Inbreeding and Inbreeding Coefficient

Informations based on this article.


A subject is in a situation of consanguinity if, for a given locus, (s)he has two identical alleles, per copy of one and the same ancestor gene. The coefficient of consanguinity (Cc) (or Inbreeding Coefficient (IC)) is the probability that the two allele genes that an individual has at a locus are identical by descendance.

It does not make sense to compare total IC if you do not know the depth of pedigree on which it was calculated.
Cc Comparison makes sense only if made on equal depth of pedigree.. We can compare IC on 3, 4, 5, … generations.

In dog breeding, it seems relevant to consider the IC on 5 or 6 generations.

Important: the consanguinity does not transmit itself. The marriage between two highly consanguineous dogs, without any kinship, will give a 0 % consanguinity puppy.

Direct links about genetics: Inbreeding, Mendel's genetics. These links provide a lot of information on genetics..

Utility of Inbreeding

Inbreeding is useful in breeding to set characteristics within a breed. A breeder can use inbreeding to establish the ears size, the head form, etc.

The counterpart of inbreeding is the raise of homozygosity, and the dropp-off of heterozygosity. Yet this heterozygisity is very important for the survival of a species or a breed.
Example : If a disease affects a species, which inbreeding is such that homozygosity is very important, the entire species can be decimated. However, if this species has a rich genetic heritage with different genotypes or phenotypes, part of the population would survive because the disease will not affect it.

Moreover when a breeder uses inbreeding to set a known characteristic, that he considers like being a quality, he can also favour the emergence of a defect, or a disease, not predictable.

Selection in breeding is complicated and needs to take in consideration all of these parameters.

INBREED © software

This tool is based on an opensource software created by a scientist in INRA, Didier Boichard (Boichard D.,2002. Pedig: a fortran package for pedigree analysis suited to large populations. 7th World Congress on Genetics Applied to Live stock Production, Montpellier, 19-23 août 2002, paper 28-13).

It works is based on a private database created and adapted by us with existing data. It computes the inbreeding coefficient of a dog from 2 to 20 generations depth. It allows to compare inbreeding between several dogs. And, it also computes the inbreeding coefficient of a fictive litter.

Inbreed Inbreed ©

The software we use is based on the VanRaden method.

When you move your mouse over the graph area, a bubble appears with these information :

  • Dog Name or marriage
  • Inbreeding Coefficient
  • Generation number used for computing
  • % of available pedigree in our database for a given generation depth

Using this tool is easy. You just need to enter the dog's name (official name, not nickname). A name list appears with a dozen of names, click on the name you want. If the desired name does not appeared, enter the full official name. If it cannot be found, it may not be in our database.

Your dog may be missing from our database or we may be missing information about its family tree.

If you want it to appear, feel free to contact us and send us the information needed to compute the inbreeding as well as the perpetual improvement of the database (ie. at least: sex, colour (Grey Wolf or brown Forest), date of birth, breed and any other information you are willing to provide us - identification Number, LOF, siblings, genetic testing, possible diseases, etc …).

If the minimum information is missing and you do not want us to share it, there is no need to contact us. We develop this tool in a non-profit organization manner with a spirit of sharing in order to improve knowledge about the breed we love.

These coefficients of consanguinity are based on official pedigrees, publicly available on this website.

Feel free to contact us for any information, issue or remark regarding this tool.