STOCKTON (CBS13) — The mother of a boy with autism is pleading for the public’s help after her car was stolen in Stockton with the family’s dog in it.

“It’s devastating to have the car back and not the dog,” said Cynthia Niswonger.

Niswonger says the family’s two-year-old mix named Sloan was in the car when it was stolen Sunday afternoon from the parking lot of the McDonald’s off Martin Luther King Boulevard in Stockton.

“She is about 20 pounds, she looks like a little yellow lab,” she said.

Niswonger, her son and two friends were traveling from Oregon back home to Southern California when they stopped to get something to eat.

READ: Driver Who Allegedly Tied Up Dog With Wire Cited For Multiple Violations

“So we locked the car and left the AC running with the dog in the car and took the electric key fob,” she said.

A few minutes later, they saw a man driving off with their car and their dog. Niswonger chased after him.

“All I could do is yell ‘leave the dog, leave the dog.’ He definitely knew he had our car and that we saw him because he paused for a moment and thought about it and then he just took off,” said Niswonger.

Their dog Sloan was wearing a pink harness and leash. Immediately after the incident, the family put up flyers hoping she might have escaped.

The dog has served as a comfort to her 12-year-old son Neeko who has autism.

“We didn’t intend for her to be a therapy dog but she meshed with Neeko from moment one and the bond they have is amazing,” she said.

She says Neeko learns care, compassion and empathy through caring for the dog, and he often connects better with her than people.

READ: 11-Year-Old With Down Syndrome On Mission To Spread Awareness

“Why did he do that? I want Sloan back,” Neeko said.

Police found the car near 8th and American and dusted it for prints. Niswonger says the thief stole their luggage, medication and an iPad with speech software on it for Neeko. But all she really cares about is Sloan.

“Just bring her back. Put her in a shelter, call the number on her tag, call anyone on FB. Just bring her back. There are no questions I am gonna ask,” said Niswonger through tears.

The dog was not microchipped but was wearing a tag with Niswonger’s number on it.

She said the iPad is owned by the school district and may have GPS tracking on it. Authorities will check pawn shops and are also looking at surveillance cameras where the car was found.