One, Dee does not really know how to play, and when other dogs are playing she will break it up and be pretty snotty. She doesn't do that with the dogs in her family, she goes and gets her bunny bear (a stuffed toy) and chews on it and stays out of the Rowley/Beau/Alex rough-housing; but a week ago at Manners class she waded into a play session between Alex and Bertie (another Lapphund) and put Bertie down. I didn't like that, and what I liked even less was that the next time Alex saw Bertie, and Bertie invited him to play, ALEX put Bertie on the ground, borrowing Dee's bullying behavior even with Dee not there.
That's not going to happen again, I really don't like dogs who act like jerks, and when my dogs do it, I need to fix it.

But, the muzzle: last weekend at the fields by the Ag HS, where people run off-leash dogs, we met a dog -- he was probably Lab/Pit mix, or predominantly so -- who was bopping around with a muzzle on. A nylon muzzle, not tight enough to interfere with his breathing or sniffing, but a muzzle. I said to his owner, a woman in her 40s, 'so, what's up with the muzzle?' and she replied, cheerfully, 'oh, he's been a jerk to a lot of dogs and I just don't take any chances anymore. People were starting to leave when they saw us here.' My dogs and I walked with her and her muzzled dog, and were joined by several other people and their dogs, for about half an hour. (Again, this is an off-leash group, an informal dog park.) The muzzled dog seemed to be having a good time: he did some posturing, but nothing more, and no other dog engaged with him beyond a casual greeting. Alex play-bowed to him and they ran a bit, but by and large the muzzled dog was just chilling with the pack of humans and dogs.
Now, I don't know what that dog did to earn himself a muzzle, but it started me thinking and wondering why muzzles seem to be out of favor now. I get that they might be a way to bypass behavior modification training, but what if they're just reasonable reactions to behavior that can't be changed? Not everything can be fixed, and with rescue dogs that have who-knows-what in their history, maybe it's kinder and simpler to just say 'okay, you wear a muzzle and you can still go on outings' and the dog adjusts.
I doubt that a muzzle is indicated for Dee -- she simply won't be off leash around other dogs playing, that's on me -- but I'm certain that I will never be able to change her behavior toward other playing dogs. Something occurred in the first 16 weeks of her life, I would bet money, that gave rise to this behavior in her. Perhaps she lost her littermates or her mother. Dunno. And I'm happy that she doesn't go after the dogs in her family. But if I were to put a muzzle on her, would that be a failure on my part?
Would you ever muzzle a dog for behavioral reasons? Just curious!