Mayor Annette Main said while the petition organiser, Charlotte Goldsworthy, and HuHa animal welfare representatives were working constructively with council, threats against staff would not be tolerated and Whanganui Police were following up on those.
"We know that people have very strong opinions on this matter, but we ask that they treat our staff with respect," Ms Main said.
"The petition is a way they can present their view to the council in a forum where we can discuss it properly and are able to make decisions on the future practices at the pound," she said.
Julian Harkness, deputy chief executive, said animal control staff were carrying out their jobs in accordance with the council's practice, using the equipment they are provided with.
"We will not tolerate threats to any of our staff and have followed up these incidents with the police, who are taking action," Mr Harkness said.
He said the animal control team members did not make the decision about how dogs were euthanased, and that was a particularly unpleasant aspect of their job.
"Unfortunately, the pound has to deal with a large number of unwanted and abandoned dogs and dogs which aren't suitable for re-homing. We need to be clear that many of the dogs they deal with are not nice family pets that have been well cared for. They have come from irresponsible owners and we cannot risk placing them in new homes."
He said it was often difficult to find new owners for the dogs and council was urging people considering getting a dog to go to the pound to see whether there are any suitable dogs available.
Ms Main said staff had been having "a constructive discussion" with HuHa around the euthanasing of dogs, re-homing programmes and the wider operation of the pound.
"We expect that the petition will be presented at the (March) meeting and that the council will be able to move forward quickly with a review of necessary changes to pound operations and facilities in line with current animal welfare standards and practice.
"We've also had offers of assistance to improve animal welfare processes and services in the short term until the council can consider the petition. We appreciate the generosity of those people and will be following up with them," she said.
A Castlecliff dog owner told the Chronicle she had gone into the council offices and put a stop on her weekly direct debits for dog registration.
"I've got two dogs and I'm paying $10 a week. But after reading your story I went in and told them I was not paying another cent until they stop gassing the dogs," she said.
"The woman at the counter told me that other owners had done exactly the same thing.
"This council's quite prepared to spend $20,000 to groom Castlecliff Beach but in a few days time the sand blows back again. Why can't they spend some money on the humane treatment of dogs in the pound?"
The issue has attracted media attention around the country.
SPCA chief executive Ric Odom told TV One's Breakfast programme yesterday that while gassing the dogs was not illegal he expected the council to revisit its policy.
Mr Odom said following complaints about a year ago its inspectors had checked out the pound but did not find any breaches of the Animal Welfare Act. However, he said the SPCA recommended lethal injection as the most humane way to euthanase animals.
"The injection is quick, it's relatively painless and it's very effective. The problem with using gas is it can take quite a long time, several minutes, and there a lot of variables, so there are things that can go wrong.
"I would say that given the nature of the public backlash against this, I'd be very surprised if the council wasn't starting to reconsider their position," he said.