How can I stop my female lab x being aggressive to other females? She isnt like it with males she plays and flirts like a tart. But another bitch she tries to start a fight and has on one occaison got in a bad fight. Is there anything I can do. She was spayed 4 years ago. Short of putting a muzzle on her or never letting her off the lead I dont know what to do.

As she is aggressive and is 4yrs old I dont think there is much you can do about it now. As you say the only thing you can do is keep her on a lead and if she is unreliable even when on the lead and you go to busy public places I would muzzle her at these times.