A dam approaching full term, day 60, will start to shed her plug. Notice the dried-up mucus plug. This plug can shed, or shed a little daily for up to a week before delivery; four to five days prior is very common.
A mucus plug and a full-term dam’s vulva
Dam's vulva at day 59—The day or two before whelping you will notice the area around the vulva swelling up and becoming two to three times more puffy.
Dam's vulva day 60
Dam's vulva day 60—you can almost see it puff up overnight. This dam is about to go into labor (hoping tomorrow). She has five pups to deliver.
Shaved belly of a full-term dam
This dam is full term, on day 60. She has shed her mucus plug, so I figure she will have her pups one to three days from now.
Courtesy of MistyTrails Havanese