
it is very important to be sure there is no actual pregnancy if thinking of using anything to dry up the milk.
A bitch in my breed was pronounced not in whelp so went back to her novice owners (it was a breeding terms arrangement).
She had milk so their vet prescribed Galastop, they had told him that she had been mated, but he was sure she wasn't in whelp.
What happened was the bitch went on to whelp, needed a C section, and the Vet doing the C section couldn't understand how the pregnancy could have been missed.
The poor bitch had no milk, and it turns out that she could have lost the litter because of the medication (they did loose one), they hand reared for over a week when the milk finally came in, luckily Mum had been looking after the pups from birth.