Why low inbreeding isn't always the priority in purebred dog breeding
A look at why purebred dog breeding doesn't always prioritize low inbreeding coefficients, what pulls against it, and how pedigree data and genetic testing can shift that balance.
Inbreeding & COI
COI measures risk. It isn't a verdict
The coefficient of inbreeding estimates the probability that two copies of a gene in an animal are identical because they trace back to a shared ancestor. A higher number points to more shared ancestry between the sire and dam, and usually more risk, but it stays one factor among several rather than a simple pass or fail test.
The number needs context to mean anything
A COI that would be a red flag in one breed might be perfectly normal in another that started from a smaller founding population. Comparing a pairing's COI to that breed's typical range matters far more than looking at the raw percentage by itself.
What COI percentage is regarded as safe?
There isn't one figure that works across every breed. Many breeders try to stay below their own breed's average, which differs quite a lot from breed to breed.
How is COI worked out?
It's worked out from a pedigree, tracing shared ancestors back across several generations. Most breed registries, together with a number of online tools, can calculate it once a pedigree is submitted.