When can puppies sleep in the whelping box without there mum?
the mum should start to leave them alone when she feels that they are ready to be left if she decides not to sleep in the box with them then allow her that choice but never forcefully remove her and make sure that she can have access to them at all times even if she chooses not to be with them because she will feel like she needs a little rest-bite. the mother dog instinctual knows when her pups need feeding and there is no defining time when a mother leaves her pups at night it will be when she feels they are able to last the night without her milk.
