People have associated with cats for thousands of years. Cats were first domesticated in Egypt between 1600 and 1500 bc. Even earlier, they were worshiped as gods: the Egyptian gods of fertility and war were given feline personalities. Feline images can also be found on early Greek and Roman vases, statues, and coins.
Cats do not require the same level of attention or activity often demanded by dogs. This makes them excellent pets for people who have decreased mobility, a busy lifestyle, or limited living space (such as apartment dwellers). However, as with dogs, you should consider temperament, breed characteristics, age, and other factors when deciding whether cat ownership is right for you.
Routine health care refers to the non-emergency, general care that is needed to keep your cat healthy throughout its life. This includes routine veterinary care for vaccinations, parasite control, and dental care; proper nutrition; grooming; and protection from household hazards.
Behavioral medicine is the scientific study of everything animals do, whether the animals are insects, birds, mammals, fish, or people. The field of animal behavior is concerned with understanding the causes, functions, development, and evolution of behavior. Behavior refers to the actions or reactions of an organism. Behavior is usually in relation to the environment, and is controlled by the endocrine and nervous systems. The complexity of animal behavior is related to the complexity of its nervous system. Generally, animals with complex nervous systems have a greater capacity to learn new responses and thus adjust their behavior.
Blood cells form and develop mostly in the bone marrow, that is, the tissue located in the cavities of bones. Blood performs a variety of important functions as it circulates throughout the body. It delivers oxygen and vital nutrients (such as vitamins, minerals, fats, and sugars) to the tissues. It carries carbon dioxide to the lungs to be exhaled and waste products to the kidneys to be eliminated from the body. It transports hormones, which are chemical messengers, to various parts of the body, allowing those parts to communicate with each other. Blood also includes cells that fight infection and platelets that control bleeding.
The musculoskeletal system includes the bones, cartilage, muscles, ligaments, joints, tendons, and other connective tissue. It supports the body, permits movement, and protects the vital organs. Because many other body systems (including the nervous system, blood vessels, and skin) are interrelated, disorders of one of these systems may also affect the musculoskeletal system.
The nervous system is made up of the brain, spinal cord, and several different kinds of nerves that are found throughout the body. These create complex circuits through which animals experience and respond to sensations.
The digestive system includes all the organs that are involved in taking in and processing food. It begins with the mouth and includes the esophagus, stomach, liver, pancreas, intestines, rectum, and anus.
The eyes of animals, including cats, function much like your eyes. Animals also develop many of the same eye problems that people can have, including cataracts, glaucoma, and other disorders. It is important for your cat to receive good eye care to protect its sight and allow it to interact comfortably with its environment.
The cardiovascular system includes the heart and the blood vessels (the veins and the arteries). The function of the heart is to pump blood. The right side of the heart pumps blood to the lungs, where oxygen is added to the blood. The left side pumps blood to the rest of the body, where oxygen and nutrients are delivered to tissues, and waste products (such as carbon dioxide) are removed. The heart is a hollow, muscular organ which, in mammals and birds, is divided into 4 chambers. The muscular tissue is called the myocardium. There are upper chambers on both the left and ride sides of the heart called the left and right atria (the plural form of atrium). There are also 2 lower chambers called the left and right ventricles.
Hormones are chemical messengers that have many different functions. The effects of hormones in the body are wide-ranging and varied. Some familiar examples of hormones include insulin, which is important in the development of diabetes, and estrogen and progesterone, which are involved in the female reproductive cycle (see Table: Major Hormones below)).
The immune system consists of a network of white blood cells, antibodies, and other substances that fight off infections and reject foreign proteins. In addition, the immune system includes several organs. Some, such as the thymus gland and the bone marrow, are the sites where white blood cells are produced. Others, including the spleen, lymph nodes, and liver, trap microorganisms and foreign substances and provide a place for immune system cells to collect, interact with each other and with foreign substances, and generate an immune response.
The urinary system or tract includes the kidneys, the ureters (tubes that connect the kidneys to the bladder), the bladder, and the urethra (the tube through which urine exits the body). The urinary system has several important functions. It gets rid of the waste products that are created when food is transformed into energy. It also maintains the correct balance of water and electrolytes (salts) needed for the body’s cells. Another key function is the production of erythropoietin and renin, which are important in maintaining healthy blood pressure, producing blood cells, and absorbing salt correctly. Finally, the urinary system processes vitamin D.
The respiratory system consists of the large and small airways and the lungs. When a cat breathes air in through its nose or mouth, the air travels down the trachea, which divides into the tubes known as the right and left bronchi, then into the smaller airways called bronchioles in the lungs. The bronchioles end in the small sacs called alveoli, where the barrier between the air and the blood is a thin membrane.
Metabolism refers to all processes in the body that break down and convert ingested substances to provide the energy and nutrients needed to sustain life. Foods, liquids, and drugs all generally undergo metabolic processes within the body. Many foods are complex materials that must be broken down into simpler substances, which in turn become “building blocks” for the body to use as needed. For example, protein is broken down into amino acids, which are used in several metabolic reactions. Enzymes made by the body are necessary for many metabolic processes. Whenever the function of an enzyme is affected, a metabolic disorder can develop. Metabolic disorders are important because they affect energy production or damage tissues. They may be genetic (inherited) or acquired. Acquired metabolic disorders are more common and significant.
The reproductive system is the group of organs that produce offspring. In both males and females, the reproductive system is composed of primary sex organs and primary regulatory centers. The primary sex organs are testes in the male and the ovaries and uterus in the female. The primary regulatory centers are in the brain. They control the production of hormones that in turn influence the functioning of the primary sex organs.
The skin is the largest organ of your cat’s body. It provides a protective barrier against the environment, regulates temperature, and gives your cat its sense of touch. Depending on the species and age, the skin may be 12 to 24% of an animal’s body weight. The skin has 3 main layers: the epidermis or outer layer, the dermis or middle layer, and the subcutis or innermost layer. Other important parts of the skin include skin appendages (such as hair and claws) and subcutaneous muscles and fat.
There are many disorders that can affect multiple parts of the body. These may be caused by bacteria, viruses, poisonous or toxic substances in the environment, and other health hazards. Disorders affecting multiple body systems can also be inherited or develop while the animal is still in the womb. Diseases or conditions that involve multiple organ systems may also be described as systemic or generalized.