Miniature Dachshunds Queenie and Roxy were stolen from a house near Knaresborough in August and a number of appeals have been made to trace them.
In a key development, on Tuesday last week, West Yorkshire Police received several calls from members of the public reporting two Dachshunds had been abandoned on the A1 motorway between junctions 41 and 42 in the Knottingley area.
The dogs were left by the occupants of a blue Volkswagen Golf. It is reported a woman driving a red car stopped to try to help the dogs - one of whom is on urgently needed medication.
Contact North Yorkshire Police on 101, select option 2 and ask for Cheryl Power.