Sometimes, dogs have thumbs. No, really. In dogs, a dewclaw is an extra digit found in the ‘thumb’ position of their front paws. A dewclaw includes toe bones, muscles, claw, and a tiny paw pad. Occasionally, dewclaws can be found on a dog’s back feet. Other dogs are polydactyl—that is, they have multiple extra toes.
In prehistoric times, a canine ancestor known as Miacis climbed trees using five retractable claws. This ancestor’s 5-clawed genes still appear in modern dogs, 40 million years later!
A dewclaw is a dog thumb
Not all dewclaws are completely formed, however. They can range from handy—great for gripping bones and toys—to useless, floppy claws barely attached to muscle or bone. These loose claws can be a source of injury and pain for active dogs, as they may stick out at an angle, and not be held close to the paw without fully developed musculature.
The dewclaw usually doesn’t get worn down by regular exercise. Therefore, it can grow awkwardly long before an owner notices it, or become ingrown, causing acute pain and requiring surgery to remove.
Some dog breeders remove the dewclaws of puppies as a matter of routine. Whether this is painful and unnecessary or a proactive benefit is a matter of serious debate. Older dogs may require the removal of dewclaws occasionally, due to repeated injury.
If the dewclaws on your dog’s front or rear paws seem to easily get caught on things, then they could easily rip off — which would be very painful for the dog. In this case, you should talk with your vet about whether or not to have the dewclaw(s) removed. This is a before and after!
A photo posted by @pet.wellness on
If you’re concerned about your dog’s dewclaws, it’s always a good idea to consult with your vet.
Otherwise, enjoy this little oddity of dog anatomy for what it is: a quirk of history.
Featured image: © Eakkluk Aumaon | Dreamstime.com – Handshake with white dog