Marnalou,
I really like the muzzle idea - Stewie should still be able to go out and play, and since he's such a large dog, I don't think any other dog would attack him. I sure hope this works, and I want to encourage you guys to follow through - after all you need Stewie, not the Hound of the Baskervilles!
P.S. I'm sure the idea has alrady occured to you,
but in case it hasn't, you might want to invest in a second muzzle - George can use it....
Marty (boy oh boy, I can't wait to hear his reaction to this!)

Marty