REBECCA Henderson says the worst thing about the case of her missing puppy is not knowing what has become of him.
"He was just like a baby to us and it's the not knowing ... the not knowing if he's okay," Mrs Henderson said.
Mrs Henderson's 10-month-old Shih Tzu-Maltese Cross, Dusty, went missing on July 12, when he was playing on her family's rural property.
The Hendersons have a four-hectare property near Castlemaine, which isn't fenced off, and the family saw Dusty running outside at 11am.
They noticed he was missing at 1pm.
"We were at home and there's only a two-hour window he could have gone missing," Mrs Henderson said.
"He doesn't usually roam far."
Mrs Henderson, her husband Dean and their children Bailey, 14, Charli, 8, and Olivia, 6, are so distressed by Dusty's disappearance they are offering a $1000 reward to the person who returns him.
"It's consumed all of our time," Mrs Henderson said.
"If you didn't love your animals you wouldn't understand but I've had an overwhelming response from people who do understand and they've been really supportive."
Throughout the past two weeks, the family has placed "missing dog" notices in local school newsletters and many Castlemaine shops have been displaying a photo of Dusty.
Mrs Henderson said she thought if someone from the area had Dusty they would have contacted her by now.
"If it's someone from Castlemaine, they will know us," she said.
She said her property was close to the Steamrail Victoria line, and many people visited the area on weekends.
He was just like a baby to us and it's the not knowing ... the not knowing if he's okay.
She said the Hendersons believed someone visiting Castlemaine on the weekend of July 12 took Dusty.
"We believe he has wandered down there and someone has picked him up," she said.
But if the person wanted to return Dusty they could do so by contacting the Castlemaine RSPCA, she said, where they could collect the $1000 reward.
Mrs Henderson said the family was offering the reward in recognition of the fact people pay a considerable amount of money for puppies.
She said she was hoping the $1000 would be an incentive for people to return Dusty to the family.
Dusty is caramel in colour with black tips on his ears and tail. He has no collar.
If you know of Dusty's whereabouts, please contact the Castlemaine RSPCA on 5472 5277.