Shepherd isn't one breed but a label for dogs with herding or flock-guarding roots. On adoption listings it usually means a German Shepherd or a mix, though Australian, Belgian, Dutch and English Shepherds and crosses with Labs or Huskies turn up too. Their ancestors moved, gathered and protected livestock, which is why so many are alert, quick learners that like staying near their people.
Most are medium to large, roughly 45 to 90 pounds, with a thick shedding coat. Some are friendly with everyone, others reserved or protective with strangers, so calm introductions to busy sidewalks and visitors help. Herding instinct can show up as nipping or chasing bikes and cats. Plan on daily exercise, training and plenty of brushing, and expect each dog's personality to differ from the label.