breeding my dogs

Question
I have a male yorkie and one of his female pups now lives with us.  Are they allowed to breed and will they make good pups.

Answer
Denise,

Inbreeding is not a good idea unless you are versed in the practice.  Inbreeding is done by professional breeders to improve the line.  Usually two related dogs are bred so that the quality traits can be continued or made stronger.  However, it can be a double edged sword.  While the quality traits are made stronger so can the defective traits.  Unless you are fluent in the past genetic make up of the ancestors you could be breeding defective genes into the line.  These defective genes can go undetected for many generations and that is why you would need an extensive knowledge of the genetic background of both dogs.

Genetic defects can range from something minimal to something extreme.  An example of this would be health disorders.  Say there was a seizure disorder somewhere back in the line, if they both had this genetic disorder then the resulting puppies would have the genes only they would be doubled.  This may not show up in the puppies but skip to the next generation.  

Breeding close relatives is a dangerous thing to do if you don't have the knowledge required to do it.  If you would like a more in depth description of the differences between linebreeding, inbreeding and outcrossing you can visit the AKC website and you will find it there.

On a personal note, I found over the years that inbreeding also produces mean, aggressive puppies.  The more you inbreed the worse the aggression.  Therefore, you end up with puppies that are not loveable.