So first, a disclaimer, being as we live in a litigious society. Neither my partner nor I are trainers and thus offer nothing by way of OFFICIAL information regarding corgis. We are, instead, providing one household's perspective of dealing with this breed.
Oh, and one cattle dog's perspective (such as we can discern) on living with corgis. Same for two cats.
And speaking of lawsuits, yesterday was our first day of using Gryffyn's muzzle. We've been working with her on what we've determined is leash aggression coupled with herding instinct. People or animals will appear on the walk, she will go berserk (leash aggression), which involves biting us to get us to let go of her (the herding), and we then attempt to isolate and calm her. This only happens on the walk--everywhere else she is a sweet and gentle pup.
This is particularly worrisome as she is VERY cute, and so people want to pet her EVEN THOUGH she is writhing and snarling. See picture:
A typical interaction will be: lovely young man walks up, Gryffyn leaps up, teeth baring, grabs the metal leash (she has bitten through two cloth ones), she flails her whole body around, we then isolate her while she flings her open mouth around trying to bite us to let her go--all the while the lovely young man watches and says "so can I pet her?"
Are you kidding me?
What we realized is that our fear of getting bit or her biting others has made us so tense at this point that we're feeding the situation. So the muzzle.
I had a hard time with the muzzle--I worried it was a sign of failure or oppression. But it's working out great. We got the plastic one recommended by Best Friends trainers, put peanut butter at the end of it (which makes her VERY popular with the other two dogs) and off we went. She still goes nuts with other dogs or people, but now we can proceed with the walk, normalizing the process, and not feeding the anxiety.
So I'm now a fan of the focused and productive use of a muzzle for training.