CONFORMATION AND SURFACE ANATOMY
The length and proportions of the neck vary with the breed; its transverse section, generally circular in smaller dogs, is somewhat compressed from side to side in larger breeds but widens toward the trunk, with which it blends smoothly.
Only a few breeds show a significant elevation at the withers. In most the back slopes slightly downward toward the tail. German Shepherd dogs show a much larger slope; these dogs walk with strongly flexed stifles and hocks. In some breeds the back is level, and in a few (including the Greyhound) it rises toward the loins after dipping over the thorax. The carriage of the tail is variable. Some conformations are characteristic of certain breeds (e.g., the tightly coiled tail of the Spitz breeds), while others express temporary mood, such as the stiffened tail that is held level or upright to denote aggressive intent and the tail depressed to cover the anus in the cringing submissive attitude. The back of a sitting dog is almost straight.Surprisingly little of the vertebral column is palpable, even in moderately lean subjects. The external occipital protuberance is a distinct landmark at the cranial end of the neck, and behind this the wings of the atlas and the spinous process of the axis are easily distinguished, confirming the position of these two vertebrae close to the dorsal surface. The remaining cervical vertebrae are more deeply placed, and it is sometimes only with dif- ficulty—if at all—that their transverse and spinous processes can be appreciated. Only the tips of the spinous processes can be palpated with certainty in the remainder of the column until the tail is reached. The dorsal parts of the scapulae and the iliac crests provide certain landmarks in the regions of the withers and hindquarters.
In cats the dorsal borders of the scapulae are very prominent and bound a hollow over the adjacent part of the vertebral column.
The hollow deepens and the scapular ridges become very pronounced when the trunk is lowered between the forelimbs in the posture cats assume when stalking. Cats also vary in the conformation of the neck, trunk, and tail. Many shorthair cats can be described as cobby, an adjective suggesting a short, thick neck and a thick, deep and fairly short trunk that is carried rather close to the ground. Cats of Oriental breeds are more slender and have a longer and narrower trunk raised from the ground on limbs that are proportionally longer, especially behind. The slinky, svelte appearance is accentuated by the longer tail and smooth flat coat. When a cat sits, its back is arched. The neutral carriage of the tail is slightly drooping, but changes from this posture are frequent and revealing to observers of cat behavior. Domestic cats, uniquely and as a behavioral trait acquired in domestication, often carry the tail upright when they are apparently content and at ease, as when greeting an attentive owner or meeting a conspecific from which they anticipate a friendly reception. The tucked-under position of the tail of the fearful cat crouching in submission and the side- to-side lashing of the cat in a pugnacious mood or merely irritated by unwanted attention will be universally familiar.