I remember the first time I received a DNA color panel result for one of my dogs. The report was full of letters and symbols that made perfect sense once I understood them, but initially felt like reading a foreign language. Let me translate that language for you.
DNA testing has revolutionized breeding. What used to require years of test breedings can now be determined with a cheek swab and a two-week wait. But knowing which tests to run, which labs to trust, and how to interpret results requires some guidance.
Why Test in the First Place?
Before we discuss specific tests, let me address the "why." I sometimes meet breeders who feel they know their lines well enough without testing. "I have been breeding this line for thirty years," they say. "I know what colors come out."
Here is what I tell them: You know what colors have come out. You do not know what colors are being carried invisibly, waiting for the right breeding combination.
From my article on hidden genetics, you know that recessive genes can hide for many generations. DNA testing reveals those hidden genes. It transforms guessing into knowing.
Practical benefits of testing:
- Predict litter colors before breeding
- Identify carriers of colors you want to produce or avoid
- Understand "surprise" puppies in past litters
- Make informed decisions about breeding pairs
- Provide accurate genetic information to puppy buyers
The Major Testing Labs
Several reputable laboratories offer canine color testing. Here are the ones I recommend most often:
Embark offers comprehensive panels that include health, traits, and color genetics in one test. Their color results are integrated with the overall report. Cost is higher, but you get everything at once.
UC Davis Veterinary Genetics Laboratory (VGL) is my go-to for pure color testing. They offer individual tests and panels, their research is peer-reviewed, and they maintain excellent scientific standards.
Animal Genetics provides affordable individual tests and panels with quick turnaround. Good option if you know exactly which specific genes you want to test.
Wisdom Panel includes some color genetics in their breed identification tests. Less comprehensive for color specifically but good if you also want breed information.
What I Actually Do
For my own dogs, I typically run Embark for the comprehensive health and trait information, then follow up with VGL for any specific color questions that need confirmation or that Embark does not cover. It sounds expensive, but the information has saved me from costly breeding mistakes multiple times.
Essential Tests for Most Breeds
While specific needs vary by breed, here are the core color genes I recommend testing in almost every breeding program:
E Locus (Extension)
This test reveals whether your dog can produce dark pigment in its coat. Results include:
- E/E - Normal extension, two copies
- E/e - Normal extension, carries recessive red
- e/e - Recessive red/yellow/cream (no dark pigment in coat)
Why it matters: A dog that is E/e looks normally pigmented but can produce recessive red puppies when bred to another carrier. Without testing, you would not know it carries this gene.
B Locus (Brown/Liver/Chocolate)
Determines whether eumelanin is black or brown:
- B/B - Black pigment, not carrying brown
- B/b - Black pigment, carries brown
- b/b - Brown pigment
The B locus is straightforward and among the most commonly tested. If you want to know whether your black dog carries chocolate, this is the test.
D Locus (Dilution)
Tests whether pigment is full strength or diluted:
- D/D - Full pigment intensity
- D/d - Full pigment, carries dilute
- d/d - Diluted pigment (blue from black, isabella from brown)
Health Consideration
In some breeds, the dilute genotype (d/d) is associated with Color Dilution Alopecia, a skin condition that can cause hair loss and skin problems. Before breeding for dilute colors, research whether this is a concern in your specific breed. The D locus test can help you make informed decisions.
A Locus (Agouti)
The A locus controls pattern distribution. Testing reveals which pattern alleles your dog carries:
- Ay - Sable/fawn
- aw - Wild sable/wolf grey
- at - Tan points
- a - Recessive black
This test is particularly valuable in breeds where multiple patterns occur, as described in my guide to the loci.
K Locus (Dominant Black)
Tests whether your dog carries dominant black, brindle, or allows A locus expression:
- KB - Dominant black (overrides A locus)
- kbr - Brindle
- ky - Allows A locus pattern expression
Important for breeds where both solid colors and patterns occur.
Breed-Specific Tests
Beyond the basics, certain breeds have unique color genetics requiring specialized tests:
Merle (M Locus): Essential for Collies, Shelties, Australian Shepherds, and other merle-carrying breeds. Tests for merle and cryptic merle. Crucial for avoiding double merle breedings. For detailed merle breeding guidance, see our partner resource Merle Breeding Safety.
Harlequin (H Locus): Specific to Great Danes. Tests for the harlequin modifier that creates the classic white-with-patches pattern.
S Locus (Spotting): Important for breeds with white markings. Tests for piebald, irish spotting, and related patterns.
Intensity (I Locus): Affects the intensity of red/yellow pigment. Important for breeds like Golden Retrievers where shade varies.
Reading Your Results
When your results arrive, here is how to interpret them:
Notation style: Most labs use either letter pairs (B/b) or descriptive terms (Carrier). Both convey the same information.
Homozygous results: Same allele twice (B/B, b/b, D/D, d/d). Your dog will pass this allele to every puppy.
Heterozygous results: Different alleles (B/b, D/d). Your dog will randomly pass one or the other to each puppy.
Putting it together: A result of B/b D/d E/E means your dog is black (phenotype), carries chocolate (B/b), carries dilute (D/d), and does not carry recessive red (E/E). Understanding how these loci interact helps you interpret what your dog might produce.
Student Question
"My dog tested as B/b. The breeder told me he was from a line that never produces chocolate. Is the test wrong?" The test is almost certainly right. Your dog's ancestors were carriers too. They just never happened to be bred to other carriers, so no chocolate puppies appeared. The gene was there all along, invisible until tested.
Using Results for Breeding Decisions
Once you have results for potential breeding pairs, you can predict litter outcomes. Use Punnett squares or online calculators.
Example scenario: You want to avoid producing dilute puppies because of Color Dilution Alopecia concerns in your breed.
- Your male tests D/d (carries dilute)
- Your female tests D/D (does not carry dilute)
- Prediction: No dilute puppies. Half will be D/D, half will be D/d carriers.
Example scenario: You want to produce chocolate puppies.
- Your male tests B/b (carries chocolate)
- Your female tests b/b (is chocolate)
- Prediction: 50% chocolate puppies, 50% black puppies carrying chocolate.
Common Misconceptions About Testing
"I can tell what my dog carries by looking at its ancestors." Sometimes, but not reliably. Hidden genes do not announce themselves in pedigrees.
"My breed only comes in one color, so why test?" Because someone might introduce genes from outcrossing, or you might discover your breed carries more variation than expected. Testing establishes a baseline.
"DNA tests are too expensive." Consider the cost of an unexpected litter color that affects puppy prices, or the cost of repeat breedings trying to produce a specific color. Testing usually pays for itself.
"If the puppy looks right, the genes must be right." Phenotype does not equal genotype. A black dog could be BB or Bb. Only testing reveals the truth.
When to Retest
In general, you only need to test a dog once. DNA does not change. However, consider retesting if:
- Results seem inconsistent with breeding outcomes
- You used a lab with a questionable reputation
- Sample collection may have been contaminated
- New tests become available for genes not previously tested
If a result seems wrong based on actual breeding outcomes, contact the lab. Errors are rare but do occur. Most reputable labs will retest at no charge if there is a genuine concern.
Building a Testing Protocol
Transparency around genetic results builds trust with puppy buyers and advances the breed as a whole. Amandine Aubert's Bloodreina kennel in France, for instance, shares full color genotype panels for every breeding dog, giving prospective owners a clear picture of what to expect in each litter.
For a serious breeding program, I recommend this testing protocol:
- Test all breeding dogs for all relevant color genes before first breeding
- Keep results on file and share with puppy buyers
- Run predictions before every breeding using actual genotypes
- Test any puppy with unexpected color to understand what happened
- Update your records as you learn more about your lines
This approach eliminates surprises and allows you to make informed decisions about every breeding.
Cost-Effective Testing Strategies
If budget is a concern, prioritize strategically:
- Test your breeding dogs first (they have the most impact)
- Test for genes most relevant to your breed
- Watch for lab sales and package deals
- Consider testing only dogs you plan to breed from
Some labs offer breeder discount programs or volume pricing. It is worth asking.
Beyond Color Testing
While this article focuses on color, the same labs offer health testing that is equally important for responsible breeding. For herding breeds, health tests including MDR1 drug sensitivity should be prioritized. Learn more at The Herding Gene.
Your Action Steps
If you have not started testing:
- Research which color genes are relevant to your breed
- Choose a reputable lab
- Order tests for your current breeding dogs
- Build a database of results
- Use the information for your next breeding decision
The investment you make in testing today will pay dividends in predictability and peace of mind for years to come. No more wondering. No more surprises. Just genetics, understood and applied.
Now that you understand both the basics of color genetics and how to test for them, you are equipped to breed with confidence.