Hi!
My 2 year old G S P girl loves to play rough especially with boy dogs. She romps around, chases, plays with sticks and generally has Great fun! But then  only lately she becomes almost obsessed and really pins the play mate to the ground (even bigger dogs than herself!) She bits into their throat and growls.If I call her off she does almost immediately . BUT the other dog comes back for more of this treatment & it all starts again neither of them becomes worst for wear but I don't want this to become an aggression problem! Any Thoughts on this? 
Thanks Cheddar

It's hard to tell without witnessing her in action - but dog's play is often very vocal and so long as nobody comes off worse (ie needs vet treatment) or feel intimidated, and the other owner has no objections, just let your girl enjoy herself.........

Thanks Digger! I have followed your advice,your comments are appreciated and do seem to work, although I will keep a close eye on her still. Just interested as you have answered my questions before,what gender are you?                   Regards LIZ (cheddar)

Hi Liz - Digger was male - he was my first dog, and the one who got me involved in behaviour 22 years ago - but I am female ;)

Hi again Digger!
Thought as much from your words of wisdom! I am now signed in under 'cheddar' so I'll now keep actively informed with your postings. Bye for now.