I have a female German shepherd that is 10 years old. And she is very protective as well, She bit her first person when she was 6 months old. And has bitten a total of 5 other family friends that they thought they would be fine with her even after being warned. Great watch dogs tho good luck man.

P.S. My german shepherd does not like my GF either, Only the people that shes known since she was a pup.

 

sounds like it needs attention. it's a work dog. give it a job! i have a work dog. if i dont work him out he bugs the hell out of me and becomes destructive. throw a weight pack on him and make him pull you behind a bicycle (my lazy way to work my dog). swimming also takes it out of him. swimming is great exercise for large breed dogs.

no dog is too old to learn...they just get harder to train. especially when they "have their role" for 5 years. the best way to teach is when they are young. i have a "big scarry dog" he learned really young that I am the protector and boss. he gets anxious and barks at company, but thats only because he wants to play lol. anyone that doesnt know him gets a little freaked out. i dont have a solicitation problem lol. they ring, see him and walk away.

 

He has alot of energy, and he needs(and wants) to work. That's the only way to calm him. I don't mean find ways to make him tired. I mean find activities to do with him that gain him attention, praise, & reward. A ball or a frisbee in a field, as an example. Teach him how to play & be rewarded for it, and he will change.

 

No, just some of us.