The Basics of Canine Genetics


The term inbreeding typically raises negative connotations. However, the truth is that without inbreeding, pedigree dogs simply wouldn’t exist.Many Breeders call this term “Line Breeding”

Although inbreeding is a critical component of dog breeding, it’s still vital to approach any form of canine breeding responsibly in order to minimise health risks. Here’s what you need to know about inbreeding in dogs.

What is inbreeding?

The Kennel Club emphasises that there’s a clear distinction between inbreeding and incestuous mating, and the organisation prohibits the latter.

  • Incestuous matingrefers to the breeding of close relatives, such as a father and daughter;

  • Inbreeding(Or Line Breeding)is still between relatives, but ones that are much further away from each other on the family tree.

Why is inbreeding/line breeding used?

Inbreeding has been used for centuries to establish particular characteristics, skills, and temperaments in dog breeds. It’s not just a human invention, as inbreeding also naturally takes place in the wild as dogs move in packs.

Breeding dogs in this way can pass physical attributes down a bloodline, with these genetic mutations sometimes becoming desirable among pet owners. This is why inbreeding can be used to perpetuate characteristics such as flat noses, short legs, or other features that can define a breed.


The coefficient of inbreeding

Anyone considering dog mating needs to keep in mind the rules surrounding the coefficient of inbreeding, or COI, too.

When two dogs are being considered for mating, the COI is the probability that they will have inherited the same gene from an ancestor that they both share. In dog breeds that have undergone a lot of inbreeding, this can be quite common.

The higher the COI score, the closer the mating is to being considered “incestuous”, and should therefore not go ahead. Mating two dogs from closely related gene pools is more likely to lead to significant health problems.


What are the risks of inbreeding?

Scientific tests can reveal a great deal about inherited DNA, helping to reduce the risk of any health complications.

These complications can include:

  • Higher puppy mortality rates

  • Reduced litter sizes

  • Short lifespans

  • Fertility issues

  • Inherited diseases and disorders

  • Inherited diseases and disorders

Ultimately, it’s the responsibility of the breeder to ensure that any recessive mutations are managed.

When two dogs with a higher COI mate, there is a greater chance that any shared mutations will be passed to their puppies, making conditions such as hip dysplasia and patella luxation (a deformity in the knees) more likely.

Some of the dog breeds known for inbreeding problemsincludePugs, English Bulldogs, and LabradorRetrievers. It’s worth noting that because of this, insurance costs are often higher when you breed dogs that fall into one of these high-risk categories.

Can DNA tests help reduce inbreeding risks?

Inbreeding is all down to DNA, so DNA tests can be extremely useful when it comes to determining the risk of hereditary diseases and conditions. However, there are limitations - if you don’t know what you’re testing for, it might not show up on a test.

The Kennel Club still advises running DNA tests, but they can only really be used to check for known disorders within a breed, which means continued inbreeding is likely to still lead to the discovery of more previously unknown mutations.

If you’re considering inbreeding, it’s important to understand the associated risks and potential medical complications, yet at the same time, you should think about the benefits - picture your favourite breed and what you love about them in terms of both looks and temperament.

By building a full picture of pros and cons, you’ll be able to make an informed decision on whether inbreeding is the right choice.The Kennel Club advise that mating with a COI above the average for that breed should not be considered and have produced a Mate select tool that can be used when planning a litter.
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