Reading pedigrees and understanding the coefficient of inbreeding

A pedigree is more than a nice piece of paper that comes with a purebred dog. It shows the dog’s ancestry over several generations and so helps to keep an eye on health and genetic diversity. In Flanders, since the Breeding Decree (Fokkerijbesluit), the pedigree is also a quality label. In this dossier you can read what a pedigree is in legal terms, how to read one, what it does and does not guarantee, and how the inbreeding coefficient works.

What is a pedigree?

In Flanders, the Flemish pedigree (Vlaamse stamboom) is the only legally valid pedigree. For dogs born in Flanders, it can only be issued by a recognised breed registry association. That is only possible if the approved breeding programme for the breed has been followed and the parentage has been checked with a DNA test. The document that the Société Royale Saint-Hubert (SRSH/KMSH) issues through the LOSH studbook is a certificate of ancestry: it records the ancestry, but may not be called a pedigree in Flanders.

A pedigree shows, among other things, the dog’s name and microchip number, its date of birth, sex and breed, the breeder, and its parents and earlier ancestors. Titles and health results of the ancestors are sometimes included too.

How do you read a pedigree?

A pedigree reads from left to right. On the left is the dog itself, then its parents: usually the sire at the top and the dam at the bottom. Each column further to the right is a generation older. Next to the sire are his parents, next to the dam hers, and so on.

Look especially for names that appear more than once. If the same dog appears on both the sire’s and the dam’s side, the parents are related. The closer that shared ancestor is to the puppy, and the more often it appears, the higher the inbreeding.

What a pedigree does and doesn’t guarantee

A Flemish pedigree confirms the ancestry, checked with DNA, and shows that the puppy was bred according to the approved breeding programme for the breed, with the mandatory examinations of the parents. A breeding programme reduces the risk of hereditary conditions, but does not offer a 100% health guarantee. A pedigree also says nothing about a puppy’s temperament or socialisation. So also look at the parents’ results, their temperament and the way the breeder works.

Pedigrees in Flanders since 1 July 2025

Since 1 July 2025, the Breeding Decree (Fokkerijbesluit) has applied in Flanders. A puppy born in Flanders may only be sold with a pedigree if that pedigree was issued by a recognised breed registry association. The date of sale on the sales contract is what counts. What else you need to know:

• A breeder is not obliged to provide a pedigree. However, a puppy born in Flanders may not be sold with a pedigree from abroad or from another region.
• A dog born abroad may be sold in Flanders with its foreign pedigree, provided it is clearly stated that it is a foreign pedigree.
• The inbreeding coefficient (COI) of a puppy may be at most 1% higher than the average of both parents, calculated over at least three generations of the parents. There are no exceptions.
• If there is no approved breeding programme for a breed (yet), a lineage certificate (afstammingscertificaat) can be issued. This is not a pedigree: it only serves to preserve the known ancestry data and must look clearly different from a pedigree.
• Which examinations the parents must have is set out for each breed in the breeding programme. Dierenwelzijn Vlaanderen publishes all approved breeding programmes.

Read more in our Pedigree and registration section: the Breeding Decree explained, applying for a pedigree from A to Z and what to look for as a buyer.

The coefficient of inbreeding

The coefficient of inbreeding, often abbreviated to COI, expresses the probability that a puppy has two identical copies of a given gene that come from the same ancestor. The higher that probability, the greater the risk that recessive diseases show up. High inbreeding is also linked to smaller litters, weaker immunity and shorter lives.

Some examples, assuming unrelated grandparents:

• Father x daughter or mother x son: 25%.
• Full brother x full sister: 25%.
• Half-brother x half-sister: 12.5%.
• First cousins: 6.25%.
• Two unrelated dogs: 0% over the generations calculated.

How many generations count?

The result depends heavily on how many generations are included. A COI over five generations is almost always lower than over ten, because older shared ancestors are then left out. So only compare figures calculated over the same number of generations, and always ask how many generations were included when a COI is quoted.

What is a good coefficient of inbreeding?

The Breeding Decree does not set an absolute maximum. It looks at the increase: the COI of the puppies may be at most 1% above the average of both parents. The breed average is also a useful point of comparison, as it varies widely between breeds. A breeder who knows the COI of their matings and can explain how they keep it low is working with care.

Line breeding

In line breeding, more distantly related dogs are mated, for example through a shared grandfather, to fix certain traits. It is a milder form of inbreeding, but not without risk: undesirable traits and disease genes are fixed as well. Repeated line breeding over several generations gradually raises inbreeding. The breeding programmes also prohibit a bitch from being mated by her grandfather, father, brother, half-brother, son or grandson.

The popular sire

Inbreeding doesn’t only arise from mating related parents. When one successful stud dog fathers a great many litters, many dogs in a breed become related within a few generations. Inbreeding then rises across the whole breed, even if individual breeders don’t deliberately mate related dogs. That is why the breeding programmes of Dierenwelzijn Vlaanderen also ask breeders not to use a stud dog too often, so that harmful genetic variants spread less.

Measuring inbreeding with DNA

Some laboratories offer tests that measure a dog’s genetic diversity directly in its DNA. Such a test gives a picture of the actual inbreeding, including inbreeding that goes back to ancestors no longer shown on the pedigree. It is a useful addition to the pedigree calculation, but doesn’t replace health testing.

For buyers: what to ask

• Will the puppy receive a Flemish pedigree from a recognised breed registry association? If the dog was born abroad, is it clearly stated that it is a foreign pedigree?
• Do any names appear twice in the pedigree, and what is the litter’s coefficient of inbreeding?
• Over how many generations was it calculated, and how does it compare with the average of the parents?
• What results do the parents have for the mandatory examinations in the breed’s breeding programme? See also the dossier DNA tests in dogs.

In short

• In Flanders, only the Flemish pedigree from a recognised breed registry association is a pedigree. The KMSH document is a certificate of ancestry.
• A Flemish pedigree confirms the ancestry and that the breeding programme was followed, but does not offer a 100% health guarantee.
• Names that appear on both sides point to a relationship between the parents.
• The COI of the puppies may be at most 1% above the average of the parents.
• Overuse of a single stud dog increases inbreeding across the whole breed.