THE NECK
The seven cervical vertebrae (Fig 1, C1 to C7) of the neck show a slight “S” curve, giving it an elegant, arched appearance. This provides a sufficiently long neck when stretched as well as the shorter, more massive muscling required for strength, the prevention of injury, and the wide base for attachment of the scapular muscles required to draw the shoulder forward. An excessively long neck is more vulnerable to injury in protection, while a short, stuffy neck makes nosework awkward and tiring. Static head carriage will be approximately at a right angle to a well laid back shoulder, or a little higher when the dog is alerted. Vertical carriage suggests a high, steep wither and topline, probably due to a low, over-angulated rear. Low carriage may be due to a roached back sloping down into a low, flattened wither. Correct head carriage gives the dog an alert, noble bearing and maximum flexibility in its work.THE WITHERS
The withers are part of the spine proper, consisting of the first nine (Fig 1, T1 to T9) of the thirteen thoracic vertebrae and supporting the first nine true ribs (Fig 1, R1 to R9). The uppermost processes of these vertebrae are greatly elongated and sloping backward, giving the withers a sloping profile, forming the highest point of the dog’s torso and anchoring the scapular muscles required to draw the shoulder backward.However, the disk portions of the vertebrae are aligned horizontally in a dog standing naturally foursquare, and only slightly sloped in a show posed dog (Fig 2). Excessively high withers are generally due, not to longer processes or a straight shoulder, but to a steeply sloping spine, again resulting from an over-angulated rear (Fig 3). Flat withers, which seem undifferentiated in profile from the rest of the back, may result from either a high set rear, or from a roaching of the spine which angles the withers downwards toward the head (Fig 4). In both cases, incorrectly oriented withers compromise the ability of the scapula to rotate freely.
THE SHOULDER
The shoulder assembly is formed by the scapula or shoulder blade, articulated with the humerus or upper arm (Fig 5). It is important to remember there is no skeletal attachment of the shoulder to the body; it rides solely in a bed of muscle. Hence a very loosely ligamented dog may tend to show good reach even with an upright shoulder, while mature dogs with good shoulders, especially males, may show less reach than they displayed in their youth. Obviously, good conditioning can help maintain good reach.
Angulation of the shoulder is important for free reach, but it is not true that the static angle of scapula to humerus must be 90 degrees. This is simply because, when the animal is in motion, its center of gravity drops, the body is lowered slightly and shoulder angulation at the supporting position closes to achieve 90 degrees (Fig 6). As well, the shoulder must carry the greater proportion of the dog’s weight, and the more vertical the supports, the less energy is consumed - try standing with your knees bent. Layback is necessary for motion, but an upright position is necessary for support. The best performing shoulder will be a compromise between the two. A 95 degree angle is more than sufficient to provide ample forward reach, impact absorption and support. Extreme extension at the trot is not especially desirable because this is an endurance gait, used to conserve energy. Maximum extension and energy consumption should be reserved for the gallop.
The scapula is slightly shorter than the upper arm and is not, unlike the scapula of the horse, capped with cartilage. Its shortness, combined with its huge area of muscular attachment, makes it an extremely powerful lever. Despite the length differential, the greatest efficiency of movement is achieved when the angle of the upper arm mirrors the angle of the scapula. A great deal of comment is made by judges on the slope of a dog’s upper arm, with no mention of the corresponding angle of the scapula, but I have never seen an animal with a short, upright upper arm who did not also have an upright shoulder blade, generally resulting in a shortened stride (Fig 7, Fig 8). The scapula can be very difficult to see or feel in a strongly muscled dog, but it normally mirrors the slope of the upper arm.
To feel the shoulder, locate the groove on either side of the breastbone of a dog standing foursquare. Immediately behind this is the point-of-shoulder, the joint between the scapula and humerus. The humerus slopes from this point to the elbow joint. The upper tip of the scapula should be directly above the elbow, at about the second or third thoracic vertebrae. With the tips of the fingers, one can palpate the spina scapulae, a sharp, deep ridge of bone that runs the length of the center of the scapula, and separates the muscles that draw the blade forwards and backwards. This spine closely follows the slope of the scapula, not the front or rear edges of the blade, which is actually quite broad. Many beginners are surprised to find the scapula is often much more upright than they predicted from simple observation, perhaps assuming it follows the black “harness line” that sometimes runs at a 45 degree angle across the coat of the shoulder.
LOWER ARM, PASTERN AND FOOT
The lower arm, or radius/ulna combination, is equal in length to the upper arm or perhaps a little longer, but never shorter (Fig 9). It is long enough to give great speed and jumping ability when necessary, and short enough to give endurance and resistance to injury. The leg should be absolutely straight, forward facing and perpendicular to the ground (Fig 10), but it also has a limited ability to rotate, increasing agility. A dog’s quality of bone and muscular condition are immediately apparent in the lower arm.
The pastern, or metacarpals, serves primarily to absorb the impact of the stride. In jumping, this impact can be considerable. It is not true that a softer pastern increases shock absorption. In fact, the softer the joint, the more easily it compresses and the less absorption is available, much like old shocks on a car. A straight pastern is capable of absorbing the most energy, but a small amount of angle, about 22 degrees, is desirable to ensure that the joint does not knuckle over on impact. I have illustrated (Fig 11), from left to right, a cat foot and upright pastern, a correct foot, two stages of breakdown of the foot and pastern, and a soft pastern in motion, showing the degree of breakdown when stress is applied. Some dogs actually drive their carpal (wrist) pads into the ground while merely trotting.
The pastern also generates its own propulsive power with each stride. At maximum compression, fully supporting the dog’s weight, the tendons running down the back of the pastern and foot are stretched, gathering energy. Short tendons stretch the most, and the straighter pastern has the shorter tendons. As the foreleg moves into the back-swing and follow-through, these tendons snap like elastics, releasing energy and generating propulsion. From the front, any tendency for the pasterns to bend or twist will warp the direction of force, wasting energy and making the leg vulnerable to injury (Fig 12).
The forefoot carries a greater proportion of the dog’s weight than does the hind foot, and is somewhat larger. Each toe is angled at nearly 90 degrees, elevating the foot over very thick, absorptive pads. The toes are held closely together, to better absorb energy and prevent injury. However, the foot is not catlike, but slightly elongated to give increased leverage, stride and speed, and the ability to spread widely in snow or water. The toes are webbed, as much as any retriever. When standing the feet should point straight ahead or only very slightly outwards. A working dog can function reasonably well with minor deviations of almost any part of its structure, but weak feet and pasterns will not withstand heavy stress over the long term, especially that tolerated by guides dogs and police dogs who must work long hours on asphalt and concrete. After temperament, sound feet are perhaps a working dog’s most essential tool.
