Rescuers using a bloodhound tracking team and an infrared-equipped search helicopter scoured the woods for the missing boy, but high winds and deep darkness forced them to call off their search until daylight Saturday.
"I believe that dog being with him is what kept him alive," Kershaw County Sheriff Jim Matthews told AOL News in a telephone interview today.
"I was with one of my officers talking to the helicopter crew when we got the call, 'They found him.' And I was like, 'Is he alive?' We worried there was no way, because of the coldness and because he had been out there all night.
"When they said, 'He's fine,' I'm thinking, Wow. How did that happen? And the answer is because of that dog."
Tyler was reported missing about 8 p.m. Friday by his mother, Jacklyn Marie Jacobson, 25, who said that the child left the bedroom where she and her boyfriend were watching a movie to get some juice, according to local newspaper The State.
Dozens of police officers, firefighters and sheriff's deputies searched the woods, some using bloodhounds, while the helicopter circled overhead in a search pattern. But the infrared was looking for a little boy alone -- and without knowing one of the family's two dogs was missing as well, they may have missed the pair, Matthews said.
"We're surmising that's why the helicopter crew could not distinguish the child. They picked up deer and other animals, but they just did not see a small child alone," Matthews told AOL News. Around 3 a.m., with the helicopter needing fuel and winds increasing, they decided the search would resume Saturday morning.
That morning, as dozens of police officers and firefighters headed into the woods with volunteer searchers, a man walking down the road said he thought he heard crying in the woods, Matthews said.
The crying boy and the dog, a mid-size black Labrador retriever mix, were found about a quarter mile from home. The child was cold but otherwise uninjured, Matthews said.
Emily DuBose and Linda Harr, who live in the house near where Tyler was found, said they heard the helicopters overhead Friday night but didn't know a little boy was missing.
They praised the dog, who kept close to Tyler.
"Just thinking that a dog would watch a baby over the night, it's kind of like a movie instead of real life," DuBose told the station.
Matthews said the boy's father is in the Army stationed in Hawaii, and was on his way back home. He described the living conditions inside the family's home as "deplorable," telling AOL News, "That's kind of a nice way of saying how nasty it is."
"We're going to have the Department of Social Services check the place out and make recommendations on how to make it more livable," he said.