Should I breed Inbred Dogs?

Should I produce inbred dogs?

My recent Golden Retriever conundrum: “How do I breed my European line of Golden Retrievers now that I know they are all inbred?”

My research has shown that most (all) European genetics Golden Retrievers (“English Cream”) are 30% (or more) inbred. The average Golden is 21% inbred. There are American lines of 10% (or less) inbred.

As reference, the child of 2 full siblings from 4 unrelated grandparents = 25% inbred / 25% COI

COI = coefficient of inbreeding.

DNA vs Pedigree

DNA is now able to show us the actual COI of a dog. Historically we relied on pedigree research. We look 10-12 generations back and calculate what the COI prediction is for that dog. Often, we run this COI for a potential litter and get 3%-10% COI for many Golden Retrievers. From an ethical breeder mindset, those are nice low inbreeding numbers. We know all pure breeds are of course line-bred. That is why the dogs look and act like their respective breed. But we don’t want those 25% COI full sibling numbers! So for all of history, we have looked at pedigrees to decide what is safe.

DNA proves our pedigrees are wrong!

DNA is showing a hundred years of line-breeding. And it also shows the truth of hidden inbreeding or outcrossing, meaning a pedigree can be false but the DNA tells the truth.

DNA testing companies to know your Golden Retriever’s COI are:

UC Davis



Back to my question. “Now that I’m informed with recent science, how can I continue to pair my European Goldens together and be an ethical breeder?”

I cannot do it ethically

I know that continued inbreeding brings out the best & worst traits. I know that one single time of doing a tight line breeding can produce the best or worst traits. I know how to set “type” by line breeding. I’ve been mentored on the “old ways” of breeding, and have seen it all since my first litter in 1985.

What I’ve learned in recent years about my Euro line Goldens.

A few years ago I chose an “unrelated” stud (on paper) Luke, to breed to my Brady line. For ease of understanding, Brady is half Australian (Euro background) and Luke is imported direct from Europe. DNA shows Luke 33% COI, Brady 29% COI. On paper in 12 generations: Luke 12.31%, Brady 11.29%. The DNA is correct, it is detecting inbreeding beyond 12 generations.

My Brady’s line is mostly great with an occasional issue. Overall I’m happy. Luke looked like a nice outcross on paper. I bred him to Brady daughters (my best girls) and to my Goldens from other lines, both Euro and outcrossing.

Adding Luke to Brady’s line, “mostly” we had improvement the way I wanted. We improved fronts, stronger squared heads, happy outgoing personality, more boxy body and continued good health. We also kept many great Brady traits I love. Sounds like a win, right?

The problems we got out of this VERY outgoing stud dog, Luke, were extremely shy, skittish and tiny refined Goldens. These dogs are NOT what a Golden should be.

Looking back further, we had occasional small dogs with Brady kids, but not the weird temperament. Back then, before I knew the DNA truth, I thought “it is just an occasional Brady thing, don’t worry, most are not like this”. Unfortunately, with Luke, it became common to see extreme shy, skittish plus tiny pups with the Brady grandkids.

Brady’s daughter Juliet, paired with Luke

Proof of Inbreeding

These next pictures show Embark’s Pair Predictor. Crane Hollow’s Juliet (first picture) is a Brady x Xandra Daughter. The other ladies have zero relationship to Brady x Xandra, and each has a unique pedigree that is not related to Luke. These ladies are all European genetics. It shows each European genetics Golden Retriever has a high COI, plus their puppies would be a high COI when paired to a European stud, Luke.

What about outcrosses with the European Goldens?

Now, on the other side of the coin, Brady, Luke and their full European children were also very outcrossed for litters. These European genetics Goldens were bred to dogs who were themselves between 5%-30% inbred, but there were NO European line Goldens in these pedigrees.

These outcross pups were never tiny and never weird. We got consistent normal, happy and great pups! These pups were all very consistent to what a Golden should look and act like, plus no weird or tiny dogs. The COI dropped on these litters as well to very nice low COI for the puppies of 5%-15%.


Every breeding of all European genetic Golden Retrirver litters I did were highly inbred.

Brady 29% COI

x Xandra 38% COI

= Puppies 33% COI

Juliet is a Brady + Xandra daughter

I got some outstanding ladies from that Brady x Xandra cross, but looking back I got some horrid things too. Alph dropped dead one day at 4 years old, don’t know why. Buttercup returned to me as an adult with an extreme yeast skin issue and black greasy skin- I fixed it with a raw diet & anti fungal. The bottom line is: these dogs are highly inbred, it was a blessing we did not get more problems.

What is my conclusion?

European Goldens are highly inbred and need outcross infusions.

I’ve looked at DNA COI of Goldens from a lot of pedigrees, not just mine. The lowest all European line Golden I’ve seen is 24% and most are 29-33%. The only time the numbers drop, is in an outcross. Example, 33% Euro Golden, Luke bred to a 19% American Golden, River = 14% COI offspring.

Example of a Luke 33% European Golden paired to RiverSong 19% American Golden = 14% COI for the puppies. This is fantastic!

What about full-sibling breedings?

My hunting Goldens and other lines of American hunting, they are ranging 5%-20% COI. On Embarks Pair Predictor I ran their simulator with full siblings together to see what happens.

Full sibling hunting Goldens that are 17% and 21% each, their offspring are 38%, that adds up!

But the European Goldens are all already up there in the danger zone 30’s. That is sad!

What should breeders do to lower COI?

Knowing better means doing better. I’ve learned how to avoid inbreeding due to DNA testing.

If you are a breeder and just learned about DNA COI, you can utilize Embarks Matchmaker Tool to find low COI pairings.

First, order the Breeders version of Embark DNA test kit (not the pet version).

Once your DNA results are back, there is a list of intact opposite sex dogs for your breed (popular breeds only). You can utilize their tool and find dogs based on titles, distance, COI etc.

Example of matching Juliet with studs in Embark’s database for Golden Retrievers. My search criteria was first dogs listed as “champion/ CH” then I chose highest and lowest COI from these studs. The Euro dogs on the right are not related to Juliet on paper, yet they all yield 30+% COI for potential puppies.


Juliet 8% COI in 12 gen pedigree, 33% DNA COI

Daughter of Xandra & Brady, European Show Golden genetics

Juliet’s K9 Data Pedigree

Juliet’s Embark DNA


River 5% COI in 12 generation pedigree, 19% DNA COI

Daughter of Rory & Piper

American Hunting Golden

River’s K9 Data pedigree

River’s DNA Embark