Gwinnett authorities have broken up an illegal dog breeding program they say was operating in the backyard of a home in unincorporated Norcross.

Nine chihuahuas and six pit bulls were discovered May 24 by a Gwinnett County animal welfare official, Gwinnett police Cpl. Deon Washington said Thursday. Four of the pit bulls were pregnant and “appeared to be near delivery,” he said.

An animal control officer on patrol observed a “Puppies for sale” sign in front of a home on Williams Drive, Washington said. No one answered a knock on the door, so the officer later observed several dogs in a fenced area in what appeared to be a backyard breeding area.

The owner came outside when the dogs began barking. The animal control officer informed the owner that he was in violation of the Gwinnett backyard breeder’s ordinance, which says a person must hold a license from the state Department of Agriculture.

The owner was not cited for the violation because of officer discretion, Washington said. The owner has been educated on the Gwinnett ordinance that governs breeding, and he agreed to surrender the dogs to Gwinnett animal welfare officials. Washington said there will be additional patrols in the area to ensure the activity does not resume.

Two female chihuahuas with puppies have been released to The Society of Human Friends, Washington said. The other dogs are at the Gwinnett animal shelter and are eligible for adoption.