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 is a measurement, not a verdict
The coefficient of inbreeding estimates the probability that two copies of a gene in an animal are identical because they came from a shared ancestor. A higher number means more shared ancestry between the sire and dam, and generally more risk, but it's one factor among several, not a pass or fail test.
The number only means something in context
A COI that would be alarming in one breed might be unremarkable in another with a naturally smaller founding population. Comparing a pairing's COI to that breed's typical range matters more than looking at the raw percentage alone.
What COI percentage is considered safe?
There's no universal cutoff. Many breeders aim to stay below their breed's average, which varies significantly from breed to breed.
How is COI calculated?
From a pedigree, tracing shared ancestors across generations. Most breed registries and several online tools can calculate it from a submitted pedigree.