Line Breeding

This is the type of mating most used and accepted amongst the top breeders. This is usually a mating between grandfather and granddaughter, uncle to niece, etc. Dogs that are related but once or twice removed and breeders that have knowledge of the genetic lines of these dogs are more likely to produce puppies of a good quality and type.

In Breeding

In breeding is when a mating takes place between dogs very closely related, i.e. brother to sister, mother to son, or father to daughter. This creates a very small gene pool so highlighting the bad genes as well as the good genes. Deformities can also be attributed to this type of breeding. It is, therefore, only recommended to those who have sufficient experience in the lines of the said dogs. Even then there are no guarantees.

Out Crossing

When a mating between two totally unrelated dogs takes place, thus throwing many different genes into the pool, it makes it more difficult to determine the characteristics and type of the resulting litter. However, introducing an outcross stud dog to a pedigree with a very small gene pool can bring in much needed fresh genes. This type of mating is recommended for the breeder with extensive knowledge.

Summary

From a breeding standpoint it is far better to use a stud dog that may be an average individual, but from top quality stock, than use an above average individual from poor quality stock. It is also true that many times a great show dog produces only average prodigy while his little known brother obscured by the great dog's eminence produces progeny of above average quality.