I hope that the discussion in the previous post about engineering and dog breeding gave you some insight into the reasoning and thinking of knowledgeable dog breeders
Today we are going to look at the front end assembly of the dog, and compare it to the front end suspension of a car.
Just like the front end of a car is made up of numerous parts that create a smooth, road hugging ride, the skeleton of the dog is made up of multiple bones, angles and joints. These pieces come together to allow the dog to travel at the appropriate gait for the breed, with a minimum of wear and tear on the remainder of the skeleton.
As I’m sure everyone who has owned a car for any extended period in their life knows, all of the parts of a car chassis must be properly aligned to not only prevent improper tire wear, but also to maintain a smooth ride and extend the useful life of the car.
How the slope of the shoulder affects the movement of the dog.
In these two drawings you can see that the angle of the shoulder affects how far the front is able to extend. With a steeper shoulder blade the dog is unable to extend the front leg as far. In photo A the dog is able to extend its paw beyond its nose, whereas in B the front extension is greatly reduced. The shoulder joint is a pendulum and the swing of the pendulum can only go as far as the shoulder assembly allows it to.
Here is an actual photo of a front end in motion. Following the column of the leg gives an approximation of the shoulder angle. If this dog had normal length legs the paw would be extended beyond the nose. This type of frontal reach reduces the number of steps that the dog is required to take in its lifetime and wear and tear on its body. You COULD drive your car in first gear all the time, but would that really get you where you want to go in time?
Here is the same dog standing still with approximate angles marked. Note how the line drawn from the elbow to the tip of the shoulder blade goes up through the withers to support the heaviest part of the dog – the chest.
All dogs have the same bones, in the same place and so what is the difference?
Here are some examples of poor fronts.
When all of the parts are not “assembled” correctly there are many issues that can arise out of the weaknesses in various areas.
Just like an out of alignment car front can wear the tires on the outer edges, so the long pasterns, short upper arms and steep fronts can cause dogs to not land properly on the pads of their feet. They can land on the inner or outer edge of the foot causing rotation (pronation and supination) and resultant joint issues. Among these are poor posture, stress on the outer joints, tight tendons and painful inflammation and/or arthritis.
Other deformities that can occur are Valgus Deformity, whereby the growth plates close prematurely and the ulna stops growing, while the radius continues to grow creating a twist in the pastern. As a result the dog develops a severe turnout on one or both sides. Depending on the age of the dog this can require one, or several surgeries to correct as the final surgery cannot be performed until the dog is finished growing. If the dog has not finished growing the ulna is cut to prevent the elbow joint from popping out. Once the dog is finished growing, a wedge shaped piece of bone is cut out of the radius and rotated 180 degrees to attempt to reduce the turnout. Dogs suffering from this condition suffer from arthritis, elbow and shoulder pain.
This wraps up the discussion on the front assembly as discussed from the side. A future post will tackle the subject of the dwarf front on the Cardigan and the Pembroke.
Again please feel free to forward any questions that may have come to mind. The next post will deal with the ribcage and spine. .