The Well Cat Book: The Classic Comprehensive Handbook of Cat Care - Terri McGinnis (1996)

Chapter 1. ANATOMY: GETTING TO KNOW YOUR CAT’S BODY

PHYSICAL EXAMINATION

Physical examination consists of applying knowledge of anatomy to a routine and thorough inspection of all or part of your cat’s body. Each person (including every veterinarian) develops his or her own method for giving a physical examination. The best routine to develop is one that prevents you from forgetting to examine any part and one with which you feel most comfortable.

Example: Examine your cat by systems as set out in this chapter (muscle and bone, digestive system, etc.) Then return to examine miscellaneous items such as eyes, ears, and lymph nodes. Then take the cat’s temperature.

Example: Take the cat’s temperature. Proceed with examination starting with the head and working toward the tail. In addition to examining special structures in the area—e.g., ears, eyes, mouth, and nose for the head, claws and pads for the limbs—don’t forget to examine the skin in each area and to look for the lymph nodes associated with each area. Follow up by watching your cat in motion.

Special tools needed for physical examination: A rectal thermometer is the only special tool necessary for performing a routine physical examination of your cat at home. Your other tools are your five senses, particularly the senses of touch, sight, and smell.

Special terms used in physical examination: Except for anatomical names of body parts that are mentioned and illustrated in this chapter, there are few special terms that you need to learn to help you with a physical examination. Refer to this page if any of the following words are confusing in the text.

Palpate—to examine with your hands. This is one of your most important methods of physical examination and is why you are asked to palpate or feel parts of your cat’s body so frequently throughout this book.

Terms which indicate direction in reference to the body are illustrated on the facing page.

You can do a better job of giving your cat health care at home with some basic knowledge of anatomy and physiology. Anatomy is the study of your cat’s body structure and the relationship among its parts. For example, knowing the location of your cat’s eyes and ears and their normal appearance is knowing anatomy. Physiology is the study of how the parts of your cat’s body function. Understanding how your cat’s eyes and ears function to enable your cat to see and hear are examples of understanding physiology. Although you will be able to examine and understand anatomy easily, physiology is much more difficult. Brief descriptions of how your cat’s various body parts work are given here, but it takes intensive study, such as that your veterinarian has given the subject, to really understand physiology well.

You will be most concerned with the external anatomy of your cat, but some internal anatomy is included as well, since an introduction to it will help you understand your veterinarian more easily as you discuss health problems your cat may have. The easiest and fastest way for you to become familiar with what you need to know is to get together with your cat and the following pages of this book. Handle your cat as you read the anatomical descriptions and look at the drawings. If you have a kitten, examine him or her several times during growth. You will see many changes over several months, and the physical contact will bring you emotionally closer to one another.

Looking carefully at your cat’s anatomy and encouraging your cat to sit quietly while he or she is examined are extremely important in preparing both yourself and your cat for times when you will have to give health care at home. Also, the maneuvers you go through in examining your cat at home are the same ones your veterinarian uses when giving your cat a physical examination. A cat who has become accustomed to such handling at home is usually more relaxed and cooperative at the veterinary office.

Place your cat on a smooth-surfaced table in good light for examination. The smooth surface prevents good traction and, therefore, a “quick getaway,” and the novelty (at least for some cats) of being on a table will entice many cats to stay put rather than attempt an escape. Use a gentle touch and a minimum of restraint. Most cats respond poorly to heavy restraint: A hand placed gently over or in front of the shoulders or under the chest is usually sufficient. If your cat squirms and tries to get away, interrupt the exam, lift the cat quickly off his or her feet while voicing the command “No!” firmly, then replace the cat on the table. Don’t give up. Although cats don’t seem to be as naturally inclined to respond to obedience training as dogs, they can and do learn to respond to your wishes if you make them known clearly and you are consistent. Be sure to praise your cat whenever he or she cooperates, and repeat the correction procedure wherever he or she tries to escape. The best procedure for a very uncooperative cat is to start out with very short exam periods, repeated frequently. As the cat becomes accustomed to the procedure and reassured that no injury is going to occur, cooperation improves and the examination time can be increased. There are several methods of firm restraint to use with cats, but these should be reserved for use in the veterinarian’s office or when you have to administer “disagreeable” treatment to your cat. Rely on consistent repetition and gentle handling to establish a good working relationship with your cat.

MUSCLE AND BONE

(MUSCULOSKELETAL SYSTEM)

Muscle tissue is composed of contractile units that provide the power for voluntary movement, breathing, blood circulation, digestion, glandular secretion, and excretion of body wastes, as well as many other more minor functions. There are three types of muscle tissue in your cat’s body. Smooth or unstriated muscle is involved in a host of primarily involuntary body functions such as the peristaltic (wavelike) movements of the digestive tract. Cardiac (heart) muscle, which is capable of independent rhythmic contraction, is found only in the heart, the pump for the circulatory system. Skeletal or striated muscle makes up the rest of the muscles in the body, including the diaphragm and certain trunk muscles responsible for breathing. An illustration of the muscles in your cat’s body is not included in this book because knowing their positions and names is not important in giving routine health care at home.

Bone is a continually changing and actively metabolizing tissue in the living animal. It is composed primarily of the minerals calcium and phosphorus in an organic connective tissue framework that is mainly protein. The outstanding physical functions of bone are to form the skeleton, which supports and protects the soft tissues (e.g., organs, muscles, fat) of the body, and to provide levers against which the various skeletal muscles move. The bones have other functions as well. Mineral storage is provided in the hard bone itself, and fat storage and the formation of blood cells and antibodies occur in the marrow present inside the bones.

Each cat has about 244 bones in the skeletal structure, not including tiny bones called sesamoids normally associated with certain tendons. Names of bones that might be important to you in understanding your veterinarian’s diagnosis are marked on the skeletal drawing. See whether you can locate each of them on your cat with your hands.

SKELETON

CUTAWAY VIEW OF LONG BONE

Start with the skull (head). Notice its compact, round shape and short, powerful jaws. Thick and thin layers of muscle and connective tissue overlie the bones of the skull, but these tissues are not very prominent, and you may have difficulty distinguishing between the soft tissues and bone. You may be able to feel the relatively thick, paired temporal muscles over the top of the head between the ears and the masseter muscles that lie in the area of your cat’s cheeks. These two pairs of muscles function together with smaller muscles to close the mouth. The rest of the skull feels very bony. Trace the bony area between the temporal muscles back to its end behind the ears. This small, hard bump at the end is called the occipital protuberance and is a normal part of every cat’s skull. Another bony area easy to identify is the mandible, the lower jaw. You move this bone when opening and closing your cat’s mouth.

The skull is attached to the rest of the skeleton by the cervical vertebrae. Try to feel these neck bones by moving your fingers firmly over the sides and top of the neck. You will find it very difficult to feel any bony structures because of the well-developed muscles that cover the neck. The cervical vertebrae, along with the lower vertebrae, form your cat’s spinal column (backbone).

The thoracic vertebrae start in the area between the edges of the shoulder blades. You can feel the curved upper edge of each scapula (shoulder blade) near the middle of the back at the withers. Each scapula and the muscles that cover it can be seen to move freely when your cat walks and runs. Use your index finger to feel the spines of the thoracic vertebrae between the shoulder blades. Unless your cat is pretty fat you will be able to trace these bones with your finger down the center of your cat’s back. They become the spines of the lumbar vertebrae in the area behind the last rib and disappear near the hip where several vertebrae are joined to form the sacrum. You can feel only the spines of the vertebral bones but not the rest of the bones themselves because a heavy group of muscles lies on each side of the spinal column down the back. These epaxial muscles are most prominent in the lumbar region where you can feel them easily by running your fingers along each side of the spinal column. Unless your cat is tailless, you will probably be able to feel each coccygeal (tail) vertebra under its covering muscles.

Now examine each leg starting at the foot. The average cat has five digits (toes) on each of the front feet and four each on the back feet. Cats affected with polydactyly, an inherited trait, may have from one to four extra digits on the front feet; but extra toes on the rear feet are quite rare. Feel each toe carefully. You will find that each consists of three bones (phalanges). These correspond to the bones in your fingers and toes. The first toe bone (first phalanx) and nail are covered by a fold of skin in the relaxed foot. These retractile nails allow your cat to walk quietly. To examine these, grasp the leg in the palm of your hand, place your index finger on the pad of the toe you want to examine and your thumb over the top of the same toe at the joint between the first and second phalanx, then squeeze your fingers together. When you do this you will find that the toenail and first phalanx come into view and will remain extended until you release your fingers. Move your fingers slowly up each toe to the middle of the foot. In this area each toe is attached to a long bone that corresponds to the bones that form the palm of your hand and the sole of your foot. These bones are called metacarpals in the front feet and metatarsals in the rear.

EXTENDING THE CLAW

The forepaw (front foot) attaches to the foreleg (front leg) at the carpus (wrist). Gently flex and extend this joint. If you palpate (examine with your hands) carefully, you may be able to feel the small, individual bones that form this joint. Above the carpus are the long bones of the foreleg, the radius and ulna. These bones are well covered by muscles on the lateral (outside) surfaces except in the region of the elbow, but if you feel deeply you will be able to feel bone through the muscle layers. On the medial (inside) surface you can easily feel a bone (the radius) near the wrist. Place the fingers of one hand over the elbow. Grasp the foreleg below the elbow with your other hand, and flex and extend the joint. A normal joint moves smoothly with no grating or grinding vibrations felt by your fingers. The humerus is the bone that forms the foreleg above the elbow. It is well covered with muscles that correspond to those of your upper arm. The humerus is most easy to feel at the point of the shoulder, but if you feel deeply in other areas you can also find it underlying the muscles.

Claw Mechanism

Another bone you may feel under the skin on the cat’s upper chest near the point of the shoulder is the clavicle. This tiny bone is the vestigial equivalent of the human clavicle (collarbone) that no longer serves an important anatomic purpose for cats.

In the hindlimb (rear leg) the foot attaches to the leg at the hock. This joint corresponds to your ankle. Flex and extend the joint to learn its normal movement. The fibrous band that attaches prominently on the posterior surface of the hock is the Achilles tendon. It is part of a mechanism that causes the hock to flex or extend whenever the stifle (knee joint) is flexed or extended and vice versa.

REAR LEG

The tibia and fibula are the bones that lie between the knee and the hock. Muscles cover the lateral (outside) surface of these bones, but you can feel them through the muscles and can easily feel the tibia on the inside surface of the leg in this area. The tibia helps to form the stifle joint along with the femur and patella (kneecap). Place the fingers of one hand over the patella and flex and extend the knee joint. You should be able to feel the patella move freely and smoothly as you manipulate the joint. Now move up the leg to the thigh. The femur is the long bone of the thigh. It is well covered by heavy muscles, so you will be unable to feel it easily except near the knee. Feel the muscles of the thigh and try to feel the femur under them. The femur articulates (forms a joint) with the pelvis at the hip. To test this joint, grasp the thigh with the fingers and palm of one hand and place your thumb over the area of the hip joint, then flex and extend the joint. This leaves one hand free to control your cat. You can perform this part of the examination either with your cat standing on three legs or lying on one side. Complete your examination of the musculoskeletal system by running your fingers over the sides of your cat’s chest. You should be able to feel each rib easily under a freely movable coat of skin, fat, and muscle. If you can’t easily feel the ribs, your cat is too fat. Pick a rib and follow it with your fingers down the side of the thorax (chest) to its end. If you have chosen one of the first nine ribs you will find that it attaches to a bone forming the ventral (bottom) surface of the chest. This is the sternum. The last four ribs do not attach directly to the sternum.

EXAMINATION OF THE HIP JOINT

In male cats a small bone called the os penis is present inside the penis. An equivalent structure is not present in the clitoris of the female cat.

After you have examined the major parts of your cat’s musculoskeletal system (or before, if you like), stand back and look at your cat as a whole. Are the legs straight? Are the wrist joints erect? Are there any unusual lumps or bumps? Most normal cats are very similar in conformation (bony and muscular structure) to the drawings in this book.

Now watch your cat move. All motion should be free and effortless. Do you see any signs of lameness? If you have any particular questions about your cat’s conformation or movement be sure to discuss them with your veterinarian.

SKIN (INTEGUMENTARY SYSTEM)

The integumentary system consists of the skin and its specialized modifications: the hair, the foot pads, the claws, and the anal sacs. Your cat’s skin protects his or her body against environmental changes, trauma, and germs. In the skin vitamin D is synthesized; below the skin (in the subcutaneous tissues) fat is stored. Skin is both an organ of sensation and an organ (via certain skin glands) for waste excretion. Unlike humans’ skin, however, the cat’s body skin plays only a minor role in heat regulation. Skin disease does occur in cats, and the condition of your cat’s skin and hair can sometimes tell you a great deal about his or her general state of health.

If your cat is healthy, the skin should be smooth, pliable, and free of large amounts of scales (dandruff), scabs, odorous secretions, and parasites. Normal skin coloration ranges from pale pink through shades of brown to black. Spotted skin is completely normal and may be seen in cats without spotted coats. The skin (and hair) color comes from a dark-colored pigment called melanin, which is produced and stored in special cells in the bottom layer of the epidermis (outer skin layer).

Examine your cat’s skin carefully. To do this, part the fur of longhaired cats in several places and look carefully at the skin itself. In short-haired cats run the thumb of one hand against the grain of the hair to expose the skin. Be sure to examine the skin in several places over the body, on the legs, under the neck, and on the head. When you are examining the head, note how there is a distinct thinning of hair in front of the ears. This is called preauricular alopecia; although the degree varies between cats, its presence is normal. It marks the site of the temporal glands, microscopic skin glands thought to be important in scent marking. Similar glands are present in the skin at the corners of the mouth, on the chin, and on the tail.

REAURICULAR ALOPECIA

Any buglike creatures you see attached to your cat’s skin or hair or that quickly move away as you part the hair are external parasites and should not be there. They are likely to be fleas, but may be lice, mites, or ticks. Small salt- and pepperlike, white and black granules may be flea eggs and flea feces.

A specialized area of skin of particular interest to owners of mature tomcats is the supracaudal organ (tail gland). This is an area of numerous and large oil-producing glands located on the upper surface of the tail. Although it is present in all cats, it is not particularly evident unless there is excessive accumulation of the gland’s oily secretion. If this has occurred in your cat, you will find an area of greasy, brownish secretion as you part the hair on the top of the tail. This may be accompanied by stringy, oily hairs. This unsightly condition is commonly referred to as stud tail (feline tail gland hyperplasia) and is sometimes relieved by castration and fastidious grooming.

Roll your cat on his or her side or back to see where the skin forms the nipples of the mammary glands (breasts). The mammary glands themselves are skin glands that have become modified for the production of milk. Male as well as female cats normally have four nipples on each side, although some cats have as many as five pairs. The prominence of the nipples and mammary glands in the queen (female cat) varies with age and stage of the estrous cycle. Examine your cat’s mammary glands by feeling the areas between the nipples and a wide area around them. In a normal male or anestrous female you should not be able to feel any lumps or bumps. If you find any, discuss their importance with your veterinarian.

VENTRAL ABDOMEN

If you have a young cat with short abdominal hair, you may notice a faint scarlike area on the skin at the midline near the area where the chest meets the abdomen (belly) while you are examining the breasts. This is your cat’s umbilicus (belly button). If you see a lump in this area, it may be an umbilical hernia. (See and decide whether or not you need a veterinarian’s help.)

Now return to the head to examine your cat’s nose. The skin is modified over the nose so that its superficial layers are thick and tough. This skin has no glands, but is usually moist from nasal secretions and feels cool as a result of evaporation. A cool, moist nose or a warm, dry one, however, is not an accurate gauge of your cat’s body temperature; use a thermometer. Cats’ noses vary widely in coloration. Colors anywhere from salmon or pale pink through brown to black are normal, as are spotted noses. A brightly colored nose that becomes pale or white can be a sign of illness, so be sure to become familiar with the normal appearance of your cat’s nose.

The skin is also modified to be thick and tough over the foot pads. The deepest layer of the foot pads is very fatty and acts as a cushion to absorb shock. The middle layer (dermis) contains eccrine glands, the only skin glands in the cat equivalent to humans’ heat-regulating sweat glands. If you feel your cat’s foot pads when he or she becomes excited (e.g., on a trip to the veterinarian’s office) you will find that the pads become damp with eccrine gland secretion. These glands are also responsible for the steamy footprints you may see when your cat crosses the sidewalk on a warm day.

FOREPAW

The foot pads are named according to which bones they overlie—digital, metacarpal (metatarsal in the rear feet), and carpal (none in the rear). Examine your cat’s foot pads and learn their names. Knowing the names may help you describe the location of a problem to your veterinarian.

Two unusual modifications of the skin are the anal sacs. They are located internally under the external sphincter muscles of the anus at about the four o’clock and eight o’clock positions. If you lift your cat’s tail directly upward you can see the small opening where each duct empties on each side near the opening of the anus. If the glands are full, a drop or two of brownish fluid will often drip from the openings as you lift the tail. This odorous anal sac secretion may serve to mark your cat’s stool with his or her particular identification tag. They are also often emptied explosively in stressful situations. You may be able to feel the full anal sacs by placing your thumb externally on one side of the anus and your index finger on the other side, then gently moving your fingers up and down. Full glands feel like firm, dried pea-sized objects beneath the skin. Occasionally a cat’s anal sacs don’t empty properly on their own; then you or your veterinarian must empty them.

ANAL SACS

Claws (toenails) are specialized in cats for digging, traction, hunting, and protection. To examine your cat’s claws, extend them as explained. The outer layer of the claw is horny and may be pigmented or unpigmented. The inner layer is the dermis (quick), which is highly vascular (contains many blood vessels) and is continuous with the connective tissue covering the third phalanx. Even in a dark-nailed cat you can usually see the dermis as a pink area inside the claw when it is held in front of a light. Cats normally keep their claws sharp by constant conditioning by which the old, dulled, and worn outer layers of the claws are pulled off. This normal scratching behavior sometimes becomes undesirable in cats confined indoors. Providing a cat with his or her own scratching post or nail trimming or declawing are ways to help solve the problem.

CROSS SECTION OF CLAW

Cats have three basic types of hair: guard hair, fine hair, and tactile hair. Tactile hairs (whiskers) grow out of very large sensory hair follicles on the muzzle and chin, at the sides of the face, over the eyes, and from large hair follicles located on the back of the foreleg just above the carpal pad. Their sensory function is a significant aid to your cat’s vision and hearing and is thought to be of particular importance in helping cats orient themselves in poor light. Guard hairs are the longer, coarser hairs that comprise the immediately visible outer part of your cat’s coat. Fine hairs are the soft hairs that make up the undercoat present beneath and between the guard hairs. Fine hairs consist of two types of soft hairs, awn and down or wool. Unless your cat is Cornish Rex, a special breed with a coat composed only of fine, curly hairs, whether the coat is long or short there are both guard hairs and fine hairs present. Try to distinguish between them in your cat’s coat.

Although you may notice a particular increase in the numbers of hairs your cat sheds in the spring, all cats’ coats are replacing themselves continuously. At any one time some hairs are falling out, some are in a resting phase, and others are growing in. Don’t consider shedding excessive unless you begin to see bare skin areas developing in normally haired sites. A healthy cat’s coat is neatly groomed and clean (although tomcats often look very dirty and unkempt when healthy). The coat should appear glossy and unbroken. Dark-colored coats usually seem to have more natural sheen, so take this into consideration before judging your cat’s coat. After clipping or shaving, the average cat’s coat takes three to four months to grow back fully, but it can take much longer, especially in long-haired cats.

EYES

Your cat’s eyes are similar in structure and function to your own. Light entering the eye passes through the cornea, anterior chamber, pupil, lens, and vitreous body before striking the retina. Specialized cells in the retina (the rods and cones) convert light striking them into nerve signals that pass to the brain via the optic nerve. In cats these impulses result in an image thought to be perceived in various shades of gray and perhaps some blue, green, and red, and various degrees of brightness. Although color-vision is present to some degree, it is so limited as to be insignificant in the daily life of the cat. Located behind the retina is an area of tissue called the tapetum lucidum. Its function is to reflect light that has already passed through the rods and cones back to them (increasing visual acuity in dim light). It is the structure that is responsible for the appearance of cats’ eyes “glowing in the dark.” As you examine your cat’s eyes you will see that each is surrounded by two modified skin folds, the eyelids. The edges of the lids should be smooth, even, and not rolled in (entropion) or out (ectropion). Cats do not normally have eyelashes. Look for lashes on your cat’s eyelids and if any are present, be sure that they do not turn in abnormally to rub against the eye. Between the eyelids at the medial canthus (corner of the eye near the nose) you can see the third eyelid (nictitating membrane). It may be pale pink or partially pigmented. Its normal position over the eye varies from cat to cat and has some relationship to the presence of disease. Roll back the upper or lower eyelid by placing your thumb near its edge and gently pulling upward or downward. This allows you to view the inner lining of the lids, a pale pink mucuous membrane called the conjunctiva.

EYEBALL

Normal Eyelids

Entropion

Ectropion

EXTERNAL EYE

EXAMINING THE EYE

The visible part of the eyeball consists of the cornea, bulbar conjunctiva, anterior chamber, iris, and pupil. The bulbar conjunctiva is a continuation of the lining of the eyelids that covers the surface of the eyeball except for the area of the cornea. If it contains pigment the area may look spotted or dark. In unpigmented areas the bulbar conjunctiva is transparent, allowing the eye’s white fibrous coat (sclera) and the fine blood vessels that traverse it to be seen through it. The cornea should be completely transparent. Through it you see the anterior chamber, iris, and pupil. The color of the iris varies widely among cats. Greens and yellows predominate, but many other iris colors are possible, among them orange, blue, and lavender. Sometimes cats have a different iris color for each eye. White cats with this condition (“odd eyes”) or with two blue irises are often deaf or hearing impaired (Waardenburg syndrome). The iris controls the size and shape of the pupil. Along with the eyelids, the pupil controls the amount of light allowed to enter the eye. Pupils should constrict simultaneously in bright light and dilate in dim light. When only one eye is exposed to light or darkness, the pupil of the remaining eye should constrict or dilate when the exposed one does. If your cat’s eyes are normal when you test their response to light you will find that the pupils are round when dilated, slitlike (vertically) when constricted.

Dilated Pupil

Constricted Pupil

EARS

The external part of the ear, which you can see when casually looking at your cat, is called the pinna. The pinna receives air vibrations and transmits them via the ear canal to the eardrum. The outside of the pinna is covered with haired skin like that covering the rest of your cat’s body. The inside is also partially haired, although the hair there is more sparse than that on the outside. Any visible unpigmented skin lining the inside of the pinna and ear canal should be pale pink in color. Bright pink or red is abnormal. All visible parts of the ear should be fairly clean. Normal accumulations consist of very small amounts of clear to slightly yellowish brown waxy material. Large amounts of this material, black waxy material, or sticky foul-smelling secretions are abnormal. If your cat’s ears look normal to you, or your veterinarian tells you that your cat’s ears are normal, smell them. This odor is the smell of a healthy ear. Deviations from this smell may indicate ear trouble even if you can’t see any external indication of it.

Notice on the drawing that the ear canal is vertical for a distance, then becomes horizontal before it reaches the eardrum. This makes it impossible for you or your veterinarian to see very deeply into the ear canal without a special instrument called an otoscope. An advantage of this type of ear canal structure is that it allows you to clean quite deeply into the ear canal without fear of damaging the eardrum as long as you clean vertically.

ANATOMY OF THE EAR

The structure and function of your cat’s middle and inner ear are very similar to your own. Vibrations reaching the eardrum are transmitted through the middle ear by small bones, the auditory ossicles, to the vestibular window. From the vestibular window the vibrations enter the inner ear where the cochlea converts these mechanical stimuli to nerve impulses that travel to the brain via the auditory nerve. In addition to the cochlea, the semicircular canalsand utricle occupy the inner ear. These organs are important in maintaining the cat’s sense of balance.

Hearing is present in cats when the ear canal opens at twelve to fourteen days. In general cats can distinguish among sounds better than either people or dogs. They can also hear higher pitched sounds (up to 65 kHz) than humans, whose hearing range extends to about 23 kHz.

INTERNAL ANATOMY

DIGESTIVE SYSTEM

(GASTROINTESTINAL SYSTEM)

The digestive system consists of the digestive tube (mouth, pharynx, esophagus, stomach, small and large intestines, and anus) and the associated salivary glands, liver, gallbladder, and pancreas. Few of the foodstuffs necessary for growth, life, and work enter the body in a form that can be absorbed directly by the intestines and put straight to use by the body. Therefore it is the digestive system’s function to convert foodstuffs to absorbable nutrients, using both mechanical and chemical means.

Anatomically you will be primarily concerned with the beginning and the end of the digestive tract—the mouth and the anus. The locations of the other structures are indicated on the drawing of internal anatomy. With practice you may become quite familiar with the shape and feel of some of the internal organs because most cats are small enough and have relaxed enough abdomens to make palpation easy. Feel gently and carefully; too firm or rough an examination can cause injury to your cat. With your cat standing, feel for the liver and stomach by running your fingers down the edges of the ribs bordering the abdomen. You may feel the firm, sharp edge of a normal liver most easily along the rib edge on the right side. Round liver edges or a liver that extends for some distance beyond the rib may be abnormal. When full, your cat’s stomach will be felt as a doughy or lumpy mass against the left side of the abdomen near the rib. You will also encounter the spleen on the left side. Feel your cat’s intestines by grasping the abdomen between the thumb and fingers of one hand. Reach up along each side of the abdomen, bring your thumb and fingers toward one another, then move them downward toward the umbilicus. The intestines will slip through your fingers like wet noodles. If you reach high up in the posterior (towards the tail) part of the abdomen you may be able to feel your cat’s colon full of stool. It will feel firm and somewhat sausage-shaped. If you become familiar with the shape and feel of a normal stool in your cat’s colon, it may help you in the diagnosis of diarrhea or constipation. As you perform your examination of the digestive system, you are likely to encounter the kidneys and bladder. For information about these organs turn.

MOUTH

Most cats are reluctant to have their mouths examined, especially the first time. Don’t give up if your cat objects and tries to squirm away as you start your examination. Make your intentions clear and proceed with an air of confidence. If you are hesitant in your motions most cats will be quick to take advantage of the situation. Begin the examination by lifting each upper lip individually with the cat’s jaws closed. Use one hand to steady your cat’s head, if necessary, while examining with the other. This allows you to examine the buccal (outer) surfaces of the teeth and gums.

HEALTHY GUMS

SEVERE GUM DISEASE

Healthy gums feel firm and have edges so closely applied to the teeth that they look as if they are actually attached to the teeth. Gums fill the upper part of the spaces between the teeth, forming a “V” (an inverted “V” with the lower teeth) you can see between each front tooth and its neighbors. In unpigmented areas healthy gums are pink. Very pale pink or white gums, yellowish gums, red gums, or a red line along the tooth edge of pink gums is abnormal. Many normal cats have black-spotted gums, some with so much pigment that it is difficult to find a pink area to examine.

Cats’ teeth are designed for grasping, tearing, and shredding. They are typical of an animal designed by nature to eat a carnivorous diet. In a normal mouth, the upper front teeth (incisors) just overlap the lower ones. An excessive overlap (overbite) is abnormal, as is a mouth structure in which the lower front teeth extend beyond the upper ones (underbite). A mild overbite or underbite doesn’t seem to cause functional problems. However, cats bred for short faces such as Persians may have extreme underbites which are functionally unsound and are related to health problems. Be sure to check your cat’s bite and the surface of each tooth. Abnormal tooth placement in young cats can affect jaw development and the later placement of adult teeth, so any problems you find should be immediately brought to your veterinarian’s attention. The surfaces of the teeth are white in young cats and get yellower as the cat ages. A fingernail scraped along tooth surfaces should pick up little debris. Try it. Mushy white stuff that may scrape off is called plaque, a combination of saliva, bacteria, their by-products, and food debris. This can be removed easily by “brushing” your cat’s teeth. Hard white, yellow, or brown material is tartar or calculus (mineralized plaque) and must usually be removed by your veterinarian.

Teeth are categorized into four types: incisors (I), canines or cuspids (C), premolars (P), and molars (M). Veterinarians use a formula to indicate the number and placement of each kind of tooth in the mouth. The letter indicates the kind of tooth; the numbers placed next to the letter indicate how many of that particular kind of tooth are present in the upper and lower jaw of one half of the mouth. The average kitten has twenty-six deciduous teeth (baby teeth) arranged in the following manner. Starting at the middle of the front teeth (incisors)

A kitten has no molars. Therefore the emergence of these baby teeth and their replacement by permanent ones is a convenient way to estimate the age of a young cat (see table).

The average adult cat has thirty permanent teeth:

It is not unusual to find cats with fewer teeth than this “standard” number. Many cats never develop the full number of incisor teeth, others lose their teeth relatively early in life. Others are missing premolars or molars. If the other teeth and the gums are healthy, a few missing teeth don’t seem to cause any problems. Once a cat’s permanent teeth have erupted it is more difficult to use them as a guide to age.

Now examine the inner (lingual) surfaces of the teeth, the tongue, and the posterior part of the mouth. To open your cat’s mouth, place one hand around the upper part of his or her head and push inward on the upper lips with your fingers and thumb as if you were trying to push them between the teeth. As your cat starts to open the mouth, use the index finger of your other hand to pull open the lower jaw by pushing downward on the lower incisor teeth. Look inside. You will see the rough surface of the tongue below, the hard palate above, and the inner teeth surfaces.

An unusual sense organ, the vomeronasal organ, opens into the mouth at a small bump on the hard palate just behind the upper teeth. The rest of the organ is located in the soft tissues above the palate. When cats investigate objects with their mouths held slightly open (the Flehman or gape response) they are directing scents to this organ for evaluation.

OPENING THE MOUTH

If you move quickly you can use your finger to push the tongue to one side or the other to look under it. Using the index finger of the same hand you used to open the lower jaw, press down on the tongue. As you press down, try to move the tongue slightly forward. If you do this properly, you will mimic your doctor’s use of a tongue depressor, allowing you to see the soft palate as a continuation of the hard palate, and the palantine tonsils. Cats’ tonsils reside in a pocket (the tonsilar fossa or sinus), so they aren’t easily seen unless they are enlarged. Be very careful when examining a cat’s mouth. If there is any significant resistance withdraw your hands immediately to avoid injury.

PHARYNX

TEETH AS A GUIDE TO YOUR CAT’S AGE

Rarely, deciduous teeth may be retained as the permanent ones erupt. These may have to be removed by a veterinarian if they interfere with normal adult tooth placement.

After one year of age some staining and tartar accumulations are usually present on the teeth. There is no reliable way to use teeth as a guide to age, however, after a cat is mature.

LYMPH NODES

Tonsils are a type of specialized lymphoid tissue (containing many special cells called lymphocytes) similar to your lymph nodes and to lymph nodes located in other parts of your cat’s body. You can feel some lymph nodes on your cat’s head in the area located below your cat’s ear and behind the cheek where the head attaches to the neck. They are very small, firm, smooth-surfaced lumps associated with a larger similar lump. The larger lump is one of the cat’s several salivary glands, and the only one you will be able to feel. After you feel the normal salivary gland and its associated lymph nodes and become familiar with them, try to feel the other lymph nodes indicated on the drawing. (You may need your veterinarian’s help with this; unless the nodes are enlarged they can be difficult to find the first time you try to feel them.) When you find one, learn its normal size and shape. Lymph node changes (most commonly enlargement) should alert you to have your cat examined by a veterinarian since they are often a sign of serious illness or infection.

LYMPH NODES

ANUS

The anus is the specialized terminal portion of the digestive tract through which indigestible material and waste products pass as stool. Most adult cats have one or two bowel movements daily. The number of bowel movements and the volume of stool passed, however, are dependent to a great degree on the amount of indigestible material in the diet. Cats eating dry food will tend to pass more feces than cats eating a highly digestible muscle meat, egg, and milk product diet, due to the higher fiber content of dry cat food. Normal stools are well formed and generally brown colored, although some diet ingredients may make them darker (liver) or lighter (bones). Extremely large volumes of stool, unformed, abnormally odorous stools, or unusually colored stools may indicate digestive tract disease. Be sure to try to observe your cat’s stools several times a week.

Anal sacs have been discussed with the skin. If you have not yet examined them, do it now while learning the normal appearance of your cat’s anus. You may also want to learn to take your cat’s temperature at this time since it should be a routine part of any physical examination and is usually taken rectally.

REPRODUCTIVE AND URINARY ORGANS

(GENITOURINARY SYSTEM)

MALE UROGENITAL ORGANS

Major portions of the male cat’s reproductive system are located externally within reach of your examination. Many cats resist a thorough examination of their genitals, however, so don’t feel dismayed if you can’t examine all parts as described. The testes (organs that produce sperm) are located in the scrotum (skin pouch) of the male kitten at birth or very shortly thereafter and should be relatively easy to feel by six weeks of age. Normally there are two testicles present, each of which feels firm, smooth, and relatively oval beneath its loose covering of skin. If your cat has one or no testicles in his scrotum (unilateral or bilateral cryptorchidism) the condition may need veterinary attention. If you palpate carefully, you can feel a small lump protruding off the posterior end of each testicle. This is the tail of the epididymis, which stores sperm. To examine your cat’s penis you must first retract the skin fold which covers it (the prepuce or sheath). To do this, grasp the prepuce gently but firmly between the index finger and thumb of one hand. Then push the skin fold anteriorly toward your cat’s head. As you do this you will see the pink tip of the penis start to protrude posteriorly; a cat’s penis points in the same direction as the tail. If you have gotten a successful grip the first time, the rest of the penis will protrude once the skin fold is pushed fully forward, and it will remain protruded as long as you hold the retracted skin in place. If you have difficulty retracting the sheath the first time, try getting a better grasp. Try several positions before giving up.

EXTRUDING THE PENIS

The surface of the penis is covered by a pink mucous membrane. Prominent curved, horny papillae protrude from its surface in the area of the glans (expanded end of the penis) in mature, uncastrated males (tomcats). It is thought that these rough projections may be involved in stimulating the female cat to ovulate following mating; they may also provide additional sexual stimulation to the male and act as a holdfast. If your cat is very young or castrated, you will find that the surface of the glans penis is smooth. The spines begin to develop at about six months of age and have usually disappeared by six months following castration. The urethra (tube through which urine and reproductive secretions pass) can be seen to open at the end of the penis. It is extremely narrow in all male cats. If you see your cat urinate, notice what a thin stream of urine this produces. Any secretions present on the surface of the penis should be clear, not cloudy or colored.

Sperm are produced in the seminiferous tubules of the testicles. From the testes the sperm travel to the epididymis for storage and maturation. During ejaculation sperm travel through the vas deferens into the urethra where they are mixed with secretions from the prostate gland and bulbourethral glands, which are located internally and are not accessible for routine examination.

The vulva and clitoris are the only female cat’s genitals that can be seen externally. The internal portions of the female reproductive tract—uterus, cervix, ovaries, and fallopian tubes—can be found on the illustrations here. The urethra empties into the vagina anterior to a point you can see without special instruments. You may be able to see the tiny, dark pink clitoris in its fossa by gently spreading the vulvar lips with your fingers. This also allows you to see some of thelining of the vulva and vagina. These mucous membranes should be pink in color; any secretions present are normally clear.

FEMALE REPRODUCTIVE SYSTEM

VULVA

FEMALE GENITAL ANATOMY

You can find additional information on reproduction in the chapter Breeding and Reproduction, starting.

The urinary system of both male and female cats consists of two kidneys, two ureters, the bladder, and the urethra. Look for these organs on the illustrations. Nephrons (units of specialized cells) in the kidneys filter the blood to remove toxic metabolic wastes and are also important in maintaining the body’s proper electrolyte and water balance. Urine formed in the kidneys passes through the ureters to the bladder where it is stored until it is eliminated through the urethra during urination. Normal cat urine is yellow and clear and has a distinctive odor. This odor is extremely intense in tomcats and is used to mark territory during the act of spraying. The intensity of the yellow color of urine increases as the amount of water excreted decreases and vice versa. If your cat is not fat you will probably be able to feel the bladder and kidneys. With your cat standing, provide restraint with one hand under the chest while using the other one to feel for the bladder in the posterior abdomen between the rear legs. A bladder containing urine will feel somewhat like a water-filled balloon varying anywhere from about the size of a Concord grape to the size of a large lemon. Feel gently for the kidneys by grasping the abdomen with both hands, left on the left side, right hand on the right side. Reach high into the mid-lumbar area, then bring your fingers toward one another. Each kidney should feel firm, smooth, and relatively oval in shape. Most normal adult cat’s kidneys are about the size of a small apricot, but there is much individual variation with body size and with the amount of body fat, since a layer of fat normally covers the kidneys. You may find the right kidney somewhat more anterior than the left one, but both move rather freely and will not be found in exactly the same position in each examination.

RESPIRATORY SYSTEM

The cat’s respiratory system consists of two lungs, the air passages leading to them (nasal cavity, mouth, pharynx, larynx, trachea, bronchi), the diaphragm, and the muscles of the thorax. The system’s main function, as in humans, is to supply oxygen to the body and to remove excess carbon dioxide produced by metabolism. In conjunction with the tongue and the mucous membranes of the mouth, the respiratory system has a secondary but extremely important function of heat regulation, since the cat has no highly developed mechanism for sweating. Unlike dogs, however, cats rely on panting for cooling only under extreme heat stress. The nostrils and nasal passages are also important to the cat’s highly developed sense of smell.

The only parts of your cat’s respiratory system you can see are the mouth and nostrils. Special instruments are needed to look into the nasal cavity; and this is difficult, even with special instruments, because the passages are so small. Look at your cat’s nostrils. Any secretions from them should be clear and watery; sticky, cloudy, bloody, yellowish or greenish nasal discharge is abnormal.

You can feel your cat’s larynx (Adam’s apple) by grasping the neck on the undersurface where it meets the head. The larynx feels like a small, hard, fairly inflexible mass of tissue. It helps control the flow of air through the trachea and lungs and is the location of the vocal cords responsible for your cat’s meow. The purr also originates in the larynx. When certain muscles within it contract narrowing its opening (the glottis), the air turbulence created during breathing results in the purring sound.

Notice the character of your cat’s respirations at rest and after exercise. A normal cat at rest breathes about twenty to thirty times per minute. The movements of the chest are smooth and unstrained. After exercise, of course, the rate is much faster, and on very hot days or during periods of extreme excitement the rate increases above normal and panting may occur. Changes in the rate and character of a cat’s respiration may indicate disease. Be sure to become familiar with your cat’s normal breathing at rest, on cool and warm days, and during and after exercise so you can tell when changes have occurred.

HEART AND BLOOD

(CIRCULATORY SYSTEM)

Your cat’s circulatory system is similar to your own. It consists of a four-chambered heart that serves as a blood pump, arteries that carry blood away from the heart to the capillaries where molecular exchange occurs, and veins that return blood to the heart. There are no direct methods you can use to examine this system. A stethoscope (available at medical supply houses) will aid you in listening to your cat’s heart, but one is not necessary to deal with everyday health problems you may encounter. The normal heart beats about 130 times per minute in the resting cat. Slightly agitated or nervous but normal cats often have heart rates between 165 to 200 beats per minute. You can feel the heartbeat by placing your fingers or the palm of your hand against your cat’s chest just behind the point of the elbow. Placing your hand completely around the lower part of the chest with your fingers on one side and your thumb on the other is another simple and easy way to feel your cat’s heart beat. If you cannot feel the heartbeat, you can usually hear it by placing your ear (or a stethoscope) against the chest. Each heartbeat consists of a strong, low-pitched thud, followed by a less intense, higher pitched thud, followed by a pause—lub-dup… lub-dup … lub-dup. In most healthy cats this rhythm is very regular, unlike dogs who usually have a variable heartbeat rhythm.

SCHEMATIC DRAWING OF HEART

FEELING THE HEARTBEAT

To take your cat’s pulse, place your fingers at the middle of the inside surface of the rear leg near the point where the leg meets the body. This is the area where the femoral artery passes near the skin, allowing you to feel the pulse. The heart rate and pulse rate should be the same; true discrepancies between them indicate serious circulatory problems. It is easiest to count the heart rate or pulse for fifteen seconds, then multiply by four to calculate the rate per minute.

FEELING THE PULSE

A measure of capillary circulation is capillary refilling time. To measure this, press one finger firmly against your cat’s gums. When you lift it away you will see a pale area that should refill with blood almost instantaneously. This measure of circulatory effectiveness can be helpful in evaluating possible shock.

Blood is the fluid transported by the circulatory system. Blood consists of plasma, platelets, red blood cells, and white blood cells. The composition of the liquid portion of the blood, plasma, is very complex. It carries nutrients throughout the body, removes wastes, including carbon dioxide, and provides a means of transport for the hormones produced by the endocrine glands, as well as transporting the particulate blood constituents, the platelets and the red and white blood cells. Platelets are produced primarily in the bone marrow of the adult cat. These small bodies help prevent hemorrhage when a blood vessel is injured by aggregating together to form a physical barrier to blood flow and by stimulating clot formation. Red blood cells carry oxygen to the tissues and to a much lesser degree transport carbon dioxide away. They give blood its red color. They also determine the cat’s blood group (type). Cats have three blood types A, B, and AB. Cats in group B have the greatest risk of reaction to unmatched blood transfusions since blood type A is most common. Ideally the blood type of both the donor and recipient should be known prior to blood transfusion. A veterinarian can have your cat’s blood typed in anticipation of an emergency requiring blood transfusion or donation. There are several kinds of white blood cells, and each type has a particular function. As a group the white blood cells are most important in preventing and fighting infection. The red blood cells and white blood cells often change in number and in type when a cat becomes sick. The measurement of these cells by means of a complete blood count (CBC) performed by your veterinarian is frequently necessary for correct diagnosis and treatment of cat health problems.

The spleen is an abdominal organ that, although not necessary for life, has many functions related to the blood. You may have felt this organ during your examination of the digestive system. In the adult cat the spleen produces some white cells, and, in times of need, it can produce red cells as well. It is a blood reservoir that can supply large numbers of red cells rapidly when the body needs oxygen. The spleen also removes old and abnormal red blood cells from circulation and stores some red cell components, such as iron.

LYMPHATIC AND IMMUNE SYSTEMS

The lymphatic system consists of lymph nodes and a network of thin-walled, permeable lymph channels and collecting ducts distributed throughout the body and associated with localized lymph nodes. The lymph nodes filter the tissue fluids (which constantly bathe all body cells), removing foreign particulate matter and returning the fluids and blood cells they may contain to the general circulation via lymphatic channels that eventually empty into the great veins associated with the heart. Through its immune functions the lymphatic system also provides a way for the body to detect, identify, and destroy foreign material that invades it.

Simply put, the immune system processes foreign materials such as viruses, bacteria, other microbes, and environmental proteins through specialized white blood cells. Neutrophils, produced in the bone marrow and normally suspended in blood, can migrate quickly to the site of an infection to destroy and engulf some foreign materials and microbes. Macrophages can engulf invaders not destroyed by neutrophils and can signal other cells in the immune system to respond. Two types of lymphocytes, T cells and B cells, play central roles in the immune process. These cells are distributed throughout the body but are found aggregated in the lymph nodes, bone marrow, and spleen.

T cells arise in the fetal bone marrow and must be processed in the thymus gland to become functional. They play a major role in the body’s ability to recognize itself and are, therefore, important in eliminating cancer cells and infectious agents. They also play a major role in graft rejection and in certain allergic responses. T cells elaborate complex protein substances that act on other cells in the immune process in a wide range of biological activities.

B cells mature in the bone marrow, which serves as a continuing source of this kind of lymphocyte throughout life. B cells are activated to produce proteins called antibodies that are very specific for the antigens (proteins identified as foreign) that provoke them. B cells can produce their antibodies only with the aid of specific T cells (called helper T cells) acting together with specific stimulated macrophages that present the antigen to both the T and B lymphocytes. As time passes, the immunostimulated B lymphocytes differentiate into plasma cells, which are short-lived but capable of producing large quantities of antibodies, and long-lived memory B cells. These memory cells retain the ability to respond rapidly with antibody production specific for the same invader should reexposure occur.

Although you cannot detect most parts of the immune system during your physical exam, its normal daily functioning is vital to your cat’s health. For information on how the immune system affects preventive vaccination of your pet.

NERVOUS AND ENDOCRINE SYSTEMS

Integrating the functions of the various parts of the body is the main function of the nervous system and of the endocrine system. You cannot normally see or feel any of the components of these systems when you examine your cat. Nonetheless, if one system or the other is functioning abnormally it is usually not long before some striking change will occur in your animal. In general, the nervous system (brain, spinal cord, and peripheral nerves) is responsible for rapid body adjustments to environmental and internal stimuli. The endocrine system, for the most part, is responsible for more gradual responses that are mediated by chemical substances secreted by endocrine glands into the bloodstream (hormones). Complete neurological and endocrine examinations are not a routine part of your or your veterinarian’s physical exams. For your information a brief outline of the functions of the various endocrine glands is listed. Look at the drawings of the internal anatomy to see where these various glands are located. For very detailed information about these glands and other parts of your cat’s anatomy and physiology you may want to consult the following books:

Cunningham, James G., Textbook of Veterinary Physiology, W.B. Saunders Company, Philadelphia, Penn., 1991.

Gilbert, Stephen G., Pictorial Anatomy of the Cat, University of Washington Press, Seattle, Wash., 1968.

McClure, Robert C., Mark J. Dallman, and Phillip G. Garrett, Cat Anatomy, Lea and Bebiger, Philadelphia, Penn., 1973.

Swenson, Melvin J., ed., Dukes’ Physiology of Domestic Animals, Cornell University Press, Ithaca, N. Y., 10th ed., 1984.

Don’t be surprised if your first examination of your cat takes an hour or two. If you have a kitten or an adult cat who has not been handled frequently before, it may take a full day to complete the exam because you may have to divide it into several parts separated by rest periods to compensate for your cat’s reluctance to hold still for examination. Repeat your physical examination at least once a week while you are learning what is normal for your cat. By doing this you will train your cat to cooperate, and you will soon find that you no longer need to refer to this book so often. The time it takes for you to perform the examination will shorten considerably as you practice. You should eventually be able to finish it in about fifteen minutes. Most veterinarians become so skilled at physical examination that, until you become aware of what they are doing, you may not even realize that a physical examination is being performed. Your veterinarian may easily perform a routine physical in five or ten minutes. Special examinations, of course, take much longer.

Once you are familiar with your cat’s anatomy, how frequently you repeat certain parts of a physical examination varies. You can get a good idea of your cat’s general health by just being aware of his or her appetite and activity level. Be sure to examine the ears, eyes, teeth, and skin at least every two weeks. And examine the mammary glands of females, in particular, monthly. If your cat spends a considerable portion of time outside, you will probably have to make more of a conscious effort to do the examinations. Be sure to set aside several times a week to study your cat’s condition; most illnesses are best treated if discovered early.