MISSING Brindle-colored chihuahua (redwood city)

Our small chihuahua mix who is dark brown with black markings/stripes is missing. He has a white muzzle, is neutered and has a mole on his left cheek above his mouth. He was lost in San Francisco and we believe that he was picked up by a young woman and then given away. If you know of or see a small chihuahua mix that resembles him, please call or text. Thank you.