Missing Down syndrome boy found safe

A missing Down syndrome boy has been found after disappearing from his home at Nambucca Heads. (AAP)

A missing Down syndrome boy has been found after disappearing from his home at Nambucca Heads. (AAP)

The mother of a four-year-old Down syndrome boy who has been found after disappearing on NSW's mid-north coast believes his pet dogs kept him safe.

A family's pet dogs helped keep safe a four-year-old Down syndrome boy who went missing overnight on NSW's mid-north coast, his mother says.

Cold and covered in scratches, Riley Martin was found sitting on the ground in bushland near Shelley Beach just after 7am (AEST) on Thursday.

He and his three pet dogs - two fox terriers and a kelpie - hadn't been seen since midday on Wednesday when he disappeared from his home in Nambucca Heads.

A couple from Kempsey saw an appeal for assistance on NSW Police's Facebook page and immediately drove to the area to help with the search.

They found Riley on Thursday morning with one of his dogs.

"We heard a dog bark, we almost stood on him," the unnamed couple told the Nine Network.

"He was covered in scratches and cold."

A man ran down a nearby street yelling "we have found him" to the boy's mother Bianca.

Footage of an emotional reunion showed Ms Martin grabbing hold of Riley and collapsing to the ground.

"Has he had water?" she asked.

"He's been through the bush. Those dogs kept him alive. Words can't describe it."

The boy was checked by paramedics and taken to Macksville Hospital as a precaution, police said.

Police, emergency services workers, volunteers and neighbours had scoured the area around Riley's home until Wednesday night. Local police kept searching overnight.

Acting Superintendent Shane Cribb from Mid North Coast Local Area Command said Riley had wandered about 1km from his home.

"He took three dogs with him and they kept him company throughout the night, which was probably something that kept him with a bit of warmth," he told ABC Radio on Thursday.

"That might have been enough to get him through the night but I suppose we'll never know."

Supt Cribb was surprised the boy was found in quite good condition given the circumstances.

He also praised the many volunteers and emergency service workers who helped in the search, including some who travelled from Grafton.