Young hunters under 14 are being encouraged to kill as many wild cats as they can between now and June.
The winner will have the chance to win $250, so long as the cats don’t have a microchip.
SAFE spokesperson Will Appelbe said cats would suffer, and some would inevitably be companion animals.
"It’s bad enough that young people are being taught and encouraged to kill small animals," he said.
"There is little to no difference in the physical appearance of feral, stray and pet cats, and disqualifying dead cats with microchips is too little too late."
One person commented on a social media post made by the competition: "This is no way to teach empathy to children."
The writer added: "Feral cats might be wounded in ways that would cause long, painful deaths.
"While cats with microchips are disqualified, children won’t know this until after the cat has been killed – meaning companion animals are at risk."
DOC principal science adviser Craig Gillies said there was virtually no difference in physical appearance between feral and domestic cats.
One resident suggested to Newstalk ZB Canterbury that people could paint their cats to differentiate them from feral ones.
"Some cats don’t even like wearing collars, but cat paint they can’t take off," she said.
"If they try and lick it off, it’s not toxic."
Organisers of the hunting contest acknowledged public concerns but said competitors would be under adult supervision and would be urged to stay away from small rural towns.
Feral cats are estimated to kill 100 million birds in New Zealand each year.
