COI checker:
This is an excellent tool from our friends at https://cavalierpuppy.co.uk which helps us understand the meaning of the COI results: https://cavalierpuppy.co.uk/check-health-testing-and-coi/
This page is a work in progress, we are not scientists or geneticists just dog lovers trying to understand what it all means (for our dogs’ futures) and hoping to help you understand too.
This course is an absolute MUST for anyone contemplating breeding a litter: https://www.instituteofcaninebiology.org/basic-population-genetics.html
- Genetic Diversity: refers to the range of different inherited traits within a species or closed population within a species, and is important because it strengthens the ability of species and populations to resist diseases, pests, changes in climate and other stresses
- Coefficient of Inbreeding (COI): a way of calculating how closely related a dog’s parents and their relatives are, which is especially important if they are going to be mated, as it can give a statistical value of how similar on a genetic level any puppies produced could be.
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- Pedigree COI: this looks at the relationship in just a few generations usually between 5 – 10 and ignores relationships further back in pedigrees. To be meaningful it needs to be reconstructed back to the foundation dogs. https://www.thekennelclub.org.uk/health-and-dog-care/health/getting-started-with-health-testing-and-screening/inbreeding-calculators/
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- Genetic (Genomic) COI /DNA COI – this looks at all the generations of a breeds’ development and has a higher standard of accuracy than pedigree COI. https://www.instituteofcaninebiology.org/blog/inbreeding-of-purebred-dogs-determined-from-dna
- Cross-breeding: mating between two different dog breeds to try and produce a “new” breed
- Out-cross: Out crossing originally referred to breeding to a non-relative (with the aim of bringing in new genes) but still within the same breed, but generation after generation it becomes increasingly difficult to do a “true” out-cross as dogs within breeds are very closely related and this is causing “bottle necks” or “lack of genetic diversity” within a breed which is starting to impact health including longevity, fertility and increase in inherited disease. Consequently some breeders with the guidance of geneticists and other experts are redefining an out-cross as a cross-breed to another breed to introduce new genes and then back crossing to the original breed. In this way they increase genetic diversity but maintain the characteristics of the original breed.
- Back-cross: breeding back to the original breed or lineage from an outcross
- In-breeding: the “art” of mating closely related dogs together to fix in their genetic make-up the qualities or conformation the breeder is looking for and “breed standards” require
- Line-breeding: successful inbreeding! This generally means mating related dogs in order to ensure consistency of a physical trait or temperament trait while trying to avoid serious problems that result from more extreme in-breeding.
Why is it even necessary to understand?
Many breeds were built with very limited foundation dogs, the repeated line breeding (inbreeding) performed over the last 100 years over successive generations together with the popularity of certain male dogs has reduced the available genetic material and therefore genetic diversity in a given breed.
So, although dogs of a breed all look very similar and can have similar behavioural characteristics (often referred to as “breeding to type”) there can be detrimental effects on health such as increasing the likelihood of genetic diseases which can reduce quality of life and longevity. Reduced genetic diversity can also affect the immune system with increased susceptibility to infection and immune mediated disease. Conversely increasing genetic variation gives so called hybrid vigour. Reduced genetic diversity also affects reproduction with reduced fertility and litter size.
A recent Norwegian court ruling found that breeding English Bulldogs and Cavalier King Charles Spaniels breached the Nordic country’s existing Animal Welfare Act because these breeds are very predisposed to health problems due to selective breeding. This ban has been supported by the World Small Animal Veterinary Association and the British Small Animal Veterinary Association stating that “breeding should promote traits that provide robust animals with good function and health” and ” Health focused breeding and husbandry practices are the means to improve the health of purposely bred animals. The selection of breeding dogs and cats must avoid the extreme conformation that predisposes to disease and poor welfare” Since, there has been much discussion about dog breeding practices in this country and many organisations are suggesting Outcrossing projects which are properly monitored and run in conjunction with geneticists and other experts.
Further information on COI
https://www.instituteofcaninebiology.org/blog/coi-faqs-understanding-the-coefficient-of-inbreeding
Links to projects:
Genetic Rescue of the Highly inbred Norwegian Lundehund:
Irish Red & White Setter (Irish KC)
Wetterhoun (Dutch KC)
Doberman Preservation Project
https://www.dobermanpreservationproject.com/the-project.html
Bernese Mountain Dog Vitality Project
https://www.bmdvitalityproject.org/
Additional links:
https://www.instituteofcaninebiology.org/blog/lush-on-linebreeding