Research reveals declining levels of inbreeding since 2000 

The Kennel Club has analysed extensive data from its pedigree records to launch ground-breaking research that will help breeders to improve genetic health and protect the future of our favourite dog breeds.

The 35-year review, which is the most comprehensive research project of its kind, analyses Kennel Club data from 1980 to 2014 for all 215 recognised pedigree dog breeds and, where numbers allow, calculates the rate of loss of genetic diversity within each. This is quoted as the Estimated Effective Population Size - an important descriptor of the sustainability of a population.

The research shows that, since 2000, the rate of inbreeding has declined or slowed down in the majority of breeds to sustainable levels, meaning that the future is brighter for many breeds - including some of the UK's vulnerable native breeds whose lack of popularity and low numbers are a concern.

All animals in a population will have ancestors in common, meaning a degree of inbreeding and loss of genetic diversity is inevitable. This can be exacerbated by selection for positive and predictable traits (including temperament and health), meaning that the rate of loss of genetic diversity must be kept at sustainable levels to avoid the detrimental effects of inbreeding.

The slowing down of the rate of inbreeding coincides with advances in science that have enabled the Kennel Club to develop its online Mate Select tool, where breeders can look at the genetic risk associated with a potential mating, and also the relaxation of Pet Passport rules enabling foreign, and potentially more distantly related dogs, to be brought into the country more easily.

The Kennel Club will use the research to help breeders develop strategies that will help them continue to prevent the decline of genetic diversity on a breed-by-breed basis.

Dr Tom Lewis, Quantitative Geneticist at the Kennel Club and author of the research, said: "Pedigree dogs have many advantages because we know their ancestry and can predict the way that they will turn out. This helps us to know how big they will grow, their exercise needs and predict the health problems they might face, enabling breeders to know which DNA tests to give the parents before they are bred from, none of which is available for dogs of mixed ancestry.

"But it also means that they tend to have a more closed gene pool and so we have to manage the rate of inbreeding at sustainable levels to ensure genetic diversity is preserved, as the lower the genetic diversity the greater the risk that certain health conditions will begin to surface.

"The research allows breeders to review the unique situation for their own breed and, using this information and tools such as Mate Select, they can decide how best to preserve genetic diversity, not only for the health of the next litter of puppies, but also for the health of the breed population as a whole."

Caroline Kisko, Kennel Club Secretary, said of the research: "This research has been conducted on a huge scale, but its impact will have a lasting and positive effect on the future of the dog breeds we love so dearly, enablingbreeders touse science to make even better decisions about which dogs to breed from.

"Such analyses are only possible due to the availability of the pedigree data that we hold for every registered dog, and demonstrate the value of this data in helping us to improve the health and welfare of dogs. We remain concerned about those dogs which are not registered with us and about which there is no information, as there is no way of knowing if the breeder is health testing or considering genetic diversity.

"We also remain concerned about crossbreeds such as Labradoodles which are being bred without much of the health information or resources available for pedigree dogs, and which will also have limited gene pools as more and more generations of these crosses are bred."

The research has been distributed to the Breed Health Coordinators for every breed. Judith Ashworth, Kennel Club Breed Health Coordinator for the Otterhound Club said: "We are delighted to receive such comprehensive research to help us preserve the future of our small but historic and wonderful breed. 

"We are working with the Kennel Club to develop breeding strategies that will protect the health of the breed that we love.  With the Kennel Club we have been looking at outcrossing and they have now given us permission to register two litters from a non-purebred dog of a working variety, enabling us to increase the number of dogs that are contributing genetically to the very small population of dogs within our breed. We look forward to working with the Kennel Club to continue to find solutions that will protect the future of our breed."

A peer-reviewed paper outlining general trends and points of interest is available from the online journal Canine Genetics and Epidemiology ( and reports for the 215 breeds are featured on the Kennel Club website as well as a Q&A document and infographics /vets-researchers/publications,-statistics-and-health-results/breed-population-analyses   


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