Why Are Norwegian Lundehund so Rare?
If you never heard about the Norwegian Lundehund, don't feel bad. This dog breed is rare as much as it is unique.
Realistically, how many dog breeds can you name that have six toes, are capable of folding their ears and are blessed with an amazing flexibility which allows them to bend their head backwards, up to the point of touching the spine?
No, this is not a joke. This dog breed really exists and is like no other. Discover more about the Norwegian Lundehund and why this dog breed has become so rare.
A Passion For Puffins
To admire the Norwegian Lundehund in all its natural beauty, you will need to travel back in time to the rugged coastal cliffs of Norway where this dog breed called his home.
Here by the treacherous cliffs, this four-legged acrobat was often found hunting for puffins and their eggs. If you have never heard about puffins before consider that they are charming seabirds with brightly colored beaks and striking facial markings.
This dog breed's name ultimately derives from these birds. Just consider that, in Norway, the word "lunde" means puffin, while the word "hunde" instead means dog.
A Lundehund's history for hunting puffins goes as far back as 1600. Back in the days, this bird's meat was used for food and their feathers were used to make feather beds that were often exported to nearby locations.
Why Are Norwegian Lundehund so Rare?
While Lundehunds were used for many centuries to hunt puffins, their numbers have sadly declined dramatically as nets for hunting the birds were crafted in 1850 and puffin birds became a protected species.
To make matters worse, several outbreaks of canine distemper taking place during World War II, and then again, in 1963, further decreased their numbers to only 5 highly inbred specimens.
Due to two genetic bottlenecks (reduction in population size) taking place in the 1940s and the 1960s this breed has suffered from a significant decrease in genetic variability.
When there is a low population size, there is decreased genetic variability which leads to inbreeding depression. Inbreeding depression is associated with smaller litter sizes, reduced fertility and problems with mating behavior.
Nowadays, their numbers have risen and there were an estimated 1500 Lundehunds world-wide (about 900 live in Norway), but all of them appear to ultimately descend from only two individuals.
Lundehund Syndrome
To make matters worse, Norwegian Lundehunds are predisposed to a medical condition known as "intestinal lymphangiectasia," a protein-losing enteropathy that known for causing intermittent diarrhea, vomiting, weight loss and ascites. This condition has been nicknamed “Lundehund syndrome."
In addition, Lundehund syndrome predisposes Norwegian Lundehunds to chronic atrophic gastritis and gastric cancers.
Due to these conditions, breeders advise new owners to feed their dogs a diet low in fat content.
Despite taking preventive measures, studies on mortality rates of Norwegian Lundehunds revealed that 30 percent of deaths occurring prior to the age of 11 were due to Lundehund Syndrome, while other 10 percent were due to other gastrointestinal diseases.
While Lundehunds were used for many centuries to hunt puffins, their numbers have sadly declined dramatically
Outcrossing to Increase Genetic Diversity
Because the few specimens remaining are highly inbred, experts have been considering outcrossing, which is the technique of crossing between different breeds, for the purpose of increasing genetic diversity.
Currently outcrossing is taking place with Norwegian Lundehunds being crossed with three other Nordic Spitz breeds: the Norwegian Buhund, the Icelandic Sheepdog, and the Norrbottenspets.
The strategy of increasing the genetic diversity of small, inbred populations by introducing new individuals is often known as "genetic rescue."
While this strategy can be helpful in increasing genetic variability, improving fertility and reducing the occurrence of Lundehund Syndrome, there are also certain risks involved.
Concerns include impacting the "purity" of the breed, losing breed-specific traits and introducing “new” genetic diseases, although it is also true that genetic disorders are less likely when a diverse, gene pool is maintained.
Foot of a Norwegian Lundehund, notice the six toes
The First Crosses
The first crosses of the outcrossing project involved mating a male Lundehund with a female Buhund. This choice was made because the Buhund breed weighs 12 to 18 kilograms, whereas a Lundehund weights 6 to 9 kilograms.
Both the Lundehund and Buhund individuals were unrelated by pedigree for at least three generations.
The Buhund specimens included in the project were also required to have grade A or B hip dysplasia (HD), grade 0 patella luxation (dislocated kneecap) cleared free of any hereditary eye disorders, have a good temperament and overall, a good state of health.
The first two litters of Lundehund × Buhund crosses (F1 generation) were born in 2014. The offspring were then mated back to the Lundehund (F2 generation).
These second-generation crosses showed all the desirable Lundehund breed specific traits, such as polydactyly, foldable ears and joint flexibility. There were also no F1 and F2 specimens showing signs of developing Lundehund Syndrome so far.
At this point, the process of outcrossing has appeared to exert beneficial genetic effects in a highly inbred and rather rare dog population.
While backcrossing the F1 generation back to the parental population resulted in a loss of heterozygosity, which was seen in the initial outcross, the F2 generation (made by crossing the F1 with the Lundehund), demonstrated a return of the main characteristics of the Lundehund.
A: Norwegian Lundehund, B. Buhund, C: F1 first generation crossing D: F2 second generation crossing Photo credits: (a): Dagrunn Mæhlen, (b): Ina Margrethe Gabrielsen Egren, (c): Cathrine Brekke,(d) Arild Espelien.
References:
- Stronen AV, Salmela E, Baldursdóttir BK, Berg P, Espelien IS, Järvi K, Jensen H, Kristensen TN, Melis C, Manenti T, Lohi H, Pertoldi C. Genetic rescue of an endangered domestic animal through outcrossing with closely related breeds: A case study of the Norwegian Lundehund. PLoS One. 2017 Jun
- Melis C, Pertoldi C, Ludington WB, Beuchat C, Qvigstad G, Stronen AV. Genetic Rescue of the Highly Inbred Norwegian Lundehund. Genes (Basel). 2022 Jan
- Kropatsch R, Melis C, Stronen AV, Jensen H, Epplen JT. Molecular Genetics of Sex Identification, Breed Ancestry and Polydactyly in the Norwegian Lundehund Breed. J Hered. 2015 Jul-Aug
Disclaimer: this article is not meant to be used as a substitute for professional veterinary advice or behavioral advice. If your dog is acting sick or aggressive please consult with a qualified professional for proper diagnosis and treatment.
