Dominant vs Recessive Genes in Dogs, Explained Simply
Why one copy of the furnishings gene gives a doodle its beard but a long coat takes two copies: dominant and recessive genes in dogs, what a carrier is, the odds for each pairing, and the traits in between.
By PuppyGenes · How we research and write our guides
A dominant variant shows its effect with just one copy, while a recessive variant only shows when a dog has two copies, one from each parent. In dogs, the furnishings variant behind a doodle's beard and eyebrows is dominant. The long-hair variants of the FGF5 gene are recessive, which is how two short-haired parents can have a fluffy, long-haired puppy.
The short version
- Dominant: one copy is enough. Example: furnishings, from the RSPO2 gene.
- Recessive: it takes two copies. Example: a long coat, from the FGF5 gene.
- Carrier: a dog with one copy of a recessive variant. It doesn't show the trait but can pass it on.
- In between: with incomplete dominance, one copy has a partial effect and two copies a stronger one, as with curl and merle.
- Dominant doesn't mean common or better. It only describes how many copies it takes to show.
Dominant: one copy is enough
A study of more than 1,000 dogs from 80 breeds traced furnishings to an insertion in the RSPO2 gene and found that one copy is enough to show. So a puppy's chance of furnishings depends on how many copies each parent carries:
| Parents' furnishings copies | Chance each puppy has furnishings |
|---|---|
| Either parent has two copies | Every puppy |
| Both parents have one copy | About 3 in 4 |
| One parent has one copy, the other none | About 1 in 2 |
| Neither parent has any | None |
Our guide to furnishings covers the research, and our guide to doodle generations shows the odds for each kind of doodle litter.
Recessive: it takes two
A long coat works the other way. The long-hair versions of FGF5 are recessive, so a dog needs two copies to grow a long coat:
| Parents | Chance each puppy has a long coat |
|---|---|
| Two long-coated parents | Every puppy |
| A long-coated parent and a short-coated carrier | About 1 in 2 |
| Two short-coated carriers | About 1 in 4 |
| A parent with no long-hair copies | None |
Our guide to long coats explains why two different long-hair variants together still give a long coat.
Carriers
A carrier has one copy of a recessive variant and one copy of the usual version. It looks just like a dog with no copies, but it passes the variant to about half its puppies, on average. When two carriers are paired, about one puppy in four is expected to inherit two copies and show the trait.
The same logic applies to some inherited health conditions, which is why breeders may test their dogs for carriers. The PuppyGenes report doesn't include genetic disease or health screening, so talk to your vet about that kind of testing.
In between: incomplete dominance
Some variants have a partial effect with one copy and a stronger effect with two:
- Curl: one copy of the KRT71 curl variant usually gives a wavy coat, and two copies a curly one, as our curly coat guide explains.
- Merle: one copy of the merle insertion gives the marbled pattern, and two copies make a "double merle", which research has linked to much higher rates of deafness. Our merle guide has the details.
More than two versions
Some genes have several versions with an order of dominance. The ASIP gene, behind many coat patterns, has four main versions: sable, wolf-like agouti, tan points and recessive black, in that order. A dog shows the pattern of the more dominant of its two versions, as our coat colour hub explains.
Frequently asked questions
- What does dominant mean in dog genetics?
- A dominant variant shows its effect with just one copy. The furnishings variant of RSPO2 is dominant, so a dog with one copy has a beard and eyebrows.
- What does recessive mean in dog genetics?
- A recessive variant only shows its effect when a dog has two copies, one from each parent. The long-hair variants of FGF5 are recessive, so a dog needs two copies to grow a long coat.
- Can two dogs without a trait have a puppy with it?
- Yes, if the trait is recessive and both parents are carriers. On average, about one puppy in four from two carriers inherits two copies and shows the trait.
- Is a dominant trait more common than a recessive one?
- Not necessarily. Dominance describes how many copies it takes to show a trait, not how common a variant is. A recessive variant can be very common: every dog with a long coat from FGF5 carries two copies.
- What is a carrier dog?
- A carrier has one copy of a recessive variant. It doesn't show the trait, but it can pass the variant to its puppies.
From general to personal
See how this applies to your dog specifically.
Our at-home Complete Dog DNA Test adds your dog's own results to these tips across six report sections: breed ancestry, coat colour, physical appearance, temperament and size predictions, genetic diversity and oral microbiome. The report does not include genetic disease or health screening.