The following information is for the serious breeder.
Some dogs have a problem breeding.
To help determine the exact day a bitch should be bred, the following chart may be referred to. This is information that was developed by Shirley Johnston while she taught at the University of Minnesota. The system requires blood be drawn from the bitch and sent to a lab that can check the progesterone level of the blood. For this to be effective, the breeder needs to find a lab that can give the results on the test back the day after the blood is drawn. This is not a cheap process.