Among the variety of bones your dog has, the carpal bones are particularly important, and something to be aware of especially if you are the owner of a performance dog who is engaged in various doggy sports. Your dog's carpal bones are known for forming several joints. A joint is simply the place where two bones meet and allow movement. Joints typically consist of bones, muscles, ligaments and cartilage, and in order to stay flexible and well working, they are lubricated with joint fluid. So today, let' s discover a thing or two about the dog's carpal bones, their role in movement and the medical conditions these bones may be subjected to.
Introducing Your Dog's Carpal Joint
Hello, it's us, your dog's carpal bones talking! We consist of several small bones that make up your dog's wrist. Our name indeed derives from the Latin word "carpus" meaning wrist.
What bones are we? There are actually seven of us, strategically aligned in two rows, parallel to each other. The ones displayed on the first top row are given individual names; whereas, the ones on the bottom row are given numbers rather than names.
Here is the list of our names: radial carpal bone, ulnar carpal bone, accessory carpal bone, first carpal bone, second carpal bone, third carpal bone and fourth carpal bone.
We are basically located in between the lower portion of your dog's radia and ulnar bones and the top of the metacarpal bones. We work together to form three articulations; your dog's antebrachiocarpal joint, the middle carpal joint, and the carpometacarpal joint.
"Each bone of the carpus has a convex or concave side that matches a curve on the adjacent bone. These seven bones fit together like fieldstones that are used to build the walls of a house. ~Dr. Christine Zink
We Carry Several Functions
Located at the bottom of Rover's legs, we play an important role in bearing weight. You might find it interesting learning that dogs tend to carry the majority of their weight in their front legs.
If you're looking for more details on distributions, consider that it's estimated that about 60 percent of a dog's weight is carried by the front legs and 40 percent by the rear.
Carpal bones also allow movement and flexibility of the dog's wrist.
Did you know? Along with your dog's carpal pad, carpal bones act as sock absorbers for your dog's leg during weight bearing actions. As you can see in the picture, the carpal pad touches the ground when the dog is running and also when he's landing from a jump where it acts like a bumper.
When Things Go Wrong
While we help bear weight and absorb shock, we can only do so much. As mentioned, we are prone to injury, something that is quite common in performance dogs, such as dogs engaged in the sport of agility.
Dogs not enrolled in canine sports though can be vulnerable too, especially when running over uneven fields with rabbit holes or jumping or falling from a certain height.
Injury to us is most likely the result of some acute traumatic event or the result of chronic, repetitive strains over a certain period of time. Since we have a relatively loose fit, we're for the most part supported by ligaments that join us one to another, but these ligaments are subjected to sprains.
Sprains are simply injuries to the ligaments that connect bones.. The sprains can be of different degrees. A grade one sprain is just the ligament overstretching. A grade two sprain is a partial tear of the ligament. A grade three sprain is the complete tear of the ligament due to hyperextension of the limb or hyperflexion with rotation which causes the joint to become unstable.
This injury can cause lameness in the dog and reluctance to bear weight on the leg. In severe cases, the carpus may appear to have dropped to the ground. Left untreated, ligament injuries can cause arthritic changes to us, carpal bones. Veterinarian Christine Zink explains that in the past years she has seen several canine athletes suffering from carpal arthritis. Fractures are also a possibility.
"With so many carpal bones that don't tightly interlock with the adjacent bones, the ligaments of this joint can be easily stretched and even torn when torque (twisting) is applied to the leg. The dewclaws have the important function of reducing the torque that is applied to the front legs, especially when dogs are turning at a canter (the main gait used in agility)."~Dr. Christine ZinK
Did you know? Carpal hyperextension also occurs to a certain degree from slow degeneration of the dog's ligaments as part of the aging process. As it happens to older dogs, they becomes progressively palmigrade (walking with the palm touching the ground), explains Carpal Hyperextension
" target="_blank" rel="noopener noreferrer">Nacho Calvo, Senior Surgeon at Fitzpatrick Referrals in Surrey.
I hope this article has helped you understand us! We are small and live in the shadow, but we are quite important allowing locomotion and flexibility to your dog's legs. Take good care of us by ensuring that your dog is kept always in good shape and lean and prevent injuries by not letting your dog run on uneven surfaces.
Your dog's carpal bones
Disclaimer: this article is not meant to be used as a substitute for professional veterinary advice. If your dog is lame or you suspect your dog is showing signs of a problems with his carpal bones, consult with your vet for proper diagnosis and treatment.
- DVM360, Carpal and tarsal sports-related injuries (Proceedings) retrieved from the web on December 5th, 2016
- Dogs in Canada September 2003, With A Flick of the Wrist by Chris Zink, DVM, PhD retrieved from the web on December 5th, 2016
- Veterinary Orthopedic Sports Medicine Group, Carpal and Tarsal Injuries, retrieved from the web on December 5th, 2016