Your tribute was so moving for me with lots of tears and overwhelming sadness for you and Luther. He obvioulsy had a great life and was very loved. I don't know what happened in his case, but would like to if it's not too painful for you. I'll be thinking of both of you, and I am so sorry!
Luther was purchased from a breeder by an ex I was living with. Already 13 weeks old, born and raised on a farm, and his mother was so aggressive we couldn't even see her.
Needless to say, he had EXTREME fear aggression - as a little puppy. To the point that we almost considered euthanizing then. I personally worked very hard with a trainer. Luther got better and better. When Luther was about a year old, my ex and I split. I didn't see Luther for roughly 6 months. I then heard my ex was trying to sell him for drug money. Knowing I was the only other person this dog liked, I bought him back.
As he got older he improved by leaps and bounds, but you can't FIX "broken". Still fear aggressive, still had separation anxiety. Stress colitis (SEVERE diarrhea with ANY stressful situation). So aggressive in strange situations I couldn't board him anywhere, none of my friends/family could watch him because of the diarrhea.
Then last march, I came home to find that he had killed one of my cats. I own a LOT of pets, I'm a certified vet tech, and he had NEVER shown aggression to ANY of my animals. My cats slept with him for YEARS. It seemed like ever since that, all his other problems got worse. His aggression got worse, more diarrhea, he started attacking my other animals. He flipped my rat cage and almost killed them.
Then, one week in July, he went after my favorite cat, almost killing him. I took him in to the vet, we started him on prozac. Of course, theoretically even if it helped, here was a 3.5 year old dog I was going to have to medicate for the rest of his life. I also vowed if he went after my animals like that again, I was done. At the same time, we were trying to go on vacation for 5 days, and I couldn't find anywhere to put Luther. My work offered to take him, but I did not want my coworkers to deal with the level of aggression he displayed. Basically, they would of had to leave him kenneled for the whole 5 days, and just hose the waste down a drain while he was still in there. Not fair to them or him.
5 days later, it seemed like the prozac WAS helping some, but at the same time it was making him pretty sedate, not something I wanted either. Then, he went after my cat again. DESTROYED my bedroom, huge hole in my mattress, any my poor cat up in the window covered in his own urine. It was at that point that I just "gave up".
I always said an aggressive dog is ok as long as the owner can handle it responsibly, and as long as said dog was at least ok in the household. Luther was now an aggressive dog that was no longer ok in the household.