
This is the normal post partum moult. In my girls it normally starts when pups are about 8 to 10 weeks old and goes on for several weeks until they look dreadful with sparse hair that is like wire wool.
It takes until pups are at least four months for them to be presentable and usually when pups are nearly 6 months they may just be showable.
Perfectly normal, but if your breeding from your show bitch in a coated bred you will loose about 9 months of showing.