DOG BLOG
Musings
Stern Warning!
The stern or tail is not inconsequential. If that were the case, Mother Nature certainly made an engineering error in nearly every warm blooded mammal and in most of her cold blooded, footed creatures. From the lowest lizard to the otters, nearly all have tails.
The stern or tail is not inconsequential. If that were the case, Mother Nature certainly made an engineering error in nearly every warm-blooded mammal and in most of her cold-blooded, footed creatures. From the lowest lizard to the otters, nearly all have tails.
It is human nature to meddle or interfere with the natural order illustrated by the number of various dog breeds. Today’s AKC recognized breeds have approximately 47 tail types which is predictable because humans have a habit of making things complicated. The ultimate irony though is that our forebears already modified Mother Nature’s work and put pen to paper to dictate the breeds’ ideal physical traits and characteristics, yet we frequently see today’s fanciers ignoring these demands. In many cases, today’s breeders are changing the rules again with a casual disregard for the tail, as if the stern had no purpose. If that were the case, then why did nature initially design it?
In nature, the stern serves a myriad of purposes and our dogs are not exempted. Tails communicate, provide equilibrium and stability, and even serve as tools. For example, suitable for their place of origin, a number of our Northern Spitz breeds use the tail to protect and warm their face when curled in a ball. The tail on whippets or greyhounds is used as a counter balance at high speeds in tight turns, as both breeds natural quarry was hare which does not flee in straight lines. Further, the stern is highly valued in our scenthounds for locating in the brush but also communicates or is a beacon to the Master of Hounds. Apart from the designated versatile hunters, gun dogs’ tails such as the retriever class, is not docked and is often used as a rudder in rough waters. Breeds vital to fishermen, such as the Flat-Coated Retriever or Chesapeake Bay Retriever, have tails that are important appendages. The Chesapeake tail has a necessary, strong insertion or set-on. It should be fairly heavy at this base as he worked in icy, rough ocean waters launching himself off boats, which requires a strong, powerful stern. A dog without such or even docked may not fare well. Hence, one of the reasons why it is unacceptable for a Chesapeake to have a curled tail. Contemplate the Newfoundland’s function as a utilitarian dog, but excels in water and must have a broad and strong tail insertion with no kinks in the vertebrae.
Moving beyond tail function is the form of tails, that which is frequently modified or overlooked by neophytes and breeders. The tail is the final portion of the spine and is composed of coccygeal vertebrae, in which the tail root attaches to the sacral region of the croup. This set-on varies with breed blueprints. A dog whose tail is low-set is typical of a gently rounded croup such as the Bearded Collie. Conversely, an Australian Terrier’s tail is set on high and whose sacral vertebrae, or croup is seemingly a firm, level line from the withers to the set-on.
We see dogs who are supposed to have a low tail set, yet have an unattractive, gay tail. This is not an insignificant adaptation to a breed blueprint and the fault lies in the slope of the pelvic girdle. Imagine using a negative angle (an angle that goes clockwise) to measure the slope of the iliac wing and ischial tuberosity, which the amount of turn on the angle is too slight. It may measure a negative 15 degrees instead of a desired 30 degrees. As such the tail root is too high, inducing tail carriage above the horizontal line of the back and is not only unattractive but is an engineering defect. A common cause is a faulty, shorter pelvis, along with the flatter pelvic slope creating a ‘chopped off behind’ appearance. The latter being the ischial tuberosity and upper thigh muscles do not extend beyond the set-on of the tail, the dog lacks a ‘shelf.’ This all has consequences in gait and power.
I will continue the discussion and merits of the tail to the hindquarters in an upcoming segment. For now, hopefully, you understand and appreciate the tail’s importance as breeders should pay heed to this stern warning.
This article first appeared on the Canine Chronicle website. Short URL: http://caninechronicle.com/?p=36592
Posterior Judgement
Fanciers and Judges make a great to-do over the dog’s hindquarters but can they really recognize a sound, strong pelvic girdle and pelvic limb construction? Although breed blueprints revolve around specialization demanding differing angles to include descriptive terms, such as sweep of stifle or great length from hip to hock, unimpaired hindquarters construction is the same, no matter the breed. First,...
Fanciers and Judges make a great to-do over the dog’s hindquarters but can they recognize a sound, strong pelvic girdle, and pelvic limb construction? Although breed blueprints revolve around specialization demanding differing angles to include descriptive terms, such as sweep of stifle or great length from hip to hock, unimpaired hindquarters construction is the same, no matter the breed.
First, we start with the basic technicalities to differentiate the thoracic from the pelvic limbs. The pelvic limbs are fused and joined to the vertebral column, whereas the thoracic limbs are connected by muscle and ligaments, that is to say not bone to bone. The pelvic limbs are heavily muscled, longer and more angular than the thoracic limbs as they are responsible for propulsion. Pelvic limb movements surge or throw body weight forward, and the thoracic limbs catch and support this weight no matter what the stride and gait. Please note that stride and gait are not the same but more on this in another essay. One more fundamental is that the arrangement of the pelvis girdle and rump muscles enables the simultaneous extension of the hip, stifle, and hock. I will delve into regional musculature in another series.
Moving on, the strength of the pelvic girdle and limbs, length, and angularity of its bones and quality of muscling, in almost all cases, ultimately determines successful running speed. Because the dog species are carnivores, Mother Nature constructed him for running. Unmistakably, humans have intervened in evolution creating significant variations in the species and their functions. Some breeds have substantially limited running abilities, i.e., today’s Bulldog, Pekingese. Despite this, even the Bulldog’s hind end should be strong and muscular.
Many fanciers have taken a great liberty, far too much, redesigning the hindlimbs. Frequently we see improperly angled croups, plus over and under angulated hindquarters. Evaluating ‘hindquarter angulation’ involves two methods, yet often fanciers confuse the two or sometimes do not consider the other. The first is determining the angle of the pelvis from the horizontal called the pelvic slope. To determine pelvic slope we estimate a straight line from the forward part or crest of the ilium, to and through the ischial tuberosity. This line intersects with the horizon, therefore, creating a determinable angle. The most significant point is that this slope of the pelvic girdle can directly affect the progression and ability of the hindquarters forward-drive and thrust, otherwise known as propulsion. A steeply angled pelvis usually will restrict back reach locomotion.
The second process of determining hindquarter angulation is estimating the stifle joint angle. This angle is created and defined by two lines of intersection. One line is running centerline through the femur that is articulating from the hip bone to the stifle (knee joint), and the other line runs centerline through the tibia bone which articulates with and is connected to both the stifle and the tarsal joint (hock). Notably, the tibia is one of the major weight-bearing bones in the hindquarters. This method is standard in ascertaining symmetry between the forequarter and hindquarter angulation establishing if a dog is balanced.
The average, desirable stifle joint angulation for functioning dogs is 90-110 degrees. Simplifying the term ‘overangulated’ is when the angles of the femur and or the tibia themselves are set too sloping. An angle created by the femur through the axis of the tibia that is narrow, or more closed, is less than 90 degrees and is over angulated. In contrast, open angles might be more than 110 degrees where such a straightened femur and tibia do not generate rear power and drive. Invariably, in numerous breeds we see an unequal length of bones in the hindlimbs where the tibia bone is both too long and steeply sloped. This faulty engineering and redesign draws out the distal (lower) tibia, tarsal joint and rear feet, placing them dramatically behind the ‘seat bones,’ thus, greatly weakening the rear assembly’s capacity, thrust, and strength.
I repeatedly emphasize that the angle of the pelvis is very influential. Since the pelvic angle affects the width of the stifle and first thigh, a faulty slope limits the area for muscle attachment, and the dog has narrow thigh muscles. This is because many important muscles and tendons originate, are housed and attached on the femur, one of the strongest and longest bones in the rear. Also, consider the width of the second thigh and the lack of resulting in the phrase, weak second thighs. Second thighs are located below the knee joint and should be broad on almost all dogs. Weak and narrow thigh muscles do not show promise of speed or power.
If the dog has a weak or poorly constructed posterior, the dog is handicapped. Many breeders are careless, often planning matings based on conformation show wins without much thought to the pesky details of anatomy. Some casually believe that trends, such as over angulated hindquarters, results in accumulating more ‘wins’ then so be it, if that is what they have to do to win. In these cases, I reasonably question their posterior judgment.
Here, I have included photos depicting ideal canine hindquarters for an Irish Wolfhound. This bitch's hindquarters exemplifies strength, power, all in moderation at different ages. Neither over or under angulated, her pelvic angle along with her 30-degree croup angle regulating her tail set, are all ideal. For larger images, please click on the photo to enlarge in a lightbox. I included the 'going-away' photo illustrating exemplary rear hindquarter construction with sound, strong hocks. In this photo, the student or fancier can draw an imaginary line beginning at the center of the communal pads of the feet, up through the metatarsus and its hock joint, towards the hip socket and further, up through the crest of the ilium or hip bone. Another is of Jane's perfect, yes perfect, side gait. Rarely seen in Irish Wolfhounds, Jane's side gait was flawless, notice her rear feet comportment drive as she glides effortlessly.
This article in a previous version first appeared on the Canine Chronicle website.
Short URL: http://caninechronicle.com/?p=38978