The Norwegian Lundehund is a fairly small, rectangular, Spitz-type dog that has unique structural traits not found together in any other breed. They were developed to wrestle and retrieve Puffin chicks from cracks and crevices of vertical seaside cliffs on remote islands of northern Norway. As they evolved over the centuries, Lundehunds acquired a number of unusual anatomical attributes that enabled them to climb, descend and remain sure-footed on slippery cliffs and in tight tunnels, making them especially well-suited for their Puffin-hunting chores.
Lundehunds have six digits on each front foot: five fully-developed triple-jointed toes and one double-jointed toe that resembles a human thumb. Most of the toes on the Lundehund’s hind feet are also triple-jointed. Other domestic dog breeds normally have only four functional toes per paw, and possibly one or two non-functional dewclaws. Having extra toes is called “polydactylism.” Polydactylism was selectively bred into this breed to enhance its grip and stability on the steep, slippery cliffs where Puffin colonies nested. Lundehunds also have eight foot pads on each of their front paws and seven on each hind foot, which is more than that of other breeds. This unique foot structure enables the Lundehund to get tremendous traction in tight spaces and to support and brace itself on uneven or unstable terrain.
Lundehunds have double-jointed necks that enable them to bend their head backwards, up and over their shoulders, so that their forehead actually touches their spine. This anatomical adaptation was extremely useful when the dog needed to squeeze into or turn around in narrow Puffin passageways, so that it could bring its precious prey home. Among mammals, only the reindeer reportedly has similar flexibility in its neck and upper spine.
Lundehunds’ shoulders are extraordinarily flexible. Their shoulder joints are elastic enough that their front legs can stretch straight out to the sides, at ninety-degree angles. This helped them “throw out their arms” and “hug the cliffs” when they lost footing on slippery slopes or had to shift in cramped quarters. Lundies basically can do the splits with their front legs without discomfort. This unusual shoulder conformation contributes to a peculiar rotational front-end movement when Lundehunds are gaiting.
Probably because Lundehunds were developed in a wet, rainy climate, they developed the unusual ability to close their naturally upright ears at will by either folding them forward or backward, leaving only a little space open on the outermost side of the ears for hearing. This adaptation protected their sensitive ear canals from moisture, dirt and other debris. It may also have helped Lundies’ orient themselves in tight spaces.
Today's Lundehund has the same jaw as the ancient Varanger Dog, which is a now-extinct fossilized dog found in north Lapland, Russia, dating back more than 5000 years. Both of these breeds have one less tooth, on both sides of their jaws, than other domestic dogs. The reason for this adaptation is not clear.
The Lundehund displayed on all the pictures is Lundeklippe Svarri.