Quote Originally Posted by Muddy4paws
What age should a pup leave its mum?
8 weeks is normal, 10-12 weeks is best.

is it different for bigger dogs or not?
Nope

I know there are some disadvantages of leaving the mum early but I'm not 100% on them.. I know about the socializing and the pups needing to feed from their mums but thats all, so does anyone know more?
They learn a lot from their littermates and mom in that time.

I also want to know how old a pup needs to be before it starts eating solids?
They start weaning from their mom at 3-4 weeks. They are usually on solid foods at 6 weeks.

What age can a dog start knowing comands? I mean like sit and stay properly? or is it all different?
You should start traning as early as possible.