Dewclaws - A Digit To Keep!
Dewclaw removal is not uncommon and is often performed in puppies to prevent future injury, but does this really prevent injury? For the dewclaws which are also gone then yes, they are not going to get injuries, but there is increasing evidence that removing these appendages can increase the risk of injuries to the dog - either in other areas or around the site of removal. Let’s look at why this might be.
Dewclaws
Dew claws are the small thumb-like structures on the feet of dogs and can be found most often on the front feet, but occasionally also on the hindlimb. Sometimes the hindlimb dewclaws are what I like to term ‘dingly dangly’, or vestigial dewclaws, held on by just a small envelope of skin. Some breeds naturally have them on their hindlimb, such as the Saint Bernard, Pyrenean Mountain Dog, Briard, Anatolian Shepherd Dog and the Catalan Sheepdog.
When the dog is in a standing position, these dewclaws appear non-functional because they are not in contact with the ground. However, we now recognise that dewclaws on the front feet do have a functional role for the dog and their presence is beneficial. They are firmly attached to the dog on most cases, just as our thumbs are, and make up part of the wrist joint, also known as the carpus or carpal joint. There are muscles attached to them via the muscle’s tendon, and these help minimise rotation of the front leg when turning. When watching a slow motion video of a dog running and especially turning, it can be seen that the dewclaw makes contact with the ground and supports the carpus, putting less pressure through this joint and providing more stability as the nail digs into the ground. In addition, when a dog is climbing up out of a river, or up a bank, these help grip into the ground and facilitate the movement upwards. They also have a role of helping to grip toys or chews when the dog holds these items between its front feet.
Removal of these digits as newly born puppies (usually done at the vets with a pair of small scissors and no anaesthetic, as the bitch is taken off for a walk) is not infrequently performed, the argument being that for working dogs in particular this digit often gets injured and then necessitates a full surgery to remove at that time. Some breeders who compete in conformation feel that removal of the dewclaws makes the legs appear straighter when viewed form the front. However, we are beginning to recognise that removing this functioning digit can lead to long-term issues, most notably the development of carpal osteoarthritis due to the reduction in support for this joint. The lack of dewclaw means there is more potential for the carpal ligaments to stretch and tear, and lack of stabilisation against rotation of the carpal joint can lead to laxity and excess movement of the bones in the carpal joint. The length of the nail of the dewclaw can also play a role in the chances of damage to this digit, with the longer the nail, the more chance of it being caught and damaged, or damaging the rest of the digit with the shearing force of being caught during movement. As always, short nails are a good thing, and in this situation play a role in reducing risk to this digit.
So should we be removing this dewclaw digit or not? My feeling is that routine removal of front limb dewclaws in puppies is not the correct way forward. Instead, we should be ensuring the nail itself is kept short and monitoring for any injury. What seems like a quick fix and avoidance of injuries longterm for this newly born puppy, done with the best of intentions by the breeders, may actually exacerbate the potential for longterm chronic disease in the area - that of potential arthritis in the carpal joint. However, the caveat needs to be made that for vestigial or ‘dingly dangly’ dewclaws with no bony attachment to the rest of the limb, and therefore unable to provide any support, it may be better to remove them to avoid injury. Removal of dewclaws for cosmetic reasons, or to meet breed standards is, in my professional opinion, not appropriate and instead we should be changing breed standards.
