How to breed healthy sound dogs? Much recent attention has been focussed on theoretical concepts like COI. (Coefficient of inbreeding). Breeders are beset with the problem of reconciling the intuitive truth of the dangers of loss of genetic diversity with the practice of selective linebreeding which has, in many respects, served them well. Of less importance than line breeding vs. outcross breeding is the difference between stupid breeding and intelligent breeding. Outcrossing the wrong two dogs can be much more of a disaster than line breeding the right ones. I have seen this in operation for many years, and would like to offer some of my personal thoughts on good breeding practices.

1. Research. Know what problems potentially exist in any dog you are thinking of breeding. First, get all the information available on the modes of inheritance of all the defects known in your breed. Then comes the hard part. Though outcrossing is a great idea theoretically, in practice it is a field full of landmines. Within your own line, you are pretty sure what is there and what isn't - especially after many years. But when you outcross, do you know what you are getting? Has the breeder of that dog been completely candid? Does he/she even know what problems lurk in his/her dog's genes? What of the unexpected effects of combining two deleterious factors, each rather benign in themselves? Some diseases now appear to be the result mutations at two separate loci. Each of these genes alone seems incapable of producing the disease. Line bred dogs, having only one of these mutant genes are healthy. But outcross them, to a line which harbors the other gene, and disaster strikes! - Whole litters of pups sick and dying in adolescence or early adulthood .
2. The use of pedigrees. I know of breeders who use pedigrees to chose their breedings without regard to the animals. These "breeders" look to "concentrate the blood" of a famous animal, and will send a bitch to a stud without ever seeing or laying hands on him just to concentrate the blood.  This is a disaster waiting to happen - the unholy combination of stupidity and inbreeding!  The pedigree is only useful as a map of the probability that your litter will avoid certain problems and succeed in having some other qualities you want.  Its usefulness is entirely dependant on what you know about each and every animal on it. To me the COI is of very secondary importance to what I know about the five generations of ancestors in front of me. If all these dogs are trash, the smallest COI in the world won't make a healthy and sound pup. And if all the ancestors are sound and healthy, the chances are good that the get will also be, despite a fairly high COI.
3. How to inbreed. You inbreed when you need to "fix" a quality, not just for the hell of it. Suppose I have poor quality coats in my line. Suddenly I come up with a litter which exhibits exceptional coat quality. I don't know where it came from, but I know I want to keep it. I will inbreed on those animals, and I will fix that coat. But how? First of all, I will try to get two rather different looking individuals who have as little as possible phenotypically in common, - except for the coat of course. Why? Because I want to preserve what diversity I can see while inbreeding on the selected quality.
4. How to outcross. First of all, know exactly why you are doing this particular outcross. Let's say I need better angulated rears. I have several lines to choose from, each with the rears I want. All of these lines are remote in ancestry from my dogs. How do I decide (after the normal research on health and inherited defects) which to use. This is very simple: I use assortative phenotypic mating. The dog that looks most like my line will give me the rear plus genetic diversity, but likely will not change my type. This last is important, not only for vanity's sake, but because if I don't like any of these pups, then I won't keep any, and then what's the use of having done the breeding.
5. What to select. This last is the most important. When you have done your outcross, and you have your litter in front of you. What then? All too often, breeders forget why they did the breeding in the first place. They breed for a better head, because their dogs have poor heads. Then they see the litter, and their eye is captured by a pup with a wonderful style and the same old head as usual. They end up selling the good headed pups as pets, and keeping what they already have - perhaps because it is familiar. I always write a contract with myself on the reasons for doing a particular breeding. Then when it comes time to select, I read my contract and make my choice accordingly.