I am sorry to here this! It is the way the small cruel few treat dogs badly that make them dangerous. I'd say the poor girl was treated badly before you got her, and as for your neighour nadine, some poison in their water probably wouldn't go astray!
Im sorry to hear about this alasse. For both your family and Tigger Doo. You try and do the right thing and reverse the damage someone else has caused only to be the one who has to deal with the sadness involved with an ending like this.
Ive said it before and I will say it again - when will the laws regarding pet ownership catch up to the real world. Eye for an eye - give the original owners of poor Tigger Doo a little of what they gave her and see if they do it again ....
That is so terrible, it can be really tough when you have to make a decision between doing the right thing and keeping someone who you love. My pup was abused too and now hates strangers and can get very aggressive but is meek as a lamb with us, but that doesn't mean that one day she won't snap. It's a very scary concept. I wish you all the best and I hope that you feel better soon and know that you gave her a good home whilst you had her.