So sorry you have lost your dog is such a traumatic way. It is very hard to lose a dog, and more and more support systems are being made available to grieving owners considering the extent of pain we feel. Lots of guilt and "what ifs" tend to run through our minds and that's a normal stage of grieving. You have no fault other than living in a place with such inconsiderate neighbors who leave their dogs at large despite a history of killing, but that's not a fault, it's just an unfortunate situation that you could have never predicted. Your dog was loved deeply, may all the good memories prevail in this difficult time. I wished there was a way to lessen the grief, but it seems like it comes in stages, and we must navigate the waves of sorrow. I truly believe that, out of all the lessons of unconditional love, the joy of living in the moment, and the noble art of forgiveness our dogs teach us, we must also learn to live our lives without them and be strong, focusing on considering ourselves honored to have met them. Sending you a virtual hug.