PATERSON, N.J. (CBSNewYork) — A beloved dog is missing in New Jersey. Officials believe there may be more to it and now, his young owner needs his best friend more than ever.

Coming home from school just isn’t the same for Jacob Rodriguez after his seven-month-old Shih Tzu named Brownie disappeared from his Paterson backyard on Saturday.

“He’s my best friend,” he told CBS2’s John Dias.

In November, a family friend gave Brownie as a gift to the seven-year-old. Ever since, the two have been inseparable.

“I miss sleeping with him,” the heartbroken boy said.

Jacob suffers from muscular dystrophy, and in just two weeks will undergo a major surgery. Brownie was supposed to boost his mood.

“He’s been very happy since the dog has been here,” Jacob’s mom, Jazmine Crespo, said. “He just loves it because he hardly walks much, so he’s been all over the place with the dog, all over the floor.”

Jazmine says the dog went missing when she was out getting chemotherapy for lupus. Her oldest son let Brownie outside or just a minute in their gated yard, but the pup vanished.

“He’s done this before,” she said, “but he’d be right here on the front porch, scratching.”

Paterson Animal Control say they have an idea of what happened.

“Someone out there has it,” Chief John DeCando said. “Someone knows where it is and I’m pleading to them.”

DeCando believes someone stole the dog out of their yard, or kept it after finding Brownie on the street — which is illegal in New Jersey.

“It’s called theft of movable property,” he said. “You can’t take a dog off the street and keep it. It’s not your dog.”

No matter the case, Jacob has a simple message he wants everyone to hear.

“Give Brownie back,” he pleaded.

Animal control has also reached out to other local animal shelters to spread the word. In the meantime, a $500 reward has been offered.