I have a woman, who is a vet, bring me a bitch for my boy. I told her to get progesterones and bring her down after hitting 5 ng. She did her tests and says that her lab does serial progesterones and brought her to me today after hitting 1.6 , 2days ago.Said that the lab said today is the day to breed. Are there two kinds of progesterone tests at the labs?

I am keeping the bitch until she is no longer receptive, just in case, but kind of blows the whole getting it right, at the right timing theory

I'd bet she ovulated today, breed 2 and 4 days from now.

Sounds like she is considering 1.6 close enough to 2.0, which is the LH surge. As a general rule, ovulation occurs 2 days after the LH surge, so you would estimate progesterone should hit 5.0 in 2 more days. What I have heard is that you should breed 3-5 days after hitting 5.0. If so, she is early.

Bitches can stall at a pre-ovulatory stage, especially if they are stressed by being in a non-home environment. I would not assume that she will progress nicely from a 1.6 two days ago, to a 2.5 yesterday, to a 5.0 today. We all know what happens when we assume, right?
If that were my bitch, I would have done another progesterone today or tomorrow. Recommending to the bitch owner to do another progesterone tomorrow is not out of the question. Problem is, if you test tomorrow you are unlikely to get results until Monday.
I agree with others that breeding today would be too early, because even if she ovulated today, you would still need two more days for the eggs to be fertilized. If you don't have any other options, I would say let your boy, if he is experienced, evaluate her estrus cycle Sunday morning, see what HE says!
Just because your client is a veterinarian doesn't mean she is well-versed in reproductive medicine. She may be relying on you as the stud dog owner to plan the optimum time, and be up against the weekend for testing just like the rest of us.
Ah, such is the life of a stud dog owner!

Thanks!
Kind of what I was thinking. She dropped the bitch off last night and wanted to pick her up today. I said I was not comfortable with the #'s and that I wanted to keep her. She was fine with that. My boy was very interested and tried enthusiasticly (sp), he is not sooo experienced,( one breeding prior, with this same bitch , produced one puppy) it was 10 pm so I just collected and AI'd with the owner. Better to cover her then not.. I will do every other day until not receptive, just because.

So there is only one measurement for progesterone, ng , correct?

Progesterone numbers in Canada are reported in nmol/l (nanamols/liter) In the US, it's ng/ml (nanograms per milliliter)

For an onsite breeding with a bitch who had a small litter last time, beginning on the day of ovulation or the day after isn't a bad plan of action, IMO.

I had a line of bitches that had to be bred very early. We assumed that they ovulated earlier than normally expected and/or their "window" was shorter than expected. If we waited until 2 days after when they were supposed to be ovulating, it would not take. Therefore to get them bred, I would breed at the LH surge and then again at ovulation. Worked every time once we figured it out. Some bitches just don't read the textbook.

Given that experience and how long sperm lives, I tend to breed at ovulation or the day after and then two days later. I am not sure that we have ever missed using this system.