The Design Of The Cat (The Essential Cat)

Cats, lie humans, dogs, and giant pandas, are mammals and possess anatomical features common to mammals such as hair and mammary glands that produce milk for their young. The basic body pattern of mammals is the same, and so cats have tissues and organs that ate fundamentally no different in structure or function from those of human beings. However, just as humans are upright, omnivorous primates with unique specializations, so the body of the cat displays structural adaptations that suit its role as a quadruped, and a carnivorous predator.

The adult cat weights between two and five kilograms (six to twelve pounds). The heaviest cat on record was a thirteen-year-old female tabby from Cumbria in Great Britain that topped eighteen kilograms (forty pounds). The smallest of the wild cats, the Rusty-spotted cat of India and Srilanka, rarely exceeds one-and-a-half kilograms (three pounds) in weight.


The cat has a most elastic body. The backbone or spine is held together by muscles (rather than by ligaments as is the case in man), and this makes the back very flexible. The cat’s shoulder-joint design permits the foreleg to be turned in almost any direction. In fact, looked at in automobile terms, the “suspension” of the feline model gives a near perfect “ride”.

Another factor that enhances flexibility in the cat is that it has up to twenty-six more vertrebrae than the human backbone. Also, unlike the human being, the cat lacks a clavicle or collarbone, having instead just a small scrap of clavicle tissue deep in the breast muscle. A full collarbone would broaden the chest and both reduce the cat’s ability to squeeze through restricted spaces and limit the length of its stride. In humans, the collarbone enables the fore-arm to be lifted outward. As this movement is not required by the cat, it is unnecessary for it to have this extra bone.

The Brain

As you would imagine, the parts of the cat’s brain associated with the sense are well developed, as befits a skilled hunter that depends upon its detection mechanisms. On the other hand, the “intelligence” areas in the frontal lobes are much simpler than in primates such as the ape or human or other highly intelligent animals like the dolphin.

The Intestines

The cat is a more highly specialized carnivore than the dog and it possesses an alimentary tract designed purely for meat eating. Consequently, the cat’s intestines are proportionately shorter than those of the omnivorous human or dog. Interestingly, the intestines of domestic cats are somewhat longer than those of wild cats – probably because our pets have become used to, and fond of, more varied and to some extent less meaty food.

The Teeth And Skull

The cat has twenty-four milk teeth and thirty permanent teeth, sixteen in the upper jaw, and fourteen in the lower. These include canine, or fang, teeth for biting, and specialized blade-like carnassial molar teeth for shearing flesh. The canines in the wild animal are the main killing instrument. To give strength to the feline bite, the cat has short, sturdy jaws worked by powerful muscles that are anchored on reinforced arches of bone placed strategically on the skull.

The skull is notable also for its well-developed bone structures, which include large auditory bullae (echo chambers). These contribute to the cat’s sensitivity in hearing such delicate sounds as the scurrying of a mouse or the rustling of a bird among the leaves.

Body Shapes

Although domestic dogs come in all shapes and sizes, domestic cats have not yet been produced with much in the way of anatomical extremes. There are three main body shapes: the cobby, the muscular and the lithe. The cobby cat is a solidly built individual with short, thick legs, broad shoulders, and rump, and a short, rounded head with a flattish face. The muscular body type has medium-length legs, with shoulders and rump that are neither wide nor narrow, and a medium-length, slightly rounded head. The lithe cat is lightly built with long, elegant, slim legs, narrow shoulders and rump, and a long, narrow, wedge-shaped head.