Aggressive/Territorial

[BOBS DAD]

I know you are going to get a lot of dog whisperer advice on this one...
but the problem is not new. HE'S A DOBERMAN PINSCHER!

Lovable dogs and beautiful, but extremely terrirorial. I know... I have been chased my many in my day. LOL! My ol' neighborhood was one of punks and hoods (today's gangstas), and they just loved their DPs. Always let them wander loose around their cribs (home's to you non gangsta type peeps) and you could not get within 200 feet of the house before being attacked. NOW I KNOW THAT EVERYONE IS GONNA SAY HOW LOVABLE AND FRIENDLY THEY ARE but...

If they were so inheritantly friendly, why do they make such good watch and guard dogs!!!??? When I wanted a small dog that I could take with me into the fields and walk while he/she hunted - I got myself a Beagle. Because it was inherently likely he/she would do this. If I had a warehouse to protect, a Beagle would likely lick any intruders and wag his tail while they emptied the place out.

Of course, there will be some things you can do to minimize this aggression - like make sure that all and any of your friends/family/associates who are coming to your house on an "expected" visit, bring with them your Doby's favorite treat. And the first thing they do when he greets them is to offer the treat. This way he will begin to associate visitors with "treats" YEAH... Yup.. YUP... "I am sooo happy you are here"!!!! LOL! This will also reinforce that it is Ok to greet people in a friendly manner (while you are present) and not turn him into the "Beagle" that greets everyone with a wag - whether you are there or not - whether they have treats or a gun!!!

But this will all be a very slow, gradual transition in behavior, with a lot of work and reassuring on your part - "as it is not natural" to his disposition. I know you are going to get many, many others who are going to say "something "bad" must have happened to trigger this switch, but I say no - he just got older and is maturing into the dog he was meant to be!!!

[Dixieland Dancer]

For the most part, I agree with what Bob's dad said. I do not think something triggered this behavior as much as it is just the dog maturing. Even the AKC recognizes the temperment of the breed and will immediately disqualify the dog for out and out viciousness but recognizes an aggressive and belligerent attitude as acceptable without being disqualified....

From the AKC site....
Viciousness: A dog that attacks or attempts to attack either the judge or its handler, is definitely vicious. An aggressive or belligerent attitude towards other dogs shall not be deemed viciousness.

Before someone says something in defense of the dog, let me be first. I think these dogs are very out going and loving and definitely smart and obedient (obedient being the operative word here)! They require a strong handler with clear objectives set in the training exercises. Training should be on going and not stop at the end of socialization or basic obedience. When someone comes to the house, the dog should be put in a firm and unquestioned down position so that he understands you make the decisions on who comes into the house and not him. Never use harsh punishment with this breed (or any breed in my opinion), only positive reinforcement. Using harsh punishment could defeat the purpose and make the dog more aggessive / territorial.

Dobes respond great to clicker training and are quick learners so my advice would be to get him back into training with a qualified instructor who uses positive training, preferrably clicker training and never give him anything unless he works for it first. You should start to see improvement soon.

However, at some point you are going to have to do specific desensitizing exercises for people coming to your house since this is the main problem. Ask someone not close to you but not afraid of your dog either to help out. This should not be done though until your dog has a firm and reliable down stay.

[DrKym]

Ok this is going to be long winded also,

Yes Dobes make great watchdogs, so do Poodles no joke. Dobes will and do like all dogs read your body language, you stated you put a deathgrip on his collar and leash when passing, I reccommend you dont do that instead put him in a sit and let them pass, reward him for his gentlemanly behaviour.
Also teaching him to sit when you answer the door and to stay sitting will defuse his lunge response. You didn't state if he growls or bares his teeth or is showing true aggression or just a response that hasn't been redirected. I raised rotties for 23 yrs and my parents raised danes, gramma had dobes, so I am only speaking from our experience, I had a rottie that did the same thing (female) and never realized that I was feeding the response by reacting to it, these breeds need a firm hand and a no nonsense attitude as to who is alpha, and what is expected of them. Try not to tense when he does, put him in a sit and retrain him to ignore the stimulation, it wont take long and he will be a perfect gentleman, they desire to please. As for not knowing if they have a treat or a gun? the more socialization a dog has meeting 9999 great ppl gives them the ability to know when that 1 is "off' somehow, because dobes have a natural guarding instinct your job as his alpha is to not encourage it, if it was ever necessary to protect you from an actual threat he will without hesitation and without any additional training.