The owner of George the goldfish — who underwent surgery to remove a head tumour last week — said the little fish was coming along "swimmingly".
Lyn Orton, the goldfish's owner, said George was expected to make a full recovery.
"He's back in the pond with the others and seems happy and bright," she told Fairfax Media.
"He's a tough little cookie."
George, 10, is a much-loved member of a large family of fish - 38, to be exact - who are aged up to 20 years, Ms Oroton said.
A self-confessed animal lover, Ms Orton and her partner Pip Joyce have gradually added more fish over the years to their pond, which includes fantails, black goldfish, and a baby goldfish "that could even be George's offspring".
Ms Orton, who works at the Lort Smith Animal Hospital's adoption centre, said she first noticed a small, white lesion on George's head about 12 months ago. Although it did not appear to be bothering him at first, the lesion kept growing, and eventually became a tumour.
"I was worried, and I knew Tristan [Lort Smith veterinarian Dr Tristan Rich] had performed similar surgeries in the past," she said.
"And the success with George has been amazing."
Ms Orton said she would spend money on any of her fish if they were ill.
"I love every single animal on the planet ... and George is a little being who deserves a chance as much as anything else," she said.
