which was 15 to 20km away from where she was left and across two paddocks.

"This morning, I drove back in, went around all the other tanks to put milk crates in them, in case she ended up in another tank."

Ashleigh and her friends have travelled to Halls Creek and are searching for Flikr. They've set a reward for her return. (Facebook)

Clothes with Ashleigh's scent are being left along the highway for Flikr to hopefully recognise. (Facebook)

Before Flikr was found, an emotional Ms Taylor described her to 9News.com.au as “my best mate, my family, I am utterly heartbroken”.

Police told Ms Taylor six children were responsible for stealing the ute, and let the dog out in an area called Bonjor Bore, 10 km from where the vehicle was dumped.