I have a pure Rottweiler, short coat and a Rottweiler/Newfiland, medium to long coat.  This tool is WONDERFUL!!  It gets the under coat our and the top coat is not harmed.  Their coat feels so good when you are done grooming them.  I groom every week and they just love it - they see me get the Furminator out and they race to the door.

We also have two very large cats, short coat.  They think it is great also and know when I get it out  - it is a good time coming. 

Really cuts down on the fur on the floor/furniture!!

The fur really comes out so be prepared with a large sack or bucket to put...