Help?! My dog is a bit obsessive over her chewy bone/whatever she has in her mouth?

what u need to do is let ur dog know that u own all toys. the thing u must do is take the thing ur dog is most obsessed about and take that before dog gets it. put the toy on the floor and if ur dog goes to it, block her. just stand and and move so u dont let her go to it.after few tries ur dog will give up and just turn around or sit, and if u give her the toy at that moment she will not want it. i have seen many of theses cases work out that way.try it, u will see.u r dominant one and she will only play with the toys U give her. its not HER toys, its all yours and u share with her.