What Does Clear, Carrier, and At Risk Mean in Dog Genetics

These three terms appear on every genetic health report — and understanding them is essential for making responsible breeding decisions.


The Three Statuses Explained

Clear

A Clear dog has zero copies of the genetic variant being tested.

A Clear result does not mean the dog is free of all health issues — only that it does not carry this specific variant.

Carrier

A Carrier dog has one copy of the variant.

This is why carrier status matters so much — carriers look normal, which is exactly what makes them easy to unknowingly spread through a breeding program.

At Risk

An At Risk dog has two copies of the variant.


How These Statuses Interact in Breeding

Pairing Possible Offspring
Clear × Clear 100% Clear
Clear × Carrier 50% Clear, 50% Carrier
Carrier × Carrier 25% Clear, 50% Carrier, 25% At Risk
Clear × At Risk 50% Clear, 50% Carrier
Carrier × At Risk 25% Carrier, 50% At Risk
At Risk × At Risk 100% At Risk

The most important rule: never pair two dogs that are both Carriers for the same condition. Every litter would carry a 25% chance of producing an At Risk puppy.


Common Conditions Where This Matters

Breed Group Condition to Watch
Poodles / Doodles PRA (Progressive Retinal Atrophy), DM, vWD
French Bulldogs CMR1 (Canine Multifocal Retinopathy)
Collies / Aussies MDR1/ABCB1 drug sensitivity
Labradors EIC (Exercise Induced Collapse), CNM
Golden Retrievers PRA1, PRA2, ichthyosis

Practical Breeding Strategy

  1. Test both dogs — you cannot manage what you do not know
  2. Check for overlap — if both dogs carry the same variant, reconsider the pairing
  3. Prioritize high-risk conditions first — not all carriers need to be avoided; severity matters
  4. Inform buyers — if you produce any carriers in your litter, disclose this to puppy buyers

A Note on Dominant Conditions

For dominant conditions (where one copy is enough to cause problems), the rules change:

Merle is a good example — a single copy creates the merle coat and is generally healthy, but two copies (double merle) causes significant health issues.


The Bottom Line

Clear, Carrier, and At Risk are not value judgments — they are information. A carrier dog can be an excellent breeding animal when paired thoughtfully with a clear partner. The goal is not to eliminate carriers from your program overnight, but to make informed decisions that reduce the incidence of At Risk puppies over time.