I can testify as to the amount of hair that accumulates in a week. Last Tuesday I had shoulder surgery and today was the first day I was really up and about. Hubby did not vacuum as he didn't want to disturb me. There are hairballs everywhere, the edges of each wall, clumps under the furniture, mounds under the radiator, etc. I'm afraid to go upstairs. This is from two regularly groomed GSDs. The experiment ends tomorrow as I'm breaking out the shop vac. I knew that GSDs shed, but never this amount.
Furminator is a wonder brush. Just be prepared to be covered in hair as the loosened undercoat clings to everything.
Freyja GSD- 6/21/10
Bevin (princess kitty) 08/27/07
Porsche: kitty 7/2012
Teddy (collie)- 1990-09/13/2006
Franklin (collie) 1996-06/26/2006