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 works out the odds that two copies of a gene in an animal are identical because they came down from the same ancestor. A higher number means the sire and dam share more ancestry, and usually more risk, but it's only one piece of the puzzle rather than a straight pass or fail check.
The number only stacks up against context
A COI that looks worrying in one breed can be run of the mill in another that started from a smaller founding population. Weighing a pairing's COI against that breed's usual range tells you a lot more than the raw percentage on its own.
What COI percentage is considered safe?
There's no across the board cut off. Plenty of breeders aim to sit below their breed's average, and that average shifts a fair bit from breed to breed.
How do you work out COI?
It comes from a pedigree, tracing shared ancestors back through the generations. Most breed registries and a few online calculators can work it out once a pedigree is submitted.