International Dog Day (August 26) this month is pushing the message that it's better to adopt, not buy.
Each year, Sydney Cats and Dogs Home reunites about one third of dogs that come into its care. It also, on average, re-homes about 350 unclaimed or surrendered dogs annually.
The home's animal team manager, Renae Jackson, says shelters, pounds and rescue groups in Australia are overrun with dogs.
"Many the product of irresponsible, unregistered breeding practices," she said.
"By choosing to adopt rather than shop you are not encouraging unregistered, unmonitored backyard breeders but are helping to save a dog's life and give it a loving new home."
Minister for Local Government Shelley Hancock says the government provides half-price pet registration for anyone adopting a rescue dog from council pounds and shelters and re-homing organisations.
"Anyone buying an animal from council pounds and shelters as well as 95 rehoming organisations can benefit from a 50 per cent discount on pet registration fees as part of the government's efforts to make dog ownership more affordable," Mrs Hancock said.
"Since 2015, 43,000 pet owners have saved a total of nearly $1.2 million in reduced pet registration fees."
Mrs Hancock says all pet owners can help reduce the numbers of dogs and cats ending up in pounds and shelters.
"The easiest way to reduce the numbers of lost and unclaimed dogs needing to be rehomed is to follow the three easy steps of responsible pet ownership - microchipping, de-sexing and registering your pet," she said.
"Keeping contact details up to date on the NSW Pet Registry also helps ensure a joyful reunion should your beloved cat or dog be lost, stolen or injured."
Sutherland Shire Animal Shelter and Sydney Dogs and Cats Home at Carlton offers dogs for adoption.
Heathcote MP Lee Evans is also encouraging Sutherland Shire residents to consider giving a pre-loved dog a new home.
"Rescue dogs make wonderful and loyal companions," he said.
"Re-homing abandoned or lost dogs also reduces the burden on pounds, shelters and re-homing organisations and, importantly, helps lower euthanasia rates."