The story of the Norwegian Lundehund serves as a striking example of the outer consequences of inbreeding – an issue that many breeds, such as the Airedale Terrier, are dangerously close to. With a gCOI (Genomic Coefficient of Inbreeding) of, on average, 38%, Airedales are already one of the most inbred breeds in the dog world. While this figure is not as extreme as the Lundehund’s, it still raises serious concerns about the breed’s future health and genetic diversity. The Lundehund’s history remains a powerful reminder of the consequences that come with severely reduced genetic variation.

The Norwegian Lundehund, an ancient and unique breed, has a fascinating yet fragile history. Known for its extraordinary agility and physical adaptations, such as six toes on each paw, remarkable flexibility, and the ability to close its ears, it was traditionally used to hunt puffins along Norway’s rugged coast. However, by the early 20th century, as puffin hunting declined, so did the need for the Lundehund, and its population declined.

The breed faced its greatest crisis during World War II when a distemper outbreak wiped out the already small Lundehund population. By 1963, only six dogs remained, all closely related, leading to severe inbreeding. This genetic bottleneck resulted in an extreme lack of diversity, which is reflected in the breed’s current gCOI at 90%. This means that 90% of the genes within the Lundehund population are identical by descent, a figure far higher than many other breeds like the Airedale, whose 38% gCOI on average is still alarmingly high. For the Lundehund, this high inbreeding level has led to severe health issues, most notably Lundehund Syndrome, a genetic disorder affecting the digestive system.

The Rescue Plan: The Incross Project

To address these challenges, the incross project was initiated in 2014. This project aimed to expand the gene pool by introducing new bloodlines from related breeds, such as the Norwegian Buhund, Icelandic Sheepdog, and Norrbottenspets, while preserving the Lundehund’s unique traits. The primary goal of the project was to reduce the high levels of inbreeding, which were directly responsible for many of the health issues plaguing the breed.

According to recent findings summarized in a 2022 study by Melis et al., the incross project has focused on carefully selecting individuals from the related breeds to maintain the Lundehund’s key characteristics while introducing much-needed genetic diversity. The project has adopted a long-term perspective, ensuring that crossbreeds are reintegrated into the Lundehund population over multiple generations. Importantly, the initial results of these crosses have shown promising signs: early generations of crossbred dogs have displayed improved health, particularly in areas like digestive function and overall robustness, compared to the highly inbred Lundehund line.

Results and Ongoing Work

The early results of the first crosses have demonstrated increased genetic diversity and reduced occurrence of Lundehund Syndrome in the offspring. Furthermore, these dogs have largely retained the distinctive traits of the Lundehund, such as their flexibility and extra toes, proving that the incross project can maintain the breed’s unique characteristics while improving its overall genetic health. The long-term goal is to gradually reintegrate these crossbred dogs back into the Lundehund population, eventually lowering the gCOI and improving the breed’s resilience.

The project also highlighted several critical points for breed rescue:

  • Genomic mapping has been essential for tracking genetic diversity and ensuring that introduced genes positively influence health.
  • Crossbreed management is crucial; not every cross can be considered successful for reintegration, so selective breeding has been used to ensure the health and traits of the Lundehund are preserved.
  • Collaboration between breeders and geneticists is key to monitoring health outcomes and making data-driven decisions to guide future breeding programs.

A Cautionary Tale for Other Breeds

Although the Lundehund remains rare and its gCOI is still significantly high, the outcross project has shown promise in improving the overall health and longevity of the breed. Breeders continue to carefully manage this balance, ensuring the survival of this remarkable breed while maintaining its distinctive features. Today, the Norwegian Lundehund stands as a symbol of resilience, with its 90% gCOI a reminder of its unique and endangered genetic heritage. Its story serves as a cautionary tale for highly inbred breeds like the Airedale Terrier, underscoring the need for careful genetic management to avoid similar outcomes.

This rescue effort illustrates how planned crossbreeding and modern genetic tools can offer a pathway to healthier future generations, not only for the Lundehund but for many breeds threatened by inbreeding.

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Note: This text was initiated and written by the author, with AI tools used to enhance language and readability. 
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References

Published on the Facebook group European Airedale breeders, September 19, 2024 (link) 

Photo by Norsk Lundehund Klubb