"Diego is not good with other dogs. On walks, if allowed to approach another dog, he likely will try to attack the dog, and may bite you in the process.
He is also possessive aggressive. He doesn't like toys much, but if he somehow gets into something with blood (i.e. bloody tissue), you must lure him from the item with a dog treat and not try to take the item away from him or you will get bitten. If he is asleep, you must not startle him, or try to force him physically out of his sleeping position. On the other hand, he's also VERY lovable. He is well trained in that he will never ever go to the bathroom inside, and knows many commands (sit, lie down, paw, other paw, stay, go to your mat, go to bed, hop…yes hop!). My wife and I have thoroughly enjoyed his company and HATE to let him go."
This doesn't sound like a dog that deserves to be put down-- it sounds like one who needs to be rehomed in the right kind of environment. Many Bs are leash-aggressive with other dogs. Homes with young children can be hard on Bs, and this boy may not be getting enough exercise and attention. I wish I could take him. Sounds like he needs a change of scenery and a chance.