Anatomy of the Australian Cattle Dog
By H.R.Spira (B.V.Sc., M.R.C.V.S., M.A.C.V.Sc., H.D.A.)
In many respects, to talk about Cattle Dog anatomy presents an easy task; for if ever a modern breed qualifies as an example of canine anatomical normality, then surely it is the Australian Cattle Dog. Now, before too many hackles start rising, the same statement holds equally true for the balance of the so-called “Australian” Working Dogs. From point of nose to tip of tail all these breeds fall or at least should fall within the realms of correct skeletal construction and structural relationships.
Throughout the Australian Cattle Dog Breed Standard, starting with the first sentence under the heading of General Appearance, reference is made constantly to normality. This pattern is continued in the paragraph dealing with the body.
For your information, I shall quote the relevant portions:
“Sturdy, compact and symmetrically built.”
“The length of the body from the point of the breast bone, in a straight line to the buttocks, is greater than the height of the withers – as 10 is to 9.”
“The chest is deep and muscular, and moderately broad.”
Relate these three statements to a recommended height of 17 inches to 20 inches and the result is normality. Putting it another way – picture a ‘Noah’s Ark’ situation. Place an imaginary breeding pair of each one of the world’s presently recognized 300 plus breeds into a large communal enclosure. Take care of the colony in all respect but permit them to interbreed unhindered, and at will without the interference of human selection. The end result, after a few generations of such hypothetical random reproduction, in my opinion, is likely to resemble an Australian Cattle Dog in outward appearance except, perhaps, for colour – an animal not greatly at variance with the domestic dog’s ancestors, the Jackal, Dhole and Wolf. An animal designed entirely within the concept of moderation and oriented towards maximum exercise tolerance without physical exaggerations.
The Head and Neck
The skull is reasonably broad, consistent with adequate brain room coupled with superior intelligence. The cheek or malar bones as well as the zyglemtic arches are well developed, designed specifically for maximum masseter muscle development.
Animals called upon to nip, bite and, at times even fasten on to the flying limbs of moving cattle.
The foreface is relatively broad and very strong. It is of medium length, usually interpreted as equal to or slightly shorter than the distance from occiput to stop. Technically, the head shape is classified as mesaticephalic, i.e. between ultra-short or brachycephalic, e.g. Pekinese or Pug and dolicocephalic, i.e. long and lean typified by the Borzoi or Collie.
The components of both upper and lower jaws (maxillae and mandibles) are thick, dense and deep – all the better to contain a full set of 42 well developed, firmly implanted teeth.
The bite is scissors, i.e. when the mouth is closed the anterior tables of the lower incisors engage in even contact with the posterior tables of the upper incisors. The dental arches, both upper and lower, are broad. Incisorial placement is regular with the horizontal tables level. Canines, premolar and molars are large and firmly anchored – for obvious reasons.
Eyes and ears, both parts of the head, fall totally within the realms of anatomical normality. The neck region deserves brief mention. The demand is for exceptional strength. This, of course, refers only to muscular development. The seven cervical vertebrae are of average size and shape, similar in all respects to other canidae. The remarkable muscular development, necessary for work purposes, is achieved by genetic selection coupled with the correct amount of exercise.
Once more the basis is for normal function. The broad scapula are set a fair distance apart at the withers. They have to be used as the chest is called for to be capacious, with the ribs well arched (but not barrel shaped), starting at their origin from the lateral aspects of the vertebral bodies; thus correct rib cage shape in turn leads to reasonable separation of the shoulderblades at their dorsal borders.
Continuing down the sides, the official Standard mentions a “well angulated upper arm”. In anatomical terminology this translates into: “the longitudinal axis of the scapula forms an approximate 90deg. Angle with that of a humerus of equal length”. Such design equates with optimum length of stride. Naturally, the fewer the steps required to cover a given distance, the greater an animal’s endurance. And that, in a nutshell, is what the Australian Cattle Dog is all about – almost unlimited stamina.
Actual 90deg. shoulderblade/upper arm angulation is relatively rare in cattle dogs. Although such configuration usually is regarded as an anatomical ideal, when present it is almost always associated with similar stifle joint construction. Yet, in the Australian Cattle Dog Standard, the latter is called for merely to be “moderate”. Perhaps this should lead one to the interpretation that in this breed a somewhat more upright shoulder placement is acceptable. I am certain that later lecturers will raise this point.
The forearm (radius/ulna) runs vertically, viewed from both directions, from the elbow down to its articulation with the carpal joint. Its length is thus that the distance from withers to elbow roughly approximates that from the elbow to the ground.
The metacarpal bones forming the pastern are relatively short and strong. They should slope slightly away from the vertical line indicated by the forearm. The supporting ligaments, whilst firm, must be sufficiently elastic to provide the essential cushioning effect. Short, upright pasterns are as undesirable as those overlong and/or too sloping.
Correct feet are absolutely essential. The wording of the Standard is crystal clear in this paragraph. It describes the perfect canine foot, imperative to the working dog, keeping in mind the old adage that “a working dog is only as good as its feet”.
For anatomical discussion purposes this section is dealt with under two sub-headings. These are: Chest or Thorax, and Abdomen
This region is composed of 12 thoracic vertebrae above and the sternebrae below. Starting from the front these are joined together by – 8 true ribs, followed by 9-12 and, finally the last, 13th or floating rib. The nomenclature used is based on the fact that ribs 1 to 8 are attached directly and individually above and below. Ribs 9-12, whilst firmly anchored to the spinal column, are fixed ventrally first to one another by cartilage and then conjointly to the sternum. The last rib remains entirely unattached near the bottom – hence the reference to “floating”. In effect, this peculiarity of construction, means that movement in any or all directions within the anterior chest portion is severely limited; also that maximum lung ventilation occurs primarily in the area behind rib no. 8, the last securely fixed to the sternum. In front the chest ends by blending into the base of the neck. Posteriorly it is separated from its immediate neighbour, the abdomen, by a muscular sheet – the diaphragm.
The rib cage thus defined contains a number of vital organs especially the heart and lungs. It must be satisfactory in the dimensions of length, width and depth without hindering balance or movement, i.e., barrel shaped or too deep, etc., to encourage optimum development of these organs. For no breed does this statement hold truer than the Australian Cattle Dog. Lung volume and consequent ventilation plus heart room dictate air uptake and oxygenation of muscle tissue. Naturally both of these factors have direct, specific influence upon exercise tolerance.
This cavity is suspended above from the 7 lumbar vertebrae. Its walls and floor consist entirely of muscle and tendon sheets most of which originate from the lumbar vertebrae bodies. In front, the abdomen is sectioned off from the chest by the diaphragm; at the rear it joins the hindquarters.
Similar to the thorax, the abdomen houses a number of essential, sensitive organs, e.g., liver, gastro-intestinal tract, urinary and reproductive systems, spleen, etc. All require careful protection by strongly developed, tough muscles – never more so than in dogs likely to be hoofed during the course of routine daily work.
In concert with correspondingly built forequarters, anatomical normality is the order. The loins (or coupling) are asked to be well muscled in all directions – strong, yet sufficiently long to allow for an almost incredible degree of flexibility.
Rump and croup also are relatively long. This follows for correct angulation at the hip joint between pelvis and femur. As well it provides optimum space for the well-developed, inner and outer, thigh muscle insertions. The thigh muscle bodies, both upper and lower, should be of maximum dimensions, all geared to obtain the desired drive, thrust and purpose of movement.
The stifle angulation demanded by the Standard is moderate. No insistence here upon 90deg. angle between the longitudinal axis of the femur dorsally and the tibia/fibula combination ventrally as in the case of the German Shepherd. The Australian Cattle Dog Standard obviously places great emphasis upon true, supple and tireless hindquarter movement rather than upon length of stride. Whilst involved in this discussion on stifle joint angulation let’s be perfectly clear about the meaning of moderate. Dictionaries define it as “within reasonable bounds”, “avoiding excess”, etc.
Nowhere within the confines of the Breed Standard is there a hint at accepting poor or inadequate hindquarter angulation.
The hocks are called for to be “well let down”. Although clear in meaning to the majority of dog breeders and judges, this is unfortunate terminology. A far better description would be “short in rear pastern which should be positioned vertically to the ground when standing at rest”. Such anatomical conformation automatically would shorten the distance between the point of the hock and the ground.
The hindfeet, as in the case with all breeds, tend to be both somewhat smaller and narrower than those in front are. In other respects they are identical.
The final anatomical section, the tail, like all other parts in normal. It is undocked, strong at the insertion and tapers gradually towards the tip. In length, it reaches approximately to the hock joint. Carriage, important as it is to overall appearance, will be discussed elsewhere – it is not part of the discourse on anatomy.