The people whose doorstep she showed up on did not recognise her, but neighbours said Winnie was the pet of the previous owners, who had recently moved.
Mr Auger thought the owners might have given up waiting and had to move house when Winnie didn't return.
Meanwhile, she had been slowly making her way back home on her injured leg.
"The cat can't really use its leg, it's been in quite a lot of pain. It would still be in some pain at the moment but it's now obviously on quite a lot of pain relief, so it's comfortable."
It would cost about $600 to amputate the leg, but because it was "save-able" and the cat was young and otherwise healthy, Mr Auger said they were hoping to fix the leg.
That would involve rebreaking it and restructuring it. The process would take about six to eight weeks and would cost about $1500.
"Obviously we would love to do things like that but funds are always short," Mr Auger said. "We would like to put a cry out to the Whanganui community to help little Winnie. She's a lovely, smoochy young cat."
Mr Auger said Winnie had "used up one of her nine lives at least" but deserved a second chance.
"We would love to give that a try," he said.
-To donate to Winnie, go to wanganuispca.org.nz and click "make a donation" and leave a message that it is for Winnie. People wanting to donate can also go into the SPCA on 134 London St or the SPCA op shop on Victoria Ave. Donations can be made by either cash or Eftpos.