Hello,
Pardon me if this has been brought up before. I did check the archives and could not find a similar thread.
One of my girls came into season two weeks ago. Another one also followed suit one month early. The one that came in early had pups in December so I figured she would probably skip a month. Well she didn't and came in four days after the other. It has been exactly one week and now it seems she has come out of season. Now there is no swelling and no blood.
Is it possible that she is having a "split heat". I want to breed her so I was hoping to do a progesterone test, but wondered if I was just wasting my time. Any thoughts or comments?

This is only my experience - I have had 2 bitches come in early that I planned on breeding and on each one, they only had 2 puppies. I think they came in early because of the other girls around them. One cycle was very long and took forever to ovulate (23 days) and the other went as normal with the progesterone, but still only 2 pups. My theory is that if the cycle isn't about normal, then they don't produce as many eggs.