Autumn Golden Retrievers​​

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Our litters are 0% COI for up to two years longer life expectancy. 

After you read this page, you should be able to:

 1.  Know some of the health problems caused by inbreeding dogs,
 2.  Understand what inbreeding is (mother compared to father),
 3.  Understand how Coefficient of Inbreeding (COI) is a measure of inbreeding,
 4.  Understand that a major study shows high COI reduces life span by 2 years,
 5.  Look online in to find the COI for a litter that you are considering.

 Health Problems Caused By Inbreeding Dogs

            Inbreeding increases reproductive problems, increases puppy mortality, causes a general weakness and immune deficiency, and can bring out any bad recessive traits that would otherwise remain hidden and not be an actual problem.  Cancer is a complicated subject, but a strong immune system is important to fight cancer and inbreeding weakens the immune system.

            I learned firsthand the dangers of inbreeding dogs about forty years ago while still in high school.  I was a junior member at the Salem County Beagle Club.  I did a lot of work for the club and a wealthy member gave me a female puppy from his top bloodline which was linebred (inbred) on a successful field trial stud dog.  This pup would have cost someone else a month's salary so I was very grateful.  When she was old enough to breed, I was also given a field champion stud service.  The pups that resulted were almost too weak to nurse.  I learned the hard way that it is normal to lose puppies during the first days of an inbred litter and that nothing could be done.  Inbreeding just causes weakness.  At the same time, I raised a hunting beagle litter with no inbreeding and puppies that were strong like Olympic athletes.  The hunting beagles did not lose any of their pups.

These links discuss problems caused by inbreeding dogs:

Inbreeding Description

            Most people that had biology in high school, understand that animals have pairs of genes.  They also understand that one gene comes from each parent.  Dogs will have some genes where every dog has the same two genes and we are not concerned about these.  Inbreeding is when there are options for genes, but common ancestors of both parents cause the genes given by the mother and father to be identical copies of the same gene in a common ancestor. 

             When we use a pedigree to discuss the amount of inbreeding, we are looking at the probability that any gene location contains duplicate copies of a gene from a common ancestor.  We are not looking at a specific gene location.

            There are two things happening at the genetic level when  inbreeding  causes gene pairs to be identical copies.  Most diseases or genetic problems are recessive and never become visible in the population because it takes two of these bad genes to show the problem.  Inbreeding is the fastest way to put a bad recessive gene in both the mother and father so it can be doubled up in the puppy. 

            The second problem from inbreeding is that the benefits of being heterozygous (having unlike genes in pairs) occurs in fewer gene pairs.  At first, this must not sound like such a big problem.  If you have experience growing tomatoes or corn from seed in a garden, you may have noticed that the most expensive seeds were labeled "hybrid" and these seeds were worth the extra expense because they grew stronger plants and produced more crop.  These hybrid seeds came from parent plants that were unrelated and intentionally inbred for maximum homozygous gene pairs.  The seeds that you planted were as heterozygous as possible so they were stronger than either parent or other non-hybrid pure strains.  This strength in plants also occurs in animals.  Some immune problems from inbreeding dogs may be due to a low amount of heterozygous gene pairs instead of problems with specific genes. 

            You also need to understand that inbreeding is a result of common ancestors when comparing the mother and father.  Inbreeding can be repaired or corrected in one generation.  Each parent can only pass one gene of a gene pair.  If an inbred dog is mated to another that is completely unrelated, the puppies will not be getting any duplicate genes from an ancestor common to both parents.  In this case, the inbreeding calculation would yield a 0% COI.

Coefficient of Inbreeding

              The COI calculation determines the chance that a puppy is going to have a pair of genes that are identical because they were passed down from the same ancestor on both the mother's and father's pedigrees.  If a stud is a great grandfather on the father's side and a great great grandfather on the mother's side, there is a calculation that tells the COI.  The calculation is straightforward math that requires a computer program.  The database does this calculation for breeders and provides a COI.  A COI of 0% means there is zero chance of a puppy getting a gene from the same ancestor on both parents' pedigrees.  A COI of 25% means that there is a 25% chance that a puppy will have an identical pair of genes from one ancestor at any gene location being considered.  This is what you would get from a father/daughter or mother/son mating.  Some dogs will have a COI this high from the added affect of many ancestors common to both father and mother.

            The number of generations used in the calculation will affect the results.  The farther back you look, the more common ancestors will be found.  Ten generations seems to be the normal amount to use so the numbers are comparing apples with apples.  Some dogs do not have as many generations entered in k9data, so they will have a COI for less generatiions.

The following links include discussion about COI:

High COI Reduces Life Span

             A study of the Golden Retriever data in found almost a two year reduction in life span for dogs with a high COI.  This is displayed on the below chart which was copied from that study's report at:



          The blue dots are thousands of individual dogs.  Some of these individuals lived longer than 15 years and others lived less than 5 years.   

           The red line shows the average life span being about 12 years for low COI and about 10 years for high COI.  This 2 years difference is based on many thousands of golden retrievers.   

​           You can use this red line  to provide you the life expectancy of a puppy that you are looking at.  You need to find the COI for the puppy on the bottom axis of the chart.  Next, you look straight above that to find the red line for that COI.  From that point on the red line, you look straight to the left to see the Lifespan in years.  At the left end of the red line for ZERO COI, lifespan is about 12 years and on the right end of the red line, lifespan is about 10 years.

Using To Know COI

            Avoiding inbreeding should be a priority for all Golden Retriever breeders, but unfortunately some of the puppies sold to family homes have a high level of inbreeding.  There is an online database that can be used by breeders to calculate the level of inbreeding for any mating that they are considering. calculates the level of inbreeding using math accepted by genetic experts.  The COI or Coefficient of Inbreeding is provided for every dog in the database and every proposed test litter.  Most dogs used for breeding already have their pedigrees entered into by either their owner or the owner of one of their puppies.  Breeders can create a "test" mating in the database and learn the COI for puppies that would be produced by that test mating.  This calculation is well understood and approved by genetic experts, but it has not been used by many dog breeders in the past. 

            If you want to know the COI for an adult dog, start at the k9data Home page.  Enter the dogs AKC name in the Search box to open the page for that dog.  On the lower left side of that page, click on the link called "Show genetic information".

            If you want to know the COI for a litter, you have two possibilities.  If the breeder has already created a "test breeding" in k9data, then the breeder can email you a link to that test breeding.  This is a very easy way for a breeder to give you both the pedigree and COI information, so it is reasonable for a buyer to request this link  Once you are on the page for that litter, you select the link for "View genetic informaiton". 

An example litter has the below pedigree.  Open the pedigree link and then select "View genetic information" to see the puppies COI:

            You do not need to be the breeder to create a test breeding.  If you know the AKC names of the mother and father, you can select "View, edit or add test breedings" on the home page.  You may have to register before you can use this feature.  Also, this service relies on donations.  The COI data is updated about once a month, so you will need to plan ahead or time it right.

            You will have a difficult time finding a puppy from parents with show champion bloodlines and that has a COI under 10% because there are only so many champions.  Most show dogs have pedigrees full of show champions.  Breeding to champions is the fastest way to make puppies with the desired look.  If you look at some of the champions in, their "genetic information" will usually show a COI of at least 10% and sometimes more than 20%.  ..

             Inbreeding is acceptable to some of the breeders involved in competitions because that is the best way to produce puppies that will have the traits needed to win.  Everyone says they are against inbreeding, but then some will produce litters with high COI numbers in the 20% to 30% range.  COI is not so well understood by breeders who learned genetics before made the calculation available.  In the past, talks of genetics were short on facts with some breeders claiming that their "line breeding" was not inbreeding, while no one could define the difference between the terms. 

            Now that COI calculations are available to breeders, it is time for buyers to start avoiding inbred puppies.  This is much like the other health certifications.  If buyers will start asking for puppies with a COI under 10%, then the breeders will follow.  Until buyers make this a priority, the current tolerance of inbreeding is likely to continue.