Properly bred, socialized, and trained, these dogs can be model citizens. But as a result of inbreeding and overbreeding to meet rising demand, many are showing up with extreme forms of aggression and fearfulness, which some owners encourage with abusive training and rough play. Poor breeding practices have also produced lines of show dogs with extreme dominance aggression, primarily English springer spaniels, cocker spaniels, bull terriers, and golden retrievers. Dogs with this condition, called rage syndrome and associated with epilepsy by some researchers, albeit without hard evidence, attack their owners without apparent provocation or warning. Aggression, whether it is expressed through territorial defense, possessiveness around food or toys, fighting with other dogs, predation, or attempts to dominate members of the human family, is the problem behaviorists are most frequently asked to treat.
Many dogs are aggressive out of fear.
Anxiety and phobias are the next most common. Sometimes the conditions are knotted together. She urges owners to seek assistance at the first sign of unusual or threatening behavior. After addressing any physical causes, the therapist designs a program to modify the problem behavior and to teach owners and their dogs the cues and rules that will make living together more bearable. The program may include counterconditioning and desensitization to stimuli that frighten or arouse the dog.