DOGS will remain loyal to their masters for life. When a dog sees that someone loves, cares for, and protects them, they become entirely loyal to that person. Also, by nature dogs are considered pack animals, meaning that when in the wild, they roll in groups or families of dogs to find food and stay safe. So a pet dog might consider the humans he lives with as part of his pack or family. They stay completely loyal to their pack and will defend if someone or something threatens their family members.