Does anyone know what the magical number is regarding when to mate their bitch?  A friends dog was tested by Idexx yesterday and it came back as 4 - and re-test 2/3 days which is of course over the weekend.  She was day 13 when tested.

Ideally low 20s upto the 60 mark.

What I would do is if she starts standing get her mated then send off the blood and see if
she has ovulated.
My parents bitch once ovulated very fast and if we hadnt of done the mating we would of missed her.

Brilliant - thank you.  I've suggested to her that she take her to stud dog on Sunday to see if he's interested at all and do bloods again on Monday.  I've heard the levels double every 24hours or so - do you know if that's true?

When you get nearer  e.g 15. Add half that figure which = 22.5 for the next day. Then half again e.g 11, and add again which = 33.5. So then you are in 'the window'.

Thanks for this info - bitch was mated yesterday and again today with sucess so I don't think they're going to bother again with bloods.  Trying again tomorrow to see if he's still interested!
My own bitch has been tested today so this will also give me much more idea of timings.