While it is possible to mate a male dog with his daughter, it is a process known as inbreeding and can create problems in the offspring. Inbred animals, which are usually inbred to preserve preferred traits, have a higher incidence of recessive genetic anomalies becoming disabling traits.
Some common negative mutations of inbred dogs include hip dysplasia and patella luxation. Inbred dogs also suffer from lower immune systems and poor fertility, and tend to be less intelligent, and, thus, less trainable than non-inbred dogs. Inbred dogs may also be more aggressive and display more behavioral problems than their non-inbred counterparts.