Dog breeding is kinda like life, if you don’t have a map, how can you get to your destination without getting lost along the way? And without a map, you may not end up in Beautifulcity like you wanted, but in Disasterville! Without a map (or plan), success in breeding is just dumb luck. You don’t know how you got there, or how to get there again.

A dog is considered a purebred if it is a member of a recognized breed or has five generations of like-to-like breeding behind it. The breed standard will specify all areas of coat, color and conformation and a purebred will approach this standard in all areas. Breeding should be about predictable results. Take two bitches that look exactly alike, one a purebred and one a mutt, and breed them to a purebred male —you’ll see the value of predictable results. But do not accord an equal status to every dog called "purebred", for genetic purity, like a multi-generation pedigree, means little in and of itself. It is important only in terms of the individual breeding animal or program to which it applies. Just as a mutt can have a pedigree, an ugly, nasty tempered and sickly dog can be a purebred, though I hope nobody would want to perpetuate such an animal.

An animal has both a phenotype, or outward appearance, and a genotype, or genetic make-up. Part of the genotype can be determined from the outward appearance. For example, if a dominant gene is present, such as the gene for plush coat or strong ears, it will be visible. Part of the genotype can be hidden. A smooth coat, strong eared Shiloh can carry genes for plush coat and soft ears, both recessives. A smooth coat Shiloh with soft ears — both recessives — must be homozygous for these two traits: one gene for coat and one for ears was received from each parent, and in this case, both genes are the same. A plush coat, strong eared Shiloh can also be homozygous for plush and strong ears if it received identical genes from both parents for these features. However, it may also be heterozygous if it carries smooth coat and soft ears as a hidden recessive, and these can be passed to its offspring. An animal is homozygous or heterozygous only in respect to a gene pair; the whole animal is homozygous for some features and heterozygous for others. An animal that is homozygous for a large percentage of genes will be prepotent since the variation in genes it passes to the next generation will be smaller than in the largely heterozygous animal. When dogs are bred together they can be inbred or outcrossed. Inbreeding is the mating of near relatives; outcrossing is the mating of unrelated individuals.

A breed is created when its characteristics are fixed by breeding to other animals with the same characteristics. In most breeds this has been done by breeding together closely-related animals. The continual breeding together of inter-related animals results in the fixing of the breed characteristics by raising the level of homozygosity in the breed population. Every purebred animal is prepotent to a certain degree: and herein lies the value of breeds. A high degree of homozygosity can result in a breed that is extremely prepotent, that is, likely to pass on its characteristics to its progeny, even when bred to an unrelated animal. Individuals, breeds and strains within breeds can be more or less prepotent than others. As a breeder, you should attempt to determine the prepotency of your breeding animals through litter evaluations and in your study of other strains and animals in your breed. Most breeds have a few individuals that stand out as especially prepotent (Kari!). Keep in mind that an animal can be prepotent for poor characteristics as well as good. Prepotency is valuable only in terms of the individual. A purebred dog of impeccable ancestry is no more valuable to a breeding program than the mutt next door. unless it is able to pass on its high merit to succeeding generations.

Most human societies have been prejudiced against inbreeding, and this prejudice is often carried into animal breeding. The term linebreeding was coined to bypass this bias, though the distinction between the two is nebulous. Inbreeding will increase prepotency, result in puppies that have a similar look, i.e., a true strain, and can be used to fix the characteristics of an outstanding individual for future generations. With each generation of inbreeding the strain is further purified as the recessives are weeded out. If an inbred animal is outcrossed, it's unwanted recessive will remain hidden behind the dominant genes of the unrelated animal: the recessive must be passed on by both parents before it can be made visible. This can happen when an outcross puppy is then inbred.

Each generation of inbreeding will fix the characteristics of the foundation animals, until eventually a high degree of uniformity will be produced in all puppies. Puppies that are the result of an outcross breeding will vary much more: within each litter there may be one superb puppy, a few mediocre puppies and a couple of "dreadfuls"

Inbred individuals are not always superior show animals, but they’re generally preferred for breeding because they will produce offspring that fall within a narrow range of fixed characteristics, and because some of those characteristics are known in advance and can therefore be compensated for. Since perfect individuals are seldom produced it makes sense to choose breeding stock for its faults rather than its virtues. If therefore, the line is known for huge size but tends to have bitchy narrow heads, the preferred choice is the puppy with average size but an excellent head to the puppy with huge size and a narrow head, since this one breaks away from the general trend and is therefore more valuable. The first dog has a better chance of producing offspring with both huge size and good heads than does the second. Such selection will have to be balanced by the priority given to each feature.

Many breeders believe that outcrossing gives a better chance of producing an outstanding individual than does inbreeding. This has been borne out many times in practice. Outcrossing produces a much greater range of quality in the individuals produced. The characteristics of the parents, or of the parent’s bloodlines, do not match. Outcrossing within a breed will produce the occasional individual that is far superior to either parent or to any of its ancestors due to a fortunate combination of genes and many mediocre animals. But the superior individual is not necessarily a superior-breeding animal. The outcrossed dog’s genotype is largely unknown, and he may be entirely lacking in the ability to transmit his excellent features to his offspring. Outcrossing is experimentation, similar to the beginning of breed development. You keep the best puppy from an outcross breeding and then inbreed that puppy to fix desired characteristics. This is done over and over again for generations until you achieve inbred. prepotent puppies with desired characteristics.