Rescuers put plywood around the hole to stabilize the ground, and then widened the gap enough for a person to fit through.
Paveljack climbed down a ladder, uncertain of how the 100-pound animal would react to him after standing in 18 inches of cold water for an hour.
"He was intimidating. He was a big dog," said the firefighter, who once owned a German shepherd. "If he was mad, he could have attacked me. But he was just scared. He knew he was in trouble and he wanted to get out of that hole as fast as possible."
The plan was for Paveljack to lift the dog and bring him up the ladder, but the firefighter found himself sinking in mud under the weight of the squirming, wet dog.
"I had water rolling over the top of my boots," he said.
The firefighters up top lowered down the dog's leash and rope for a makeshift harness and hoisted the dog up while Paveljack followed up the ladder, pushing from below.
"It was beautiful thing," a grateful Moore told The Buffalo News. "He was wagging his tail, looking at all the people."
Moore, who couldn't be reached by phone Monday, told the newspaper that her leg had sunk into the hole but that she caught herself and crawled to safety. Her dog, she said, had run up from behind and toppled in.
Mack, she said, initially appeared to suffer only from a sore hip but on Monday was moving slowly and throwing up. She hoped to take him to a vet.
Meanwhile, a news photo of Mack showing his appreciation with a canine kiss to Paveljack's face has brought some heat from the rest of the firehouse.
"I'm catching a lot of stuff for the picture right now," the firefighter said, laughing. "I just love dogs. I wanted to check him out, and he just happened to lick me."