"I don't have any kids so she kind of is my child really. At this time of year it's just craziness."
Police are investigating the theft.
Ms Macdonald said Mana was a sweet-natured dog, with a shiny black coat, white chest and white left toe.
She is offering a "healthy reward" for Mana's return.
"All I want is my baby back, no questions asked," she said.
The car is a 1999 white Toyota Carolla station wagon, license plate BCH683.
Macdonald has been a fashion editor and stylist for nearly two decades and was the contributing fashion editor for the Herald's Viva section.
Anyone with information can call Ana on 0275 273 729 or North Shore police station on (09) 477 5000