10-24-2012 02:01 AM
Thank you for your question.
There are a variety of clinical signs that you will see you when a dog is about to enter the delivery process. In general, nesting behavior (finding an isolated comfortable soft warm place for the puppies to be born is seen). Additionally, there can be decreased appetite and water consumption. Have a more clinical perspective, body temperature will reduce to below the normal range (102-102.5).
Here is a petMD article that thoroughly covers the topic: