Complex sentence: Welsh Terriers get along well with older children; they love to play and follow a child as it plays, however, they will often tug at pant legs of young and old people and can knock young ones off their feet.
Split into simpler sentences: Welsh Terriers get along well with older children; they love to play and to follow a child as it plays. However, they will often tug at pant legs of young and old and in doing so will knock young ones off their feet.