The pet industry is rejecting claims it promotes puppy mills.
The lobby group Paw Justice launched a campaign called Don't Trade Me this week, with the aim of stopping the practice and curbing unregulated back-yard breeders.
A puppy mill is a factory farm where dogs are bred for commercial purposes and are often kept in substandard conditions.
The current Animal Welfare Act stipulates that animals must have food, water and shelter, but does not specify how often dogs can be bred or the impact frequent breeding has on them.
Pet Industry Association spokesperson Tony Fraser said it was not in the best interest of pet stores to buy from bad breeders, as the stores were businesses that rely on keeping their customers.
"You will find some breeders that appear to be good to start with and when their puppies arrive they are not good.
"And normally they are then returned by our members to the breeder and we will communicate with other members and say watch out for puppies from this source."