By Jennifer Coates, DVM
Take a look at your dog’s feet. How many toenails do you see? Most dogs have four nails on each rear foot and five on their front feet. That extra nail on the upper, inner part of a dog’s foot is the dewclaw. Did you come up with a different total? Have no fear, some dogs have dewclaws on their rear feet or even double dewclaws. Read on to learn if your dog’s dewclaws might pose a potential problem and what you can about it.
What are Dewclaws?
Dewclaws are essentially the thumbs and big toes of the dog world. They are not directly equivalent to the human structures, of course, but they are similar. Looking at a dog’s front foot, the toes that are in contact with the ground while standing correspond to our pinky, ring finger, middle finger, and index finger. The dewclaw is the “thumb.” The same is true for the canine hind foot with the dewclaw being the “big toe.”
An important distinction to make is whether or not the dewclaws are firmly attached to a dog’s foot. In general, if your dog has a single front dewclaw, it will be. You’ll be able to wiggle the dewclaw a little bit (mostly in a forward and backward motion), but you can feel the bones that connect it to the leg. Rear and double dewclaws tend to only be attached by skin and are much more mobile.
Do Dewclaws Have a Purpose?
A dewclaw that is attached by bone to a dog’s front foot has a definite purpose. When dogs run, their front feet often bend to the point where their dewclaws come in contact with the ground. At high speeds (especially when turning) or on slippery surfaces, these dewclaws provide extra traction and help stabilize the carpal (wrist) joint. Some dogs also use their dewclaws to help them climb trees, hold objects to better chew on them, or climb out of the water if they’ve broken through ice. The usefulness of dewclaws that are only attached by skin is less clear.
Should Dewclaws be Removed?
Because front dewclaws serve an important purpose, they should not be removed unless there is a very good reason to do so. In rare cases, a dog’s dewclaw may be severely injured or develop a disease (e.g., a cancerous tumor) and removal under those circumstances would certainly be in the dog’s best interests. These problems occur so infrequently, however, that removing healthy front dewclaws to prevent them makes little sense.
It is more common for veterinarians to remove loosely attached double or rear dewclaws to prevent injury. The actual incidence of these types of injuries is still quite low, so the value of these surgeries is up for debate. Typically the surgery is scheduled at the same time the dog is being spayed or neutered (while it is anesthetized).
Some breeds of dogs routinely have their dewclaws removed to “improve” their appearance in the show ring. If you choose to have this procedure performed it should done when a puppy is under 5 days of age and only after the area has been numbed with a local anesthetic (e.g., EMLA cream).
Keep in mind that removing the dewclaws in other breeds, like Great Pyrenees, disqualifies them from the show ring.
Treating Dewclaw Injuries
While dewclaw injuries are relatively rare, they certainly do occur. Any nail can become partially or completely pulled off, broken, split, infected, or ingrown (if not properly trimmed). Since most nail injuries are extremely painful and prone to infection (think of all the places your dog’s feet have been!), it is usually best to have them assessed by a veterinarian. He or she can remove damaged nails or trim ingrown ones (under sedation, if necessary), and prescribe any needed antibiotics and pain relievers.
How to Maintain Dewclaws
When it comes to maintenance, dewclaws are no different than your dog’s other nails. Dogs who are extremely active may wear down their nails, including their dewclaws, to the point where nail trims are not necessary. But for most pets who are relatively sedentary, regular trims are needed to keep their nails at a healthy length. Keep an especially close eye on the dewclaw. Since they are not in contact with the ground as frequently as the other nails, they may require more frequent trims.