Dog owners in Christchurch could be fined $300 for not carrying bags to pick up after their pets, or letting them near pathways in Hagley Park without a leash.
The rules are in force from today as part of a new city council by-law.
Dog owner Bridget Cameron was surprised to hear about the new rules.
Her pet was one of eight dogs off their leads at the time in Hagley Park.
Four would have breached the new by-law by coming within a metre of the walkways but Ms Cameron's pet was away from the path.
She said she was a responsible owner and already made sure her pet stayed away from cyclists and children.
"I did have an experience when he was a puppy, a little girl at a park ... and she screamed and absolutely was terrified of dogs so from that experience I've been really careful ever since he was a puppy to make sure he stays away from people."
The new rule was "crazy", she said. "It's a park ... it's not a good rule. What's a park for?"
Another dog walker, Paul Fitzharris, thought a fine for not carrying plastic bags to clear up droppings was a good idea.
"I guess it's the people that don't have their dogs on a lead, they don't know what they're doing when they're behind them.
"Very often they carry on and think, 'oh our dog's been very good and hasn't done anything' - but they haven't seen it."
Mark Vincent who heads the Christchurch City Council's animal control team, said fines would only be handed out to recidivist offenders.
"Officers aren't going to be going around checking everyone's pockets to make sure they've got bags.
"I mean it's about giving people the opportunity to say I have to be responsible, this is my dog, this is my responsibility to clean up after it.
"And if a person is observed that they're not doing that and they're not carrying a bag then that will obviously lead to some sort of enforcement action."
Under the by-law dogs must be kept on a short leash around pathways in Hagley Park.
"There are plenty of dog owners who use those retractable leads - which are quite effective sometimes - but if the dog is two or three metres away from you, running to the side, and trips somebody up or causes an accident the dog's obviously not under control."