Pregnant female dogs (bitches) still need to be wormed. They are giving up a lot of bodily energy to their puppies. Having a worm infestation on top of a growing litter can be harmful for the bitch. It's best to give dogs or bitches a deworming pill once a month. Roundworms and tapeworms are the most usual kind of worms a pregnant dog will carry. When the bitch is infested, so will the puppies.
Work with your vet to determine the day of the puppies conception. If you were present at the mating and made note of the day, then skip this step.
The pregnant bitch needs to be wormed at day 40 of her pregnancy or as close to that day as possible.
Administer worming tablet of appropriate dosage for your dog's weight. Many tablets are chewable and flavoured. If the tablet needs to be swallowed, wrap some cheese or peanut butter around the tablet and the hungry pregnant dog will usually gulp it right down. If she can't take tablets, then she either needs the vet to give her an injection or use the liquid form of Nemex or Pro Wormer 2 (pyrantel pamotate).
A liquid dose is 1 teaspoon (or 5ml) for each 4.54 Kilogram of your dog's weight. Put it in a syringe or spoon. Nemex is sweetly flavoured, so some dogs lap it right up off of the spoon. Others need to be held and have the syringe placed behind the teeth and then slowly administered.
Administer another round of worming tablets, liquid or an injection two weeks after the puppies arrive or when your veterinarian advises. If using Panacur (see below), then administer it two days after the puppies are whelped.
Keep treating for external parasites like fleas as long as your veterinarian says it is safe. Parasite bites often transmit internal parasites. For example, fleas can transmit tapeworms. In the UK, Panacur is the name brand of dewormer safe for pregnant bitches used the most. Double-check with your particular deworming medication, but usually you don't need to have your dog fast before getting the medication.
Do not use this article in the place of your veterinarian's advice. Do not expect 100% of all the worms in a pregnant bitch to be killed, but a lot of them will be and that can make all of the difference.