Page 26 - Chow Life - Winter 2025
P. 26
Pedigrees, AVK, & COI
Understanding Genetic
Diversity in Dogs
You may have noticed that our Chow Pedigree concentrating harmful traits. However, it doesn’t
Database includes AVK and COI percentages. But reveal whether those ancestors carried problematic
what do each of these mean, and why do they matter genes — only that they were unique.
for breeders and the future of our dogs?
WHAT IS COI
Dog pedigrees are more than family trees — they
are strategic tools breeders use to manage genetic COI measures the probability that two identical
diversity, reduce health risks, and preserve desirable genes were inherited from the same ancestor.
traits across generations. Two key metrics often Interpretation:
discussed are the Ancestor Loss Coefficient (AVK)
and the Coefficient of Inbreeding (COI). While • 0% COI = No inbreeding.
both measure aspects of genetic diversity, they are • 6.25% COI = Equivalent to distant cousin
frequently misunderstood. This article explores their mating.
differences, provides examples, clears up common • 25% COI = Equivalent to sibling or parent-
misconceptions, and offers practical guidance for offspring mating.
breeders committed to responsible practices.
Examples: Half-sibling mating - COI = 12.5%. Full
WHAT IS AVK? sibling mating - COI = 25%
AVK measures the percentage of unique ancestors in WHY IT MATTERS
a pedigree.
COI is a direct measure of inbreeding. A higher COI
increases the chance that recessive genetic disorders
UNIQUE ANCESTORS
AVK = X 100 will appear, while a lower COI suggests healthier
EXPECTED ANCESTORS diversity. Still, COI alone doesn’t guarantee safety —
Interpretation: even a low COI pedigree can carry hidden risks.
• 100% AVK = All ancestors are unique, maximum HISTORICAL CONTEXT AND
diversity. BREED-SPECIFIC RELEVANCE
• Lower AVK =Ancestors repeat, reducing
diversity. In breeds like the Chow Chow, which have
experienced population bottlenecks and selective
Example: A 4-generation pedigree should breeding for distinct traits, AVK and COI become
have 30 ancestors. If only 24 are unique: especially important. Historical breeding practices
AVK=24/30×100=80%. This indicates repeated often favored line breeding to preserve type,
ancestors and a reduction in genetic variety. inadvertently increasing COI. Today’s breeders must
WHY IT MATTERS balance legacy with longevity — using AVK and COI
to protect the breed’s future without compromising
AVK highlights how much “fresh blood” exists its identity.
in a pedigree. A higher AVK suggests broader
genetic input, which can help reduce the risk of Rare breeds or those with small gene pools may
naturally have lower AVK and higher COI. In such
- 24 -
