He went back and checked the property again.
"I came around and had a look and the gate was wide open and I thought 'what the heck'."
It was then he realised Pippin wasn't there and they began searching, for two hours, trying to find her.
They thought she could be lost but began to fear the worst when Pippin's collar was found.
"We got a phone call from a lady walking her dog on York St, who found the collar by York St kindy.
"She thought Pippin had slipped the collar, but someone had undone it," said Mrs McCullough.
"Even if someone had found her or let out as a prank, as soon as someone takes the collar off it implies they want to keep her," said Mr McCullough.
Mrs McCullough said Pippin is a placid dog who doesn't like loud noises and, like their other dog, Millie, rarely barks.
"She would go with anyone, she's really friendly."
The family have had her for almost a year.
She was a rescue dog from a farm but "quickly become a part of the family".
It's been an unhappy start to the new year particularly for brothers Tobey, Bede and Jude, who said they missed her a lot.
"She's so cuddly, they were always cuddling her," said Mrs McCullough.
The boys had been taking turns holding her collar.
"Jude's been sleeping with the collar at night."
The McCulloughs had a message for whoever might have taken her.
"Just leave her somewhere safe, anonymously, the pound or the SPCA.
"We just want her back."
Pippin is a big black and tan huntaway beardy with flecks of white, and some scarring on her back legs.
She is between 3 and 4 but looks older than she is.
She is registered and microchipped.
The family have notified the police and a photo of Pippin has been widely shared on social media, but as of yesterday afternoon the family is still looking for her.
-Ring the Times-Age on 06 378 9999 if you have any information.