Lost & Found Dogs in Las vegas

He has no collar on at the moment and is a large breed with a white tip at his tail

He does not have a collar.

Ran away from home on July 4th due to being scared of fireworks , is very untrusting and very skittish around strangers . Was abused in the past and I heard about him 6 months ago and was able to get him out of that nightmare and have been working on building trust but he still is very much traumatized from whatever he went through . But he had started showing signs of trusting and then he got scared of the loud noises and he was gone . He wudnt hurt any one not aggressive at all just scared . I'm worried sick about him