Lactation during a bitches pregnancy

Question
Hi

I have a four year old great dane, she had one litter nearly two years ago she did very well whelped seven and kept seven.  I also have a 5 year old boy, they both stayed with my parents recently whilst I was away working for a few weeks and it would seem whilst I was away my girl came into season and is now pregnant, which is fine, I have the time and space to whelp a litter.  Unfortunately unlike last time I do not have a note of the dates they tied so I'm now playing a bit of a guessing game on when she will whelp.  I noticed the swelling over a week ago, her nipples are enlarged, but she is not yet lactating.  When can I expect her to start lactating and as a rule of thumb how long prior to whelping would she lactate?  Many thanks in advance for your help.

Answer
Hi Emma. Some girls will get milk in about a week before whelping, some a few days before, and some wait until they whelp before they get milk in. Think back to her first litter, when did she get milk in the last time? Watch for her mucus plug, after they lose that, labor should start within 24-48 hours. How long ago was it that they were at your parents?