Is it wrong to mate two, brother and sister dogs?

[Radoom von Dobermann]

Seems weird... But I've seen some pedigree's, in which brother and sisters were mated. Is there any risks involved in that?



--But in humans? P.S. I don't have a sister, nor a brother.
http://www.dobermann-review.com/females/Focus_Once_Upon_a_Time/ped.php
I'm just looking forward to purchase a healthy dobermann puppy, and I noticed some weird pedigree in which bro's and sis's were mated...
*pedigrees