Our dog Diesel

Question
Diesel our dog is an English Mastiff!  He is 2.5 yrs old.  He is a smart dag and good natured dog, until last spring someone tried to take him. They did get the his collar off but, was unable to get him in the car. Now when someone drives up it seems he is fine until they hold out there hands so as to let him get to know them and at first he is ok then all of a sudden he lounges at them and barks or growls. Some times they don't even have to reach for him,but most of the time it is when they reach out for him. We think it has something to do with them reaching out. It is getting serious and we are scared someone will get hurt. How can we break him of this and help him become the more laid back dog that we had? Is this a protective mode he is in?  Thank you for listening.

Answer
Hi Pamela,

The lunging behavior your dog does may or may be related to the attempted kidnapping event. In either case, it sounds like your dog has, what's called: territorial aggression. There are two primary motivations for territorial behavior: dominance or fear/anxiety.

When dogs display aggression to strangers only on the home property (in the car, which the dog sees as "his"), and do not respond aggressively to strangers on neutral territory, territorial aggression is the likely diagnosis. Almost anything that allows a dog to identify a territorial boundary really can contribute to aggressive behavior in a dog who leans towards territorial defensiveness.

Dominant dogs have a responsibility to warn other pack members of a stranger's approach and they do this with confidence and authority. Dogs that are overly dominant, both in absolute terms and with respect to their human family members, may provide a serious obstacle for any visitors to the home territory. Where owners have some control, they can usually reassure the dog that the person is, in fact, welcome, at which point the dog will settle down. In most cases, once a stranger has been welcomed inside the home, the dominant-territorial dog will relax and enjoy the visitor's company.

In a way, the only distinguishing feature between territorial fear aggression and overt fear aggression is the level of confidence that the dogs possess. Fear aggressive dogs generally have enough confidence to be aggressive to strangers on or off their own territory. Territorial/fear aggressive dogs have a lower level of confidence that permits the expression of fear aggression only on the home territory or from within the safety of the owner's vehicle.

You should keep doors or gates secured to ensure that no one enters your property without warning. Your dog may well bite somebody one day. Until you can get control over this, your dog should wear a muzzle. A wire basket style muzzle is the most humane, it allows the dog to allows the dog to pant, drink and accept small treats, but prevents biting.

You should have your dog evaluated by a dog behaviorist, so you can pin point the kind of territorial aggression your dog is displaying (dominance or fear/anxiety based). Treatment will vary depending on the kind of aggression your dog has. You may be able to get a recommendation for a dog behaviorist from your vet's office, or boarding kennel. To find one in the yellow pages, look under dog obedience schools.

You can read more about aggression in dogs, here:

http://www.dog-health-guide.org/dog-aggression-behavior.html

http://www.natural-pet-care.com/natural-pet-health-blog/horses-and-ponies/unders...

Best of luck,

Patti