Clara Medalen 
Playing with nature is a hallmark of human existence. We believe we can take the products of evolution and make them better with our limited knowledge of physiology. But are we really just disrupting the stability of the body as a whole? It was not so long ago that doctors were surgically removing healthy appendices and tonsils, only to learn that they play an important role in the immune system. Yet we are unable to learn from past mistakes and insist on classifying body parts as vestigial when we are ignorant of their true function. And so we as a species continue to modify with an inexpert hand, not only our own kind but to a larger degree the animals we care for. People do not realize the consequences of removing structures such as the distal phalanx of cats, docking tails, cropping ears, spaying or neutering prior to puberty, or taking off a dog’s dewclaw. These practices may or may not be beneficial to the animal overall, and as vitalistic doctors, it is time we take a deeper look into the pros and cons of such body modifications.
The practice of removing dewclaws is done at 2-5 days of age, preferably day 3. The practice is standard for show dogs, and this practice has bled over to the world of companion dogs. It is argued that it prevents future injuries to the dewclaw as they are commonly torn in active dogs. However, the surgery is done without anesthesia on fully developed nerve endings. The procedure can be done later during a spay or neuter surgery, but this causes more problems as the leg is easily accessible to the dog even with the use of a cone. Oftentimes the area needs to be re-stitched and antibiotics administered. Injury to the dewclaw is most often a maintenance issue, as they tend to grow faster than other claws because they are not worn down naturally and many owners forget to trim them. A long dewclaw is more likely to catch on things or become ingrown (1).
There are five tendons that attach to the dewclaw – one more tendon than the human thumb, one of the most important evolutionary developments in dexterity that has allowed humans to become the most adaptable and dangerous predator on earth. So why do we think there is no function to a dewclaw? The removal of dewclaws severs the anchor of five muscles, leading to atrophy of the foreleg and destabilizing the entire kinetic chain (2). Dogs and other four-legged animals carry 60% of their weight in the front legs and only 40% in the hind legs. Vertical forces on the front limbs are therefore much greater, approximately 4 1/2 times the body weight on impact at high speeds. It is no surprise, then, that osteoarthritis is five times more common in the metacarpals than the metatarsals of agility dogs (3).
When standing, the dewclaw sits above the other digits, not contacting the ground. During activity, such as cantering or galloping, the dewclaw is dug into the ground, preventing toque and stabilizing the lower leg. Without a dewclaw, forces exerted from quick turns are instead distributed to the rest of the leg (2). Removing dewclaws routinely has consequences including an increased prevalence of injury to the rest of the body. In a study done on 3,801 agility dogs, it was recorded that ⅓ will experience more than a single injury in the course of their career. Of those injuries, 13-24% are injuries to the phalanges. Another study on 253 agility dogs showed that digit 5 was the most commonly injured digit while digit 1 (the dewclaw) was the least often injured. Increased injury to digits 1-4 were seen in dogs lacking front dew claws. Other injuries reported were to the shoulders, back, and neck (3).
Dewclaws are a vital structure providing greater stability to the anterior kinetic chain of canines. While removing the dewclaws of a dog can potentially prevent injury directly to the structure, it can lead to injuries of the structures around it. It is a sacrificial area meant to protect the body as a whole, and the early loss of the dewclaws leads to instability for the remainder of the animal’s life. As vitalists, we see the body as a connection of parts necessary to the overall health of an organism. As such, I call on you all to take a stand against the removal of vital body parts without due cause.
References
- Lichtenberg D. Dewclaw Removal in Dogs: When Is It Necessary? (Vet-Approved Advice) [Internet]. Petful. 2019 [cited 2019Oct13]. Available from: https://www.petful.com/pet-health/dewclaw-removal-dogs/
- Zink C. Do the Dew(claws)? Canine Sports Productions [Internet]. 2013 [cited 2019Oct13]; Available from: https://www.caninesports.com/uploads/1/5/3/1/15319800/do_the_dew__claws__rev_apr_10_2013__with_logo_.pdf
- Sellon DC, Martucci K, Wenz JR, Marcellin-Little DJ, Powers M, Cullen KL. A survey of risk factors for digit injuries among dogs training and competing in agility events. Journal of the American Veterinary Medical Association [Internet]. 2018 [cited 2019Oct13];252(1):75–83. Available from: https://escholarship.org/content/qt50v4f8gx/qt50v4f8gx.pdf
This article first appeared in the November 2019 issue of Lifelines, the Life West student magazine.