Not really... But her temp. Will drop several degrees before active labor. When she's getting close.. Take her temp daily.. When it drops below 100*, you can pretty much guarantee that she'll start labor with in the next 24hrs.
No. What happens is that the temperature of the dog drops just when she is about to give birth. You can take the temperature rectally. A normal dog temperature is between 100.3F to 101.3F. But eight to twenty four hours prior to giving birth this temperature will drop to 98 F. The pit bull will also decline to eat anything just when she is about to give birth.