The owners of Australia’s beloved social media stars Molly the magpie and Peggy the dog have shared a heartbreaking update.

Australia’s favourite animal duo has faced yet another hurdle after animal experts tried to separate the pair.

Molly the magpie lives on the Gold Coast with Juliette Wells and Reece Mortensen after the pair discovered the bird on the ground at a local dog park four years ago.

The bird quickly became part of the family, making fast friends with their pet dog Peggy.

The duo became household names in March after Ms Wells and Mr Mortensen were forced to hand over Molly to be in captivity.

However uproar quickly led to Molly and Peggy — who have 972,000 followers on their Instagram account — being reunited and the couple granted a special licence to keep the bird. Then, in September last year, the Queensland Government’s Department of Environment, Science and Innovation tried to separate them.

The attempt was unsuccessful.

The moment Peggy and Molly are reunited

Now, the loving animal owners have shared a sad update about Peggy, revealing that the four-legged animal had an “aggressive little cancer on her left side near her ribs”.

The post details the cancer was only the size of a 10 cent coin but it needed to be dealt with quickly.

“It still doesn’t feel real. Peggy is the calm, nurturing soul in our little family, the girl who became famous without ever trying, simply by being herself,” the update reads.

Peggy the dog has been diagnosed with cancer. Picture: Instagram/@peggyandmolly

“She’s the gentle heart who nurtured Molly like her own and is the best MUM to Ruby, she opened her world (and all of ours) to the unlikely, magical friendship with a brave little magpie. She’s taught us so much about kindness, acceptance, patience, and unconditional love.”

The post asks followers to keep Peggy in their thoughts. Follow-up posts after Peggy’s surgery reveal the doggo was “a little wobbly and very sleeping from the sedation”. However the vet was able to remove all traces of cancer.

“They told us she was the best patient,” the post reads.

After some adjustments to Peggy’s medication she’s “slowly becoming herself again”.

Peggy and Molly became famous thanks to their unlikely friendship. Picture: Instagram/@peggyandmolly

All of Peggy’s cancer was removed. Picture: Instagram/@peggyandmolly

“Ruby is wondering why her mum isn’t chasing after her when she dangles her favourite lion teddy in front of her and Molly is wondering about Peggy’s Fishnet tshirt fashion choice,” the post explains.

Fans of the duo were saddened by the news that the loveable dog had been diagnosed with cancer.

“Sweet Peggy️. Sending love and prayers for a successful surgery and recovery,” one fan said.

Another wrote: “Sad to read. Sending positive healing thoughts to Peggy.”

“I’m so shocked and sad for you all. I’m sending all my positive energy and love,” another commented.

One added: “You filled us with love and now we return it in the form of prayers that God holds the hands of the doctors who are going to operate on Peggy. Kisses from Argentina!”

“Crossing everything for a successful procedure for sweet Peggy. Holding you all close in my heart and thoughts tomorrow,” someone else wrote.