Max, an 11-week-old Malinois puppy, was taken Saturday from owner Shaila Sheikh's home in Concord, California.
Police have since put out notices, asking the public to help catch the thief.
Sheikh, a nurse in the emergency room at a local hospital, was at work when it happened. Her family only had Max for two weeks when he went missing, stolen from his kennel by what looks to be a man on a bike, Sheikh told CNN.
"I was heartbroken," she said. "Max was helping us start over as a family. I had just moved and it was my kids and me. We had started a new chapter, and Max was an early birthday present for my son."
Meanwhile, Sheikh's kids are devastated.
"(They) miss him so much," she said. "I'm still holding on to hope. My family coworkers and friends are super supportive and have help raised reward money."
His absence is tangible. When Sheikh gets home from work, Max immediately makes her feel loved -- despite having him for only a few weeks. Without him, the house is quieter. There's a hole where he used to be, she said. The family is incomplete.
As of Tuesday, Sheikh said there haven't been any major leads on Max's whereabouts.