I hope you make a complaint with the local police department and animal control. That dobie sounds like a menace. Biters need to be recorded as such. In our county, there's a three-strike law. Three bites and you're out. Imagine if the dobie gets ahold of a small child.

ETA: I'm so sorry this happened to your pooch. Such a cutie! Even with an Elizabethan collar and a sad, sad look...