
rocknrose,
I too have had this problem with my girls. It took three missed matings, two different bitches, before
I thought of the Canine Herpes. Vaccinated my girl at the next attempt, and sure enough,
she had a nice litter without any problems.
You vaccinate twice, approximately 10 days after the season starts, and around two weeks before the due date of whelping.
If you have more than one brood bitch, remember if one has it, it's likely they all do.
HTH
Karen