With tough breeds of dog it can also lead to abuse as frustrated dog owners mete out increasingly severe punishments to try and bend the dog to their will (thehappypuppysite.com)
Dalmatians are a reasonably tough breed to look after properly. (pawster.com)
The Malamute is a physically tough breed with enormous strength that can easily knock over a child during play or drag its owner around the neighborhood unless it is properly trained and has learned its own strength. (iamra.org)