If you're at all interested in genealogy, you know what a family tree looks like. It starts with one line, showing your name, and branches out to show your parents, grandparents, and earlier generations. A pedigree is your pug's family tree. It usually goes back at least three generations and sometimes five or more.

Reading the Pedigree

When you look at a pedigree, your pug's name, breed, and date of birth appear in the top left corner, as well as its sex, registration number, color, and the breeder's name. Starting from the left, you'll see the sire's name, with the dam's name below. Moving on to the right are the names of your pup's four grandparents, with paternal grandparents on top and maternal grandparents on the bottom. The next column shows the great-grandparents, and so on. Males are always listed on top, females on the bottom.

Titles and Health

The pedigree also shows what titles a puppy's ancestors have earned. In the case of a pug, these will be mostly conformation titles. You're not going to find a lot of pugs with obedience titles, for instance. Titles are good, but they're not everything.

Ask the breeder about the health status of the dogs in your pup's pedigree. Is Grandma Pug still alive? Has she developed any hereditary health problems as she's aged? How old was Great-Grandpa Pug when he died? The more dogs in a pedigree that are known to be free of problems, the better the chance that your puppy will be healthy, too.

A pedigree is not a legal document, but the breeder should sign it, certifying that it's accurate. A pedigree is nice to have, but it's not really important unless you plan to show or breed your pug. The following sections discuss some terms that are useful to know as the breeder explains your pug's heritage.

Inbreeding

Inbreeding is the mating of dogs that are closely related, such as father to daughter or brother to sister. When we hear the term “inbreeding,” we picture puppies with physical or mental defects, but when done properly, inbreeding is a valid technique that can strengthen a breeder's lines by setting type, or good characteristics. When the dogs used for inbreeding are free of hereditary disease and have excellent conformation and temperament, the result can be a litter of beautiful, healthy puppies.

While inbreeding works well when the dogs involved have superior attributes and few or no defects, it can lead to serious problems if the opposite is true. Inbreeding intensifies good qualities, but it also magnifies flaws. Inbreeding requires in-depth knowledge of the pedigrees of both dogs so that the breeder is prepared for any diseases or defects that could arise from the breeding.

Line Breeding

Line breeding is a form of inbreeding. Like inbreeding, line breeding is the mating of related dogs, but the degree of relationship is not as close. Examples of line breeding would be a bitch to her grandsire or a dog to his granddam. It's another way to enhance good characteristics. Again, dogs that are line bred should be of the highest quality in health, conformation, and temperament.

Outcrossing

An outcross is the breeding of two unrelated dogs. It's used when a breeder wants to introduce a desirable attribute into his line or to correct a fault that has shown up in the line. Outcrosses can help maintain good health and vigor in breeding stock. They have the added advantage of helping to preserve genetic diversity in a breed. The disadvantage of an outcross is that it can bring hidden genetic problems into a breeder's line.