A recent study offers some further insights. The terminology is a bit scientific but the information, once you wade thru it, is cause for caution!
This is the link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5146839
Tango whelped 6 beautiful puppies yesterday…just one hour after her due date! Sire is Harley, a black and white Grand Champion from Ohio. Her pre-labor lasted just 5 hours and once the puppies decided to come out, they did it in record time. All six were born in a span of one hour, 10 minutes. That is a record for Carneys Haven! Stay tuned for further photos and videos.
