Small Black and Tan dog spotted

Small black with tan coloring; approx. 15-20 lbs.; no collar or tags; can't tell if male or female; young. This morning, I saw this dog on Cactus (near Jupiter), just sitting and looking over at Jupiter Rd. Then, this afternoon about 2:30, I saw it sitting on Rolling Rock at Walnut Hill, near the Summer Glen Apartment dumpster. Both times it looked rather forlorn and tired.