Fudge, a four-month-old miniature chihuahua, disappeared from her owner's home in Kilsyth on Wednesday morning and has not been seen since.

The pup was bought for Melinda Pride's mother as a companion while she underwent treatment for lung cancer, following her diagnosis just before Christmas.

"It was only last week Mum said 'if anything happened to Fudgey I don't know what I'd do; she's just my saviour'," Ms Pride said.

Fudge was an indoor dog but had been let outside to go to the toilet just before lunchtime on Wednesday.

"[Mum] had just walked in off the decking into the house when she heard Fudge scream three times," Ms Pride said.

"She went back out and that's when she saw the black bird fly away."

Ms Pride said the family had been concerned about a murder of crows that congregated in her mother's backyard and now suspected the worst.

"She didn't actually see him [the crow] carry Fudge, but Fudge is gone," she said.

Her mother Heather was left "an absolute mess" by the Fudge's disappearance, she said, but the family was holding out hope the dog would show up safe.

"We're just hoping she's been dropped in a safe spot and is still alive," she said.

The family was searching the surrounding area and asked people in the neighbourhood to keep an eye out for the dog.