Can a brother and sister Yorkie (dog) mate without genetic complications? How about a father and daughter, or mother & son?
Simple answer: absolutely not. It is not safe at all to breed two individuals in the same family, especially as close as those you are specifically asking about. The reason pure breed animals have so many problems is just because of these sorts of breeding practices. Basically, the same genetic problems that people have breeding with family members hold true with these animals (hence the reason it is not legal for family members to marry, at least in the US). If there are any recessive genes that are going to cause problems for the offspring, they will most certainly be expressed through inbreeding.
University of Wisconsin
Click here to return to the Veterinary Topics Archive
Update: June 2012