HABERSHAM COUNTY, Ga. -- It was 5:00 on a Wednesday night in a rural north Georgia county. Barking echoed through warm spring air. And kept going.

The phone rang at the Habersham County Department of Animal Control. Finally fed up, an anonymous caller complained about the barking. It was a routine call. Until officers arrived.

Officers discovered one of the state's largest puppy mills. Hundreds of animals were living in deplorable conditions. Rows and rows of plastic tubs housed dogs living in mud and feces. Matted hair made it hard for some of them to walk, to eat, even to move. Inside a nearby shed, the yapping reached a fever pitch. Smaller dogs were stacked in crates. Some were young, tumbling puppies. Others were older, cowering and growling in the corners.

SCENE PHOTOS | Habersham Co. puppy mill bust

The next day, the Humane Society of the United States sent in their Animal Rescue Team. They found more than 350 animals including dogs, cats, donkeys, pigs, chickens, ducks, doves, bunnies, a horse and an alpaca. The HSUS said the animals were living in unsafe and unsanitary conditions and "in need of urgent veterinary care."

“No animal should be forced to live in conditions like we’ve seen today,” said Jessica Lauginiger, manager of animal crimes for the HSUS.

Habersham County's Animal Control Director Madi Hawkins was appalled.

"We never expected to discover something of this magnitude in our own backyard," she said. "This is a heartbreaking situation, and it’s not an easy task to be present to witness this kind of cruelty.”

The animals were transported to an emergency shelter to receive emergency medical care. The animals will stay on the property as a case to remove them moves through the judicial process.

When asked about charges for the owners of the property, the HSUS said it's an on-going case.

Despite rising awareness, the Humane Society of the United States estimates there are still 10,000 active puppy mills in the United States.