How frightening. I'm glad the damage wasn't too major. I agree with everyone else--you did what you had to break them up. I've had a couple fights here where I am not proud of what I did to break it up, but gentler methods had already failed.

My Kayleigh has a similar issue. She was starved by her first owner and is highly food aggressive. I don't believe the behavior of protecting her food can be changed any further. Kayleigh is like your dog--she would let me take her food, but doG forbid another dog tried it. Kayleigh has some generalized dog aggression issues too.

This is what we do--Kayleigh has her own pen. She can see the other dogs and verbalize with them. The dogs she gets along with, mainly Heyoka, are let into her pen daily to play with her. I go in first and pick up her treasures, just in case she wanted to protect them! Kayleigh gets taken for walks regularly with her buddies. She gets lots of one-on-one walks too. She probably gets more alone time with me than the other dogs do due to her aggression issues. When no other dogs are loose, Kayleigh gets run of the big yard.

Kayleigh is on a Nothing in Life is Free program as well. She wants a treat, she sits. She wants a ear rub, she obeys a command first. She gets nothing good without listening. Nothing bad happens when she doesn't listen, she just gets ignored.

Kayleigh is a doll, I love her dearly, but she has issues. We considered all the same things you likely are--putting her down, rehoming her ect. But she's our baby girl, she's just a problem child! Her issues can be managed and so Arthur's. You have to be diligent and constantly aware of his issues though--it's your responsibility to him, your other dogs and others he may meet.

Feel free to PM me if you want too--Dog aggression is unfortunately something I have lots of experience with.