The cat, called "Bruce Almighty" by rescuers, was discovered last week with its paws and legs wrapped so tightly with electrical tape that the feline suffered tissue damage and infection in its limbs.
The Regina Humane Society hoped to raise $5,000 with a campaign on gofundme.com to cover the cost of treatment.
By Sunday, it was already past $11,000.
Bruce Almighty has undergone hours of surgery and staff at the society say a decision will be made Monday on whether to amputate a front paw.
Executive director Lisa Koch says Bruce is alert and eating, and staff hope he'll pull through.
"We're going to see if we can see some further improvement in those paws, in particular on his front legs, before we decide what our next steps will be," Koch told radio station CJME.
The black-and-white cat was reported Wednesday to the humane society when someone spotted him in northwest Regina.
The society has asked anyone with information about what happened to get in touch.
Koch said all money left over from Bruce Almighty's treatment will be put to good use.
"We're going to see a huge influx of animals over the next couple of months who are also going to be in need of care. So the gofundme is really going to help Bruce Almighty as well as animals who are really going to need it," she said.
News of the fundraising campaign's success touched the prime minister's wife, Laureen Harper, who has previously used her Twitter feed to promote cat causes.
"Great to see a happy ending to this story," Harper tweeted on Sunday night.