Why a Low Genetic Coefficient of Inbreeding (COI) Helps Ensure a Dog is Healthy

When it comes to choosing a new furry companion, one important consideration is the health of the dog. A low genetic coefficient of inbreeding (COI) can play a significant role in ensuring that your dog is healthy. In this article, we will discuss what ​coefficient of inbreeding is, why it is important, and how a low genetic COI can help to ensure that your dog is healthy.

What is Coefficient of Inbreeding?

The coefficient of inbreeding is a measure of the degree of relatedness between the parents of a dog. In other words it is a percentage of the dog’s genetics that are identical because of inbreeding in its ancestors.

Why Is ​Coefficient Of Inbreeding Important?

COI is important because it can help to predict the likelihood of health problems in a dog. Dogs that are highly inbred are more likely to have health problems, such as genetic disorders and predispositions to certain diseases. By choosing a dog with a low ​coefficient of inbreeding, you can reduce the likelihood of health problems and ensure that your dog is healthy.

In general, a genetic eCOI of 10% or less is considered an acceptable coefficient of inbreeding and is accepted as not inbred. By contrast, a pedigree COI of less than 5% is usually considered acceptable. Ideally, all dogs would have a coefficient of 0%, but that is not realistic. For this reason, ethical breeders should be actively working towards lowering the coefficient of inbreeding in their dogs’ offspring! A high eCOI is a sign that the breeder has not been responsible in their breeding practices, which puts the puppies they sell at a significantly higher risk for developing genetic health problems. 

Coefficient Of Inbreeding & Breed

When evaluating ​coefficient of inbreeding, the breed of the dog must also be considered. This is because some dog breeds are more prone to genetic health problems than other breeds, which is often because that breed has a very high coefficient of inbreeding average! With a high ​coefficient of inbreeding, the potential for health problems increases significantly.

As a whole, our breeds – Havanese and Maltese – are far less inbred than many other dog breeds. As reported by the UK Kennel Club, the average Havanese pedigree Coefficient of Inbreeding is 2.7%. Embark Vet reports an average genetic ​coefficient of inbreeding of 12% in the Havanese dogs they have tested. Likewise, as reported by the UK Kennel Club, the average Maltese pedigree ​coefficient of inbreeding is 5.5%. Embark Vet reports an average genetic ​coefficient of inbreeding of 17% in the Maltese dogs they have tested. A lower genetic COI dramatically reduces the risk of genetic health issues in our dogs. For more information on COI, please visit: Genetic Coefficient Of Inbreeding and  A Beginner’s Guide To COI .

How a Low COI Can Help To Ensure a Dog is Healthy

A low COI helps to ensure that a dog is healthy in several ways:

  1. Reduced Risk of Genetic Disorders. Dogs with a low ​coefficient of inbreeding have a reduced risk of genetic disorders, such as hip dysplasia, eye diseases, and heart problems. This is because a low ​coefficient of inbreeding means that the dog is less likely to have the same genes from its ancestors, reducing the likelihood of genetic disorders.  
  2. Increased Diversity. A low ​coefficient of inbreeding also increases the genetic diversity of a dog, which helps to reduce the likelihood of health problems. A diverse gene pool can help to prevent the expression of deleterious recessive genes and reduce the incidence of genetic disorders.
  3. Improved Immunity. A low ​coefficient of inbreeding can also help to improve the immunity of a dog. A diverse gene pool can help to provide a stronger immune system, reducing the likelihood of infections and other health problems.
  4. Better Physical Characteristics. A low ​coefficient of inbreeding can also help to improve the physical characteristics of a dog, such as its size, conformation, and coat. This can help to ensure that your dog is physically healthy and capable of performing its intended function, whether it be as a companion, working dog, or show dog.  
  5. Longer Life Expectancy. Dogs with a low ​coefficient of inbreeding have a longer life expectancy than dogs with a high ​coefficient of inbreeding. This is because a low ​coefficient of inbreeding reduces the likelihood of health problems, allowing your dog to live a longer and healthier life.  

How to Determine ​Coefficient Of Inbreeding

There are two ways to determine the COI of a dog. It can be calculated in one of two ways: genetic testing to determine the exact COI or pedigree calculations to determine an approximate COI.

The most accurate way to determine the ​coefficient of inbreeding of a dog is to have it tested with Embark Vet. This method is the most accurate because it evaluates the dog’s actual genes and gives a percentage based on those genes. Not only does Embark testing provide the coefficient of inbreeding of the dog, but they also provide a Pair Predictor Tool that allows you to calculate the estimated coefficient of inbreeding (eCOI) of two tested dogs’ offspring.

The second way to calculated coefficient of inbreeding in a dog is to calculate it based on the ancestry of the dog using its pedigree. The ​coefficient of inbreeding takes into account the number of generations between the dog and its common ancestors, as well as the number of common ancestors that the dog has. Determining the ​coefficient of inbreeding based on pedigree is not very accurate compared to genetic testing.

It is important to remember that pedigree COIs will often be significantly lower than the actual genetic ​coefficient of inbreeding of the dog. This is because pedigree COIs are dependent on incomplete information whereas genetic COIs are determined using a complete data set.

For example, a breeder we know has a mama dog whose pedigree COI is 0%, which is very impressive and considered not inbred at all. But when the breeder had her dog tested with Embark Vet, her genetic COI was actually 40%, which is very high! The breeder was shocked, because she had assumed her dog was not inbred – based on her pedigree COI - and that her puppies would therefore also not be inbred.


In conclusion, a low ​coefficient of inbreeding is an important factor in ensuring that a dog is healthy. By choosing a dog with a low ​coefficient of inbreeding, you can reduce the likelihood of health problems, increase the diversity of your dog's gene pool, improve its immunity, and ensure that it has better physical characteristics and a longer life expectancy. If you are considering adding a new furry companion to your family, make sure your breeder follows a breeding approach that leads to strong genetics and remember to consider the ​coefficient of inbreeding of the dog and specifically select a dog with a low ​coefficient of inbreeding.

Our Dogs' COIs

Each of our  parent dogs'  coefficient of inbreeding is listed on their individual pages, along with their complete Embark genetic test results.  We are completely transparent with our dogs' genetic testing, so you can examine the results for yourself.  

We also include the expected coefficient of inbreeding (eCOI) of each litter on the  Upcoming Litters pages.  To learn more about eCOIs, please visit  Why You Should Know The eCOI Of A Puppy Before You Buy It  

To inquire about our puppies for sale , please toss us a question here . We'll be sure fetch!

COI: Other Pages

What's Included
Puppy Waiting List
About eCOIs
Baxter & Bella Dog School
Rearing Methods
Why Use A Holistic Vet
Ambient Sounds
Breeding Approach