
I carry on as normal right up until they give birth, of course being sensible about not taking her out in heat, and very strenuous climbs.
I sent a picture of my most recent pregnant bitch a day or two before whelping to friends and they thought she looked like she would only have a couple.
She didn't have a large litter, was carrying 5 of larger than avertage pups, they were 14oz to a pound (rather than the usual 10 to 12oz), one was stillborn. This is her third (and last litter) and she will be 7 on 1st October, so you would ex-ect her to be a bit saggy, not a bit of it.
Pups are now 45 weeks old, content as anything, barely interested in solids, as Mum is doing them so well, and bitch is in excellent conditon, maybe a bit overweight, but this will stand her in good stead for the major moult that comes after puppies in a thick coated breed.
I wouldn't encourage games such as fetch, or any silliness, but would expect her to knwo what she can do.