Sasha was probably a part of a dog fighting ring causing her not to trust other dogs. It's so sad that people feel a need to subject animals to this kind of abuse!
I've had two of my pets euthanized,(a dog and a cat) both were excruciatingly painful, like someone is ripping your heart out! They were both so good and loving as only a pet can be! I miss them both, and cry every time I think of the loss! I'm sure Sasha knew you were there, and that your love for her was real and deep! I'm super sorry that you had to experience this awful situation! Take care!