Miley’s front foot is very typical of a dog foot. It’s designed for running long and hard over open ground, but you’ll note that she does have dewclaw on the foot.
Because dogs are digitigrade, it looks like her dewclaw is half way up her wrist, but that’s not actually her “wrist” at all. That’s the part of her foot that doesn’t touch the ground.
Although dogs do use their dewclaws, their exact utility is pretty limited. They can’t grab things with them, and in many breeds, it is still traditional for people to remove them on very young puppies. It’s done to prevent tearing, which is actually a pretty rare occurrence, even among dogs that still have their dewclaws on the front legs.
All species of dog have dewclaws on the front legs, except for the African wild dog. It is so well-adapted to cursorial hunting, that the dewclaw has already disappeared in that species.
But where would such digit come from?
Well, if you really want to know, you better understand evolution.
Just as the big toe on humans is a severely modified great ape “thumb,” the dewclaw started out as a fully functional fifth digit.
To understand this a bit better, one must look at an animal that retains many features of the primitive carnivorans.
Probably the best example I can think of is the kinkajou. Kinkajous are procyonids that are almost entirely arboreal in their habits, and in this way, they strongly resemble the ancestral carnivoran in both habits and phenotype.
Indeed, they are so primitive in appearance that their bodies actual remind meany people of very primitive primates, which led many people to deem the kinkajou a type of monkey. In some Latin American countries, kinkajous are still called “night monkeys.”
And they actually look more like some kind of primate than many lemurs and bush babies do! That’s because if you go far back enough in the lineage of placental mammals, you will find ancestral arboreal animals that look something like this.
Kinkajous and dogs last shared a common ancestor some 40 or 50 million years ago. Their common ancestors were creatures called miacids, and these particular miacids were the ancestral caniforms. The big split in caniforms happened the dog family split off from the rest to go chasing things on the ground.
The ancestors of kinkajous stayed in the trees, and as predators, they are pretty poor at the game. Indeed, they live almost exclusively on fruit and nectar from flowers.
In the trees, their feet have never undergone the selection pressures that have made the dogs’ running shoes. Their feet have stayed very much like those primitive carnivorans.
In the photo above, you can see that a kinkajou has hands that almost resemble our own. They can actually grab things and hold them in those hands, as you can see in this video:
Although dogs can turn door knobs with their paws, they really can’t grab things in quite the same way.
Now, dogs have certainly not gone as far as horses have on their digitigrade anatomy. Horses run around on a single toe with a very hard and thick nail on it.
But they have lost their ancestral hands.
Their feet are now runner’s cleats.
The only vestige that they were once designed quite differently is that dewclaw.
And even if dewclaws are not entirely useless, they aren’t nearly as functional to a dog as that fifth digit is to a kinkajou.
In retrospect, it’s probably a good thing dogs don’t still have those kind of feet. Just imagine what kind of trouble they could cause if they were able to manipulate objects as well as a kinkajou can!
Though well down the evolutionary road to losing that fifth toe totally, most dogs still use their dewclaws to some extent, especially if they’re an active working animal rather than a family pet who is mostly a couch potato (and before people start screaming that I’m anti-pet, let me say there’s nothing wrong with couch potatoes, and a dog just being a pet in general. Most of my dogs are both most of the time). When I actively hunted with coon hounds, my hounds would actually climb trees using their dewclaws exactly like a thumb. They wouldn’t grasp branches like we would, but they’d wrap their forelegs around a truck and push themselves up with their hind legs, and it was mostly their (front) dewclaws that gave them a grip on the trunk. Also, when fighting another animal of nearly their own size (whether its a coursing hound taking on a wolf-like coyote, or a small terrier killing a big rodent), those dewclaws come in very handy. As far as I can see, the main “use” of a dewclaw is to give the dog purchase in the opposite direction of the other four toes in unusual situations (even a running hound will grasp with them when they’ve slipped sideways and gone down and are trying to regain traction and get back up. When my wolfhounds slip when making a turn, they keep on digging in and running, even though they may be on their sides briefly, and never just stop and get back up and begin running again, it all happens in one continuous motion. When I check the spot where they went down I can usually see a long gouge in the ground where the dewclaw on their top side leg dug in to help stop their slide and get them going again).
I never remove the front dewclaws from a dog, and as I’ve stated previously, I think the main reason many breeders do is because puppies and dogs scratch people with them, so they remove them and make up myths as to why it must be done. It sounds much better if you claim you’re cutting a dogs thumb off for their benefit rather than yours.
You are really on a roll buddy–another excellent piece.
My tazi (saluki) uses his dewclaws whenever he runs at speed or executes a turn.
If you don’t think dewclaws are used, here’s a test. Check to see if the nails wear down more slowly on the dewclaw than on the others. If not, it’s getting just as much wear as they are.
Where do dew claws come from?
From the dewclaw fairy, of coarse!
Or from trimming your pet’s toenails when he is sleeping in bed.
One of the toenail clippings falls under the dog’s pillow, a fairy comes along and assumes that the dog must have lost a toe that day, and so gives the dog a new one, but since the dog never really lost a toe to begin with, the dog now has an extra toe, and gifts from fairies can be inherited.
Marilyn Monroe is said to have had 6 normal looking toes on each foot. Guess the toe-fairy must of liked her!
There is an excellent video example of how dogs use dewclaws in “From Tongue To Tail” – (available in the GRCA store). Under normal activity the dewclaw does not touch the ground but in a turn or when climbing, it is used very effectively. And if you have ever seen those videos of the Goldens who hate the teeter in agility – you will see them hanging on for dear life with their dewclaws. The additional reason we would never remove them is that it is the acupuncture point of Stomach 4 which is used to relieve hiccups and in a bloat emergency.
Kyuss doesn’t have dews. His breeder removed them, with his tail when he was 2 days old.
I had hears of people saying their dogs injured their dewclaws before, but it was always hearsay; until a few weeks ago. A friend of mines dobie actually injured his dewclaw. He tore it pretty good, but the vet was hopeful it would heal with a few stitches and not have to be removed.
Had Kyuss had his dews and he had injured them, I would probably have done the same (stitch it and let it heal) but if it was continual I would have them removed.
I’ve heard of young boys injuring their penis in a zipper.
Was this directed in response to me?
Hi pennypup,
In case your question is directed at me, since my comment is above yours, I thought maybe I should explain my comment, I was being more funny than clear, wasn’t I?
More clearly: I wouldn’t advise going around cutting off body parts just because they might get hurt sometime in the future.
People lop off dog’s ears, tails, and dewclaws, then try to justify it by saying that these parts, if left on the dog, might get injured. But maybe it would be better to wait and see if these parts get injured, and then decide if they need to be lopped off.
Pennypup: that doesn’t seem to disagree with what you wrote, so if I’m butting into a conversation, please excuse me, but you left it unclear who your question was directed to.
Myself, and some others, start comments that are mostly for one person with something like “Hi pennypup”, feel free to copy the “Hi……” , I didn’t start it, paper letters also had such forms of address so I would seriously doubt a copyright on it.