I have a GSD whom I got from my son when he moved and could not have her per association rules (they ban pits, rotts and GSDs). She's pretty much been with us since she was 8 wks old and they moved back to MI from TX anyhow and were living with us when they finally found a home to rent after a year of searching. Long story short, she is not of a temperament I would have picked in a litter of pups as she is quite submissive. Yet, I'm in total love and have spent a LOT of time training her to help me with my complex-PTSD which I'd tried in the past to train an SD for (washed out that prospect but she's still part of our family). That being, she goes everywhere with me. I have a total of 5 housedogs and, for the most part, they get along very well. However, Sadie is very jealous of my 13 yr old cavalier king Charles spaniel who is going blind and deaf now so gets special attention as well. I tried curbing this. I knew I failed the day she picked her up by the scruff and shook her. My former SD prospect (GSD mix) stopped her immediately so no real damage was done. I used to raise/train/show dogs so I have a lot of friends in the dog world. I sought help even from different trainers. What finally worked was my own instinct so wanted to share. Previously, I was trying to make sure everyone got equal attention. This was WRONG. They would push forward to get in the mix to get attention so I was inadvertently rewarding jealous behavior without realizing it. Now, I only give attention to the first dog *I CALL* over to me. If they approach me, it's quick pat maybe and then move on. I call them, they must do something as asked (even just sit) and then they get lovings and the others get ignored. Never scolded so I don't make the one getting attention out to be the bad guy but they are just plain ignored. I then walk away and then *maybe* call the other one to me and ask them to do something and repeat. Seems tedious but now we have more calmness. I also had to teach the GSD to wait in a chair by the door while the cavalier goes either in or out the door to potty. They are not allowed out together for obvious reasons. However, now that has also increased the calmness. I don't even have to tell her to get up in the chair. She's conceding to the older dog so now the older dog feels more in control and safer and doesn't hide anymore. Sadie has acted guilty ever since the incident and now can be found licking and grooming the cavalier quite often. Hoping my experience helps someone.