10 month old out of character aggression towards strangers

[porcelanne]

I have a beautiful kind hearted gentle soul white gsd Nanook. He is my baby boy and my life. My fiance works half the year and so is home for a month every two months. I work full time shift work and lately every time I come home my fiance tells me our puppy (who is a BIG dog already - 45kg, 27" tall male) displayed a lot of aggression towards one of the neighbours who came to the house, or the postman.

Every time I hear this I have taken it on board but pretty much ignored it down to people not being able to handle dogs very well and so blaming the people, not my dog. However I was home today and went out to meet the postman in our garden with the dog.

My dog then jumped up on the fence but was scarily aggressive. If he was not my own dog I would have been terrified!! He grabbed the mail and could have bitten the postman's hand! This behaviour is unacceptable and a little embarassing as my dog is a reflection of me. I am appalled to see him behaving this way! He is very good with all people, has never been destructive, he has always been really chilled out as a puppy. He's great with my step-daughter who is four and smaller than he is! So why this barking when people are outside and aggression at anyone who comes near our fence or gate?

Is it him being overly protective of our land? I NEED to stamp this behaviour out now.

Does anyone know if this is an age thing? Or a lack of training? He is very well trained and always very obedient to me. So to see him behave this way is shocking!! Do you think he is scared?

Any help, advice or if you've experienced something similar at this age of development would be great to hear about.

Thanks!!

Here's a picture of Nanook. He is a big boy but still a cute baby. I took this photo yesterday...

[Mary Beth]

Nonook, what a handsome devil and acting like one too! Okay - he can't get by with this, and my Sting would have done the same only a 6 ft. chain link fence stopped him. What it takes is work and also discretion on your part- I put Sting on his leash and I started inside first, when the mailman came - and Sting went into his big act - I jerked him off the sofa and made him sit and be quiet - I stood in front of the door to show I owned it and I could control who came in - when he was quiet - I opened the door and got the mail - Sting had to hold his sit/stay - he got to sniff the mail and got a treat. Then I practiced outside in the backyard with Sting on his leash - when the mailman came - Sting had to heel and follow me around the backyard - he had to sit/stay -he was not allowed to bark or lunge. I then walked him on the sidewalk first when the mailtruck was down the block - then on the opposite side of the street when the mailtruck was at my house. He is trained now to be quiet when the mailman comes -he can give one little warning woof, but that is it. So, if you want to meet the mailman with your dog, you will need to have him on heel and do a sit/stay. Also if your mailman has treats which mine does - that explains the grabbing - so I avoid such incidents and don't greet the mailman with my Sting.

[porcelanne]

Originally Posted by Mary Beth

Nonook, what a handsome devil and acting like one too! Okay - he can't get by with this, and my Sting would have done the same only a 6 ft. chain link fence stopped him. What it takes is work and also discretion on your part- I put Sting on his leash and I started inside first, when the mailman came - and Sting went into his big act - I jerked him off the sofa and made him sit and be quiet - I stood in front of the door to show I owned it and I could control who came in - when he was quiet - I opened the door and got the mail - Sting had to hold his sit/stay - he got to sniff the mail and got a treat. Then I practiced outside in the backyard with Sting on his leash - when the mailman came - Sting had to heel and follow me around the backyard - he had to sit/stay -he was not allowed to bark or lunge. I then walked him on the sidewalk first when the mailtruck was down the block - then on the opposite side of the street when the mailtruck was at my house. He is trained now to be quiet when the mailman comes -he can give one little warning woof, but that is it. So, if you want to meet the mailman with your dog, you will need to have him on heel and do a sit/stay. Also if your mailman has treats which mine does - that explains the grabbing - so I avoid such incidents and don't greet the mailman with my Sting.

All sounds great! I am definitely going to try this. I know how he'll best respond from training we've already done so we'll just go from there. Thanks for all the advice, very very helpful much appreciated!! Will start indoors first today.