Cat Anatomy

The cat has evolved to be a powerful, efficient predator. Its body is built for strength, speed and agility. Its senses are sharp and powerful.

Head and Teeth

Cats have short, round heads in comparison to other carnivores, like dogs. The shape of the head means that bite force is increased when a cat is attacking prey.

A domestic cat’s small body and round, short head makes it resemble a human baby. This can make humans instinctively want to care for and protect the cat.  These “cute” features could have encouraged the domestication of wildcats.

Because cats have shorter heads than other carnivores, they have space for fewer teeth.

A cat’s jaws are hinged so they can only move up and down; the jaws cannot be ground from side to side.

There are large, flattened canine teeth at the corner of a cat’s mouth. These are used to catch and kill prey.

Like all members of the order Carnivora, cats have specialized long teeth known as carnassials, which are used to tear flesh. The carnassials are formed from the first lower molar and the fourth upper premolar teeth.

Cats have small incisors - the teeth at the front of the mouth.  The cat uses its incisors to hold onto its prey.  After it has killed its prey, the cat uses its incisors to tear off fur and feathers and to tear off small strips of meat that stick to bones.

Legs, Paws and Claws

Cats have long, muscular legs. Longer legs mean that the cat has a longer stride. Because it uses fewer strides to cover a distance, the cat saves energy.  A cat walks on its toes, in a posture that is known as digitigrade. This posture lengthens the stride even further.

The first toes on the front paws, which are known as dew claws, are on the sides of the legs. They have no contact with the ground at all.

These toes have disappeared from the back paws, which have only four toes each.

Cats will use their dew claws to help them hold on to objects, including prey.

A cat has soft toe pads that distribute its weight over the balls of its feet, enabling the cat to walk in a fluid motion.

The bones in the lower hind legs are joined together by fibrous tissues, making the legs more stable but decreasing flexibility.

A cat can rotate its front limbs. This ability allows it to pick up small objects or small creatures using both front paws, to bat at things, and to use its claws as effective weapons.

Cats are the only members of the order Carnivora that use their front paws to hold prey before they perform the killing bite.

A cat uses its sharp, curved claws to help it hold its prey. It will use its claws to defend itself.

Cats can use their claws to help them climb trees. They use their dew claws, as well as the claws that reach the ground, for climbing.

A cat’s claws are retracted when they are not needed. This allows the cat to walk and run silently.

Spine

Cats have flexible spines.  They can turn their bodies when they are falling so they can land on their feet.

A cat can extend and flex its spine in order to increase the length of its stride.

Eyes

Vision is probably a cat’s most important sense. A cat is estimated to be almost six times as sensitive to light as a human.

A cat has eyes that are very large in relation to its body size - another factor that contributes to its “cuteness”.  Large eyes allow more light to enter the eye.  The eye of a domestic cat is almost as large as that of a human.

The cornea has a sharp curve, so the lens of the eye is closer to the retina. This ensures that light does not become diffused before it reaches the retina.

Cats hunt during the day and at night, so their eyes must be able to function in many different light conditions.

Like other animals, the cat contracts and dilates its pupils in order to regulate the amount of light that enters the eye. A cat can adjust the size of its pupils to account for a wide difference in the amount of light available.  In bright light, the pupils shrink to a small vertical slit or to the size of a pinprick, while the pupils dilate to a large oval or circle in dim light.

A cat has a reflective structure behind its retina known as a tapetum lucidum.  When light reaches the tapetum lucidum, it bounces back to the retina so that the cells in the retina get a second chance to respond to them. This action is what causes a cat’s eyes to glow when a light shines on them in the dark.

Of the two types of light-sensitive cells in mammalian retinas - rods and cones - cats have mostly rods.

Rods do not detect color. They are used when light levels are low. Animals that are good at gathering light have many rods.

Cones are used for color vision.

There is a patch that is full of cones in the center of a cat’s retina. This means that cats can see some color when there is enough light. Experiments have revealed that cats can see blue and green and may be able to see red. Cats probably do not see as many colors as people do and the colors they do see are probably not as bright.

A cat has to be trained to distinguish colors. This implies that cats do not use their color vision in their everyday lives.

Cats have very good depth perception. Their stereoscopic vision is more highly developed than that of all of the other animals in the order Carnivora. A cat can easily judge distances so that they can or leap up to or down from high places and pounce on prey.   To help with depth perception, a cat’s eyes are far forward and high on its skull.

A cat has a very wide field of peripheral vision. When a cat is resting, it doesn’t focus on one spot; it uses its peripheral vision to scan the environment while it seems to stare into space.  This can make the cat appear to be aloof.

Ears

Cats have very sensitive hearing. Their hearing is very important when hunting.

Cats can hear sounds that are so high-pitched that human beings can’t hear them.   A human can hear sounds up to about 15 to 20 kHz. Cats can hear sounds as high as 65 to 70 kHz.  This ability allows cats to hunt rodents, which can make sounds that are between 20 and 50 kHz in frequency.

A cat has large ear flaps (pinnae), which help it to hear low frequency sounds, such as the sound of a mouse running through grass.

All mammals have bony projections around their middle ears known as auditory bullae. In cats, each auditory bulla is divided into two cavities that are filled with air.  This arrangement helps the cat to distinguish between different low pitched sounds.

A cat can move its outer ears to locate the source of a sound and amplify it.

Nose

Because cats have short heads and shortened muzzles, they cannot depend on their sense of smell as much as other carnivores, such as dogs, do.

A cat uses its sense of smell primarily for communication.  It relies mostly on its senses of vision and hearing for hunting.

A cat has a very good sense of smell in comparison with a human.

Cats produce scents from their anal sacs and from glands on their faces, underneath their tails and between their toes.

They use these scents, as well as smells from their urine and feces, to mark their territories and to communicate information about their identities and how sexually receptive they are.

All members of the order Carnivora, including cats, have a structure at the roof of the mouth, just behind the incisors, that is known as the vomeronasal organ, or Jacobson’s organ. This structure is lined with receptor sells. A cat will transfer a scent to its vomeronasal organ by opening its mouth, curling its lips up, and wrinkling its nose. This gesture is known as flehmening. Cats tend to perform this gesture when they smell urine, so it is believed that it flehmening is used mostly to determine other cats’ degree of sexual receptivity.

Tongue

A cat’s tongue is covered with papillae - sharp projections that make the tongue’s surface feel very rough. The cat uses its papillae to groom itself and to lick particles of meat off bones.

Because cats are obligate carnivores, they do not digest sugars well, and they are not very good at detecting sweet smells.

Whiskers

A cat has whiskers on each side of its nose, around its eye, beneath its chin and on its wrists.

Whiskers, also known as vibrissae, help cats to detect things using touch.

A cat’s whiskers lie deeper in the skin than its other body hairs. The whiskers lie inside small sacs of fluid under the skin. These sacs are lined with nerve endings. When something touches the end of the whiskers, these nerve endings are stimulated.

A cat can use its whiskers to detect tiny changes in the air currents that move around objects.

It  cat will move its whiskers forward when it is about to pounce on its prey and after it has caught its prey, in order to make sure the prey cannot wriggle free and to help it find where to give the killing bite.

Cats use their whiskers to help them avoid obstacles in the dark. When there is very dim light, a cat’s pupils will dilate to let in more light. When a cat’s pupils are fully dilated, it is difficult for the cat to focus on nearby objects.

A cat that has lost its whiskers will tend to bump into things in the dark.