Hi i am about to breed my bitch and have looked at when she needs this vax as i was going to use it but really dont know now, I keep hearing different stories.  Can I have someone else opinion please :)

There was a recent discussion here - http://www.champdogsforum.co.uk/board/topic/130872.html

Might help you :-)  Personally, I have used it twice on the same bitch whose mum had been problematic when mated (missed time and again despite being mated on any number of days and to a variety of males).  Eventually I got her in whelp with the help of Premate and I got the one girl (plus two boys) I was hoping for.  Daughter has produced two super litters with no problems at all.  OK, she might have done that anyway but I thought I would try it.  I only wish it had been in more widespread use when the old girl was of breeding age.  I would always consider using it if I thought there was the need.