Four different Rottweilers were used to portray the dog. Special non-toxic makeup was used. The dog's face was shaved in spots and a vegetable based bloody substance applied to the shaved areas.
The xenomorph in this movie is referred to as "the dragon" by the character Golic and this is repeated by Ripley when she asks to question him. Some fandom have dubbed this movie's xenomorph "the dragon" for that reason. In that sense, a dragon does die in this movie.
Newt is dead at the beginning, you see her briefly while they are reporting the deaths, there's also the scene in the morgue, and an autopsy of her body which can be disturbing to watch.