
The dosage is a quarter of the adult dose, so 5ml daily for a 20kg bitch.
The life cycle of the canine roundworm means that Larva in a bitch puppy encyst in her tissues (they do in males of course too) and it is the pregnancy hormones that awaken them, and they transfer to the new hosts (puppies) via the placenta, and through the milk.
Worming at this stage of pregnancy reduces the transference of worms larva into the puppies so when they re born they only have a minimal worm burden about 2% of what they would have had.
These of course develop in the puppies, but won't cause such an issue as a heavy worm burden would have,a dn the pups are then treated to remove these.
The better puppies are wormed, especially bitches the lower the amount of worm larva there will be to encyst in the bitch to pass onto the next generation.