Suddenly aggressive 4 year old
Sorry in advance for the long read -
My GSD Jager has been with us since 9 weeks old. He is coming up on 4 years now, and within the past three months has been showing signs of aggression.
For the past year, he has lived with my grandmother while my husband was in the military, as he was not allowed in our housing. We just recently got him back. He was not well socialized or exercised during this period (not the best situation obviously, but the only way we could keep him) but it did not seem to effect his personality. I visited him every other month throughout the year, and the changes just occurred within these past three months.
He was also neutered recently, although I'm not sure that plays a part in aggression. I haven't personally ever heard of a dog being more aggressive after being altered.
I'm very confused as this is a dog that just a year ago was going on off leash hikes and beach trips, dog parks, out in public everywhere, without a hitch.
He would occasionally show slight aggression (low, calm growls) to strange males (I am a female), but never to the extent he does now. Prior to recently, any aggression would be instantly curbed by me shaking hands or hugging the approaching male. It was my way of telling him "this person is not a threat" and he understood and could then be handled by the stranger.
He now will lunge, growl, and bark at strangers and dogs in any environment - whether in his home or out on walks. He is his normal, friendly self to our friends and family that he has known long term. He is also fine with our 7 month old dutch shepherd that we adopted during our absence (he had lived with her for a month during our last visit).
Our latest home visitor was able to win his trust over with some food; he growled and lunged when he initially came in, but after a couple of treats was fine with him being around.
Does it sound like I need a behavioralist? I'm wondering if these issues will settle down, and he is just readjusting to me being around. I am very much "his person" and I'm wondering if he's just being extra protective of me after being gone for so long. We've only had him back for a week.
If so, does anyone have any tips for choosing a great behavioralist? I've never so much as had to take him to an obedience class so I'm at a loss of who I should pick. I don't want to hire the wrong trainer and have him regress even further.
I, eventually, want him to be back to his old self so we can continue bringing him with us as many places as possible.