Double dewclaws are specialized digits located on dogs' hind legs, positioned higher than regular toes and considered the evolutionary equivalent of thumbs. While most dogs have single dewclaws on their front legs, only specific breeds genetically inherit double dewclaws on their rear legs. These unique anatomical features serve functional purposes - providing enhanced grip on rough terrain, supporting climbing abilities, and aiding in swift directional changes during activities like herding. Found predominantly in mountain and herding breeds like the Great Pyrenees and Beauceron, double dewclaws are a distinctive trait requiring proper maintenance for the dog's optimal health and mobility.
Double Dewclaw Breeds
Breed Characteristics
The Great Pyrenees, Briard, Beauceron, and Icelandic Sheepdog are notable breeds that characteristically have double dewclaws on their hind legs. In these breeds, the double dewclaws are considered part of their breed standard and serve functional purposes.
Anatomical Structure and Function
Double dewclaws contain bone structure and muscle attachments in breeds like the Great Pyrenees, making them fully functional digits rather than vestigial appendages. These specialized adaptations help the dogs navigate challenging terrain - the Great Pyrenees uses them for mountain climbing stability, while herding breeds like the Briard utilize them for quick directional changes. The Norwegian Lundehund represents an extreme case, possessing up to six fully formed toes per foot to aid in scaling cliffs.
What are Double Dew Claws and Their Function
Structure and Location
Double dewclaws consist of two extra digits positioned higher up on the hind legs compared to regular toes. While single dewclaws are common on front legs, double dewclaws specifically refer to paired claws on rear legs that are typically attached by skin rather than bone in most breeds.
Evolutionary Purpose
Double dewclaws served as an ancient adaptation that developed to provide additional stability and grip. Unlike wolves and wild canids that lack these digits, domesticated breeds developed them through selective breeding. In sporting and working dogs, they aid in activities like agility trials by helping dogs grasp obstacles and maintain balance during quick directional changes. The dewclaws also assist in gripping bones and toys between the front legs and provide extra traction on slippery surfaces like ice or when climbing out of water.
Dog Breeds with Double Dew Claws
Rare Breed Variations
While the Norwegian Lundehund represents an extreme case with up to 6 toes per foot, other rare breeds like the Saint Bernard also possess double dewclaws. Unlike the previously discussed common double dewclaw breeds, these variations developed the trait for specific working purposes - the Saint Bernard's dewclaws provided additional stability when performing rescue work in snowy Alpine conditions.
Genetic Expression Patterns
The presence of double dewclaws is essentially genetic and varies in expression between breeds. While the earlier sections covered functional aspects, this trait manifests differently across breeds - some have fully formed, bone-attached dewclaws while others display "floating" dewclaws attached only by skin. This genetic variation influences both the dewclaw's functionality and the need for specialized care in different breeds.
Double Dew Claws Breeds
Health Management
While previous sections covered functional aspects, proper maintenance of double dewclaws requires specific care. Since these nails don't regularly contact the ground, they tend to grow faster than other nails and need more frequent trimming to prevent snagging and breaking. Veterinarians recommend running a finger under the nail to check for excessive length - if it catches, trimming is needed. Infections and injuries are also considerations, potentially requiring antibiotics or surgical intervention in severe cases.
Surgical Considerations
Unlike standard dewclaw removal, double dewclaws should typically be preserved in breeds where they're standard. While some veterinarians suggest removal, particularly for dewclaws only attached by skin, this practice is discouraged in breeds like the Great Pyrenees where the feature is functional. Surgical removal should only be considered if medically necessary, as these digits can help prevent limb twisting and injury during activity.
Conclusion
Double dewclaws are a distinctive anatomical feature found in several dog breeds, most notably the Great Pyrenees, Briard, Beauceron, and Icelandic Sheepdog, where they are considered part of the breed standard. These extra digits contain bone structure and muscle attachments in certain breeds, making them functional rather than vestigial appendages that aid in activities like climbing, herding, and maintaining stability on challenging terrain.
The research highlights the genetic nature of double dewclaws and their evolutionary purpose in providing additional grip and balance. While some breeds have fully formed, bone-attached dewclaws, others have "floating" ones attached only by skin. Proper maintenance through regular nail trimming is essential, and removal is generally discouraged in breeds where double dewclaws are standard unless medically necessary. These findings emphasize the importance of understanding breed-specific traits and providing appropriate care to maintain the health and functionality of these specialized anatomical features.