Feeling really conflicted here...
So, our beloved dog of almost 13 years recently passed away. We decided we were ready to start looking for our next companion, and we found a dog we all fell in love with at a local shelter. He has been home with us almost a month now.
We thought he was a very sweet, loving, affectionate dog. He was always coming to us to be pet, and calmed down very quickly. We did, however, notice some red flag behavior when, for example, he was sleeping and someone would come in the room (usually moving their arms) he would jump up and bark (sometimes something like a throat bark not quite a growl) but immediately go back to sleep. It did not happen everytime, or even most of the time.
Then, he did this to my husband, but it got worse, he jumped up and barked, growled (no teeth but hackles raised) and it lasted a good 30 seconds. We all go nervous, called the shelter, and paid to have a trainer/behavior expert come out. We were thrown for a loop because normally he is the most docile, kind, calm dog we have ever met!
Turns out the behavior person feel very confident he was abused and that his behavior is somehow due to a trigger or number of triggers and is fear based. When the behavior person took out the training clicker, our dog went CRAZY and barked at this poor person for the next hour he was here, anytime he would so much as move his hand. We have never seen anything like that before! The trainer also said that all that sweet dog behavior we fell in love with was in fact fear based, nervousness, or submissive/calming behavior, not just a really nice dog
The puppy (around 8 months) is also very attatched to us, me in particular. He would sit by me the whole time the trainer person was here, and generally he is stuck to me like glue.
So now we are in a tough situation. We have children, and hopefully will have more in the future. We really don't want to give up on the dog, but don't want to put anyone in a potentially dangerous situation. Knowing the dog is continually stressed and nervous makes us sad, and thinking about bringing him back breaks our hearts because we know he trusts us now. I don't know what the right answer is. Can someone with more experience/knowledge offer some advise?