deciding when puppies should be weaned depends largely on the number of puppies a female produces. If she has 8 strong nipples and plenty of milk for 6 puppies than weaning should be started later than the norm.. However if you see that your bitch has for i.e. 8 nipples and has 8 to more puppies than weaning should start at 3-3.5 weeks of age when the pups are on their feet and can lap and drink. They should be having gruel which consists of pulverized dog kibble and some goat milk for starters and the consistency should be very soupy. As they graduate and start getting their little LOL shark teetch they should be getting mashed food. I usually soak my kibble with a ton of water a day before and put in fridge. In the am. the kibble is totally soft and I heat it in the microwave ad a bit of goat milk and mash the food giving it to the pups. As they develop their deciduous teeth (primary teeth) and can break up the kibble and chew and swallow then you put a bit of water and let them exercise their teeth and jaws so that built some muscle and strength to the foreface. Before you start weaning your puppies you will have to deworm both them and the mom.
I use Strongid-T three times 10 days apart to deworm my puppies even if I do not see any evidence of parasites, I still do not take a chance.
My formula for deworming puppies is as follows:
I weigh each puppy in ounces. I divide the puppies (ounces) weight by 16 and then multiply it by 0.05 this is the amount in ml/cc that you give to each pup when you deworm them. At the same time you need to also deworm the mom. Then you start to wean. Purchase yoursel from your vet or the nearest pharmacy a 1cc/ml syringe (no needle) and this is what you will use in order to aspirate the Strongid-T liquid that will deworm your pups. It is an excellent dewormer and very safe. They use it for horses to, but Alas not in the same quantity measures, LOL
Good luck.