He's in another place, yet he's close to you. If you are aware, his energy will show up. Several years back, I lost a shepherd mix, who I loved dearly, who had went to college with me, saw me get married, have a baby and so much more....the day she passed at 14 years old, a dust devil of leaves traveled for a ways when it landed right at my feet. It was about her same height, and yes the story is much better in person but I can tell you that it was her. I know it. My hair stood on end with goose bumps...I will never forget.
Another dog we lost just this last Spring who was coming up on 13 years, went into the vets and I insisted on pred and antibiotics. To make a long story short, they only teated him with the antibiotics, the pred would have acted as an anti-inflammatory in short he died from complications, basically swellings, he was in pain and went quickly. The vet toward the end agreed with me that he needed to go on the pred. but it was too late, one tablet later and he died with me and my daughter at his side. He was always by our side and friends with the first dog I mentioned.
We sat that night talking by his lifeless body until the early am hours, his coat amazing, soft and puppy like. It was his gift, I told my daughter. The next morning, as we were exhausted and drained from tears, we went together to set him free. Both my daughter and I heard him take a sigh, like he always did when he was sleeping....he was not alive but we could still feel his presence...it was quite special really...in his final resting spot we planted three aloe vera. I have had these plants for many years...not until now, have they bloomed big orange flowers! It is another sign...I also believe, he pointed us to Starla my GSD puppy. This was confirmed by the third afternoon she was with us, I watched her trot on over to his grave, pick up his collar with his name tag and bring it to the front door and set it down!
Life has an amazing way of perpetuating. You are right, there is something about a GSD, I am experiencing it right now with a purebred. But your other dogs are by your side for a reason, they miss him too...and if you tune in to the signs you might just discover he is still with you