It happened last month after police say Juan Carlos Chavez of Los Gatos answered a posting on eBay.
Officials say he say he met the sellers on the 700 block of Story Rd. in San Jose and asked if he could hold Bronxie, their 9-week-old Pomeranian. Then instead of paying, he pulled a gun on them and demanded their car.
The sellers jumped in their car quickly and drove off. Police say Chavez left with the dog.
Anyone with information about the case is urged to contact the San Jose Police Department's Robbery Investigations Unit at (408) 277-4166. Those wishing to remain anonymous can contact Silicon Valley Crime Stoppers at (408) 947-7867.