Answer

I'd check a stool sample to see if the problem is intestinal parasites. The hormonal changes of heat can release encysted parasites to reinfect the bitch (and ultimately her pups) leaving her with an unexpected parasite infection.
You have to be careful which wormers are used if that is the problem so just remind the vet she is pregnant if there are parasites needing treatment.
However some bitches carry pups high and the result is an 'iffy' stomach. I'd not let her eat grass if you can avoid it.
Do several small meals a day for her to make allowances for the lesser space available for food. Be sneaky in feeding her - mix the canned food into the dry and let it sit a little so the dry food softens and tastes like the canned.
Count from the first breeding for expected whelping date. Normal gestation is 58-65 days.
Hope this helps you!

Expert:	NancyH
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Answered:	11/29/2007

Dog Expert:Rescue, Train,Breed,Care

30+ yrs dog home vet care & nursing, rescue, behavior&training, responsible show breeding, genetics