breeding my dogs

Question
A friend told me that it is okay to breed a dad and daughter shih tzu together, is this true.

Answer
You should consider researching "inbreeding" this is only done by very experienced breeders and for good reason.  There is a high risk of passing on health issues as well as preserving them if you do not know your pedigrees very well.  There have been many times when entire litters have had to be destroyed because of the defects with which they were born with.  Please be careful and do your research.  You are better off to do out cross breedings to start out and do at least a one or two generation separation line breeding.