A double dew claw is a pair of extra toes found on the hind legs of certain dog breeds, sitting higher up on the leg than the regular toes. While most dogs have a single dewclaw on each front paw (similar to a thumb), some breeds carry two dewclaws on each rear leg. These aren’t defects or random mutations. In specific breeds, they’re a defining physical trait that served a working purpose for centuries.
How Double Dew Claws Differ From Regular Ones
Almost all dogs are born with a single dewclaw on each front leg. These front dewclaws are typically well-attached, connected to bone and muscle, and function somewhat like a thumb. Dogs use them to grip bones, toys, and even icy surfaces. They also help stabilize the wrist joint when a dog makes sharp turns at speed.
Double dew claws are a different story. They appear on the hind legs, and a dog with this trait has two extra toes on each rear foot rather than one. In some cases, both extra toes are fully formed with their own bone structure. In others, one or both may be loosely attached, connected mainly by skin and soft tissue rather than a firm skeletal joint. The degree of attachment varies between individual dogs and breeds.
Why Certain Breeds Have Them
Double dew claws are most closely associated with four breeds: the Great Pyrenees, Beauceron, Briard, and Icelandic Sheepdog. All four are herding or livestock-guarding breeds with histories of working in rugged terrain. For these breeds, double rear dewclaws aren’t just tolerated in the breed standard. They’re expected.
The Great Pyrenees historically guarded sheep in the Pyrenees mountains, chasing wolves down steep, rocky slopes. The extra rear toes likely functioned as a braking mechanism on those descents, giving the dog more contact with the ground during high-speed maneuvers on loose or uneven footing. The Beauceron and Briard, both French herding breeds, used their double dewclaws for similar reasons: extra traction while chasing predators across rough ground.
Beyond these four, double dewclaws occasionally appear in other breeds and mixed-breed dogs. When they show up outside the breeds where they’re standard, they’re sometimes called polydactyly, the same term used for extra fingers or toes in any species.
The Genetics Behind the Trait
Double rear dewclaws follow a dominant inheritance pattern. A dog only needs one copy of the gene variant to develop the extra toes. Research has traced the trait to a specific region on canine chromosome 16, within a gene called LMBR1. A regulatory sequence inside this gene controls limb development, and mutations in that sequence cause extra toes to form specifically on the hind limbs. The same genetic region has been linked to polydactyly in other mammals as well.
Because the trait is dominant, it passes reliably from parent to offspring. That’s one reason breeders of Great Pyrenees and Beaucerons have maintained it so consistently over generations. If one parent carries the gene, roughly half or more of the puppies will have the trait.
Grooming and Nail Care
Double dew claws need more attention than your dog’s other nails. The regular nails on a dog’s main toes wear down naturally from contact with pavement and hard ground. Dewclaws sit higher on the leg and rarely touch the ground, so they don’t wear down at all. Without regular trimming, they keep growing in a curved path and can eventually curl back into the dog’s skin.
An ingrown dewclaw is painful and prone to infection. This problem is especially common in long-haired breeds, where thick fur hides the dewclaws and makes it easy to forget about them during routine grooming. Active dogs whose main nails stay short from outdoor play are particularly at risk, because their owners may skip nail trims altogether without realizing the dewclaws still need attention.
You can trim double dew claws at home with the same clippers you use for regular nails. The key is locating the quick, the blood vessel running through the center of each nail. If your dog has dark nails, hold a small flashlight behind the dewclaw to illuminate the quick so you can avoid cutting into it. Trim a little at a time, and file the edges afterward to prevent sharp points that could catch on carpet or furniture. If the nail has already grown into the skin, a vet visit is the safer route for the first trim.
Common Injuries and Problems
The most frequent issue with double dew claws is snagging. Because they protrude from the inside of the leg and don’t sit flush against the ground, these extra toes can catch on underbrush, fencing, carpet, or even another dog during play. A caught dewclaw can partially or fully tear away from the toe, exposing the quick. These injuries tend to bleed more than you’d expect from such a small toe.
Signs of a dewclaw injury include:
- Limping or favoring one leg
- Bleeding from the inner leg area
- Excessive licking of the paw or leg
- Swelling or warmth around the toe
- Flinching or yelping when the leg is touched
Some dogs are stoic and won’t show obvious pain, so it’s worth checking the dewclaws visually during regular grooming even if your dog seems fine. Torn or broken dewclaws typically need veterinary care, and infected or severe cases can cost between $100 and $300 to treat, sometimes requiring minor surgery.
Should Double Dew Claws Be Removed?
This is one of the more debated questions among dog owners and veterinarians. For breeds where double dewclaws are part of the breed standard, removal would disqualify a dog from conformation showing. Beyond that, well-attached dewclaws that have bone and joint connections serve a functional purpose, and removing them means removing part of a working digit.
Loosely attached dewclaws that dangle and have no bone structure are more vulnerable to snagging and injury. Some veterinarians recommend removing these in puppyhood, typically when the dog is already under anesthesia for spaying or neutering. The procedure is simpler in young puppies, when the tissue is less developed.
For most dogs with double dew claws, the practical answer is straightforward: keep the nails trimmed, check them regularly for damage, and leave them alone unless they’re causing repeated problems. Dogs that work in dense brush or rough terrain may face a higher injury risk, but for the average household pet, consistent grooming is enough to prevent the most common complications.