Please Explain: Dogs

This week's Please Explain is all about dogs. We'll find out the evolutionary roots of domestic dogs, what it means when your dog wags its tail, and why some breeds are easier to train than others. Veterinarian Dr. John Ciribassi, who was one of the editors of Decoding Your Dog, and pet expert and journalist Steve Dale, who contributed to the book, take your calls and questions about man's best friend.