what should i do for the best

hi all
i would like some advise please i have a springer bitch whos nearly 7. shes a people dog ive had her since she was a pup (also have 3 other dogs incl bt pup) the trouble is when i take her out to the forest shell see another dog go bouning over bend as they do to play then roll over to her back then get up and start showing her teeth and barking at the other dog. shes never bitten another dog (she does this at homesometimes when the pups playing with the other springer but i just have to look at her and she stops.
the thing is i apologise to the other owners and she comes back to me but the seem to think shes aggressive. could this be nervous aggression. i know she hasnt bitten another dog but do you think i should muzzle her on walks now. when i see another dog now i call her straight back to me either put a lead on her or she waits with me til they have passed then just goes off and runs ingnoring them. any advise would be gratly accepted

why not carry on doing this if she comes straight back?

the trouble is shes already started barking and showing her teeth cos she doesnt do it all the time i keep an eye on her but cant always tell the signs she gonna do this i dont want to muzzle her and i do try to walk where although you can see other dogs its so vast she dosent always see them.

Thats abit confusing...rolling over on the back is submission, so is this her trying to see if the other dog is dominant and if it's not she then takes dominance or do they sniff her private partsand she turns. Because I used to own a Bc that was fine until another dog sniffed there, then she would show her teeth. I think I'd just keep calling her back B4 the situation and allow the other dog to approach to see if behaviour is the same, then if it is obviously you will just have to keep calling her back

Is she with the other dogs when she does this? My GSD is fine with other dogs but if I go out with a friends `pack` she assumes the role of Pack Protector and gets very upset if other dogs come up. It sounds like you have excellent control and she`s never bitten so I wouldn`t get too bothered about it - maybe she`s just warning the others off.

thanks for all your replies shes usually out with her own pack but shell go to other dogs on her own the others arent interested . i wouldnt say she thinks she head of the pack as she waits to see what other springer does then follows him but if he goes off she wont come back to me she waits for him to return then tells him off by grabbing his neck . i think ill carry on walking and calling her back when another dog approches or put her on the lead its not the other dogs they want to carry on playying its the owners who are worried but i dont want to spoil their walk cos of my dog.

My dog was attacked by a spaniel and is now quite nervous of dogs that run up and bark at him. It is worth thinking about the effect this behaviour may have on the other dogs. I would not appreciate it to be honest. I am not being awful but it could cause problems for the other dogs in some circumstances.

i understand heidi but shes never attacked another dog just baked and showed teeth but i do understand dogs can be nervous so ill keep her on a lead when i see another dog