Oops, just realised this thread is quite old, sorry!

Red

I think on lead dogs SHOULD be muzzled if DA, leads are NOT infalbbable. Leads can and do break. Collars can and do snap. Humans can (accidently) and do (accidently) let go ofleads.

Or you could get approached by a guide dog...

my boy's been attacked by 2 dogs of late off lead, one was quite nasty attack and still the damn things walked off lead.

I have a DA dog - not all dogs, only large black male, or dark coloured dogs, he's fine with all small dogs and all females.

When we are walking Ben in an enclosed area, like a wood, we have him muzzled and on the extending lead. When walking round the flat fields where we can see for a long distance, we have him loose but carry the muzzle. If we espy a dog in the distance, he is instantly recalled and the muzzle put on. He is then put on the long lead as well if needs be. Now his recall is 100%, we find this is best practice. If the approaching dog is male and dark coloured, Ben will sometimes react even muzzled and on the lead, so therefore the muzzle and lead stay on until the end of the walk. He is such an intelligent dog that he has learned now to remain calm, although we still would not trust him, and yesterday even when we walked past a small black male just about large enough for him to consider a target, and he was off lead and unmuzzled but right by my side so I could grab his collar, he completely ignored the dog (who was barking at him) and calmly walked by my side, as did Tai. We are getting there ...

but I am a huge fan of muzzles and if need's be when on the lead as well.

No I don't see the need to muzzle so long as the dog is on lead and under control. My Bichon has fear aggression so I keep her on a lead at all times and when a dog off lead charges at her I pick her up. I think the responsibility falls on those with their dogs off lead and uncontrolled where by law they shouldn't be.

I would always muzzle. My DA GSD has gone for a dog once, when I'd had her a few weeks and didn't know what she was like with strange dogs. She slipped her collar, my fault. I don't ever want anything like that to happen again so she is muzzled (and her collar is secure). I often walk her in the very early hours of the morning (1-2am) and might remove the muzzle then as it's highly unlikely we'll come across another dog, but I always have it on me, and she is always on lead. If I do let her off the lead for a bit (again, only very very early in the morning), the muzzle is always on, just in case.
If you know your dog is aggressive it is the responsible thing to do to muzzle them imo. Like it or not other dogs will approach at some point and I wouldn't want them hurt. It could be someone's puppy, who 'just wants to say hello' - yes, I know, but I remember when my pup was like that and I wouldn't have wanted him bitten or mauled because someone didn't muzzle their aggressive dog.

I think yes. When Max first started showing signs of agresssion, i thought it would be ok.. But there is always that chance of an accident or getting caught by surprise. When Max ever got hold of another dog, he just hung on to kill! There was no way that i could take that chance. I used to take him out at 4am in the mornings, without a muzzle. That was the only time.. as we never saw anybody. His day walk was always with muzzle on.

I thought yes as we had a lot of fools around here who let their dogs off lead run up to Chase and he snaps if they get in his face (never once has he bitten) however, on a recent walk with both dogs we were in the woods we tried muzzling Chase and as we rounded a corner there was a group of people we had taken Chase's muzzle off to play in the water with Storm, there was an off lead dog who came bounding to us, we shouted to the owner to call the dog, she replied "I can't he won't come back now he's seen your dogs" (I kid you not) with that the dog launched at Storm and went straight for the throat, then started jumping to get to Chase, both of my boys were able to defend themselves, no one was bitten through the skin but had Chase had been muzzled there isn't a shadow of doubt in my mind that he would have been badly bitten by that dog. The owner didn't even bother to apologise! We were livid! So no, now I don't believe in muzzling on lead controlled dogs, off lead aggressive dogs is another matter.

this discussion always goes:

1) No My dog is on a lead and under control so what ever happens is someone else's fault.

2) No - If my dog was attacked he couldn't defend himself.

3) Depends how aggressive your dog is.

I'm with number 3 - simply because there's been 2 dogs in the family that would attempt to kill a rude interloper. Peace of mind.