Glossary

Glossary of Some Commonly Used Veterinary Medical Terms

Abdomen part of a mammal's body between the thorax and the pelvis. The belly. The cavity of this part of the body.

Abscess localized collection of pus in a cavity formed by disintegration of tissues.

Acute having a short and relatively severe course of development. Opposite of chronic.

Adhesion abnormal union of two adjacent tissues or organs.

Aerobic requiring air or free oxygen to live and grow.

Alimentary canal tubular passage functioning in the digestion and absorption of food. In most animals, beginning at the mouth and ending at the anus.

Anaerobic living or growing best in the absence of free air or oxygen.

Anemia deficiency of hemoglobin, usually accompanied by reduced number of red blood cells.

Anorexia lack of or loss of appetite.

Ante mortem before death. Anterior toward the front or head.

Antibiotic any of a large group of soluble chemical substances produced by various micro-organisms and fungi. Antibiotics inhibit the growth of or destroy bacteria and other microorganisms.

Antigen specific biological substance inoculated into an animal to stimulate resistance or immunity to a specific disease.

Antibody the very specific biological substance that the body itself manufactures to combat specific diseases following a vaccination or following an attack of a disease.

Antiseptic an agent that destroys or severely inhibits micro-organisms that cause disease, decomposition or fermentation.

Antiserum serum from blood containing one or more specific antibodies. It is injected into animals to give immediate though very short term protection.

Antitoxin antibody that neutralizes toxin of a bacteria.

Aqueous watery, or prepared with water.

Artery vessel through which blood passes from the heart to various organs or parts of the body.

Arthritis inflammation of a joint and its adjacent tissues.

Aseptic free from microorganisms that cause disease, fermentation or putrefaction.

Ataxia failure or irregularity of muscular action producing a stumbling or staggering gait.

Atrophy shrinking or wasting away of a tissue or organ.

Attenuated weakening of viruses in a laboratory so they will not produce disease, but will still produce antibody production when used as a vaccine.

Autoimmunity production by an animal of an allergic reaction to its own tissues which may produce clinical disease.

Bactericidal having properties that destroy or kill bacteria.

Bacterin killed or inactivated bacteria used as vaccines.

Bacteriostatic inhibiting or retarding bacterial growth.

Bacterium, bacteria single-celled organism that multiplies by simple division. Can be either spherical, rod-shaped or spiral. Some are beneficial and others cause disease.

Benign not malignant, not likely to recur or metastasize.

Bladder stretchable membrane sac that temporarily stores urine secreted by the kidneys.

Cancer malignant types of tumors that have a tendency to spread to other tissues or organs (metastasize).

Capillary smallest vessel of the circulatory system. Capillaries connect the smallest arteries (arterioles) and the smallest veins (venules). Walls of the capillaries are in direct contact with individual cells of the tissues.

Carcinoma malignant type of cancer composed of epithelial or gland cells that have a tendency to spread (metastasize) quickly.

Carrier infected animal (or person) that harbors a specific infectious agent in the absence of discernible clinical disease and serves as a potential source of infection for other animals.

Cartilage a specialized fibrous, elastic or hyaline connective tissue found in many locations in the body. Cartilage ay form the shape of a part, such as on the ear and the tip of the nose, or may serve as a soft, somewhat flexible end of a long bone, such as on the distal end of the ribs.

Caudal of, toward, attached to or near the tail.

Cecum, ceca blind pouches at the junction of small and large intestines. Poultry have two ceca.

Cellulitis inflammation of cellular tissue, especially purulent (consisting of pus) inflammation of the loose subcutaneous tissue.

Celsius name of a Swedish astronomer who calibrated a thermometer to indicate the freezing point of water at 0 and the boiling point at 100 . Also called centigrade, because of the 100 degrees between these two points.

Cervical of or pertaining to the neck. Also of or pertaining to the cervix.

Chronic persisting or continuing over a long period of time. The opposite of acute.

Cirrhosis disease characterized by degeneration of liver tissue with a replacement by hard though fibrous, connective tissue. Hardening or fibrosis of any tissue or organ, but especially the liver.

Clinical based on actual observation of signs or symptoms.

Cloaca portion of the lower end of the avian digestive tract that provides a passageway for products of the urinary, digestive and reproductive systems.

Coccidiostat any of a group of chemical agents mixed in feed or drinking water to control coccidiosis.

Coccygeal of, or pertaining to, vertebrae of the tail.

Comatose state of unconsciousness from which a subject cannot be aroused, even by powerful stimulations.

Communicable disease illness due to a specific infectious agent or its toxic products arising through transmission of that agent or its products from a reservoir to a susceptible host.

Congestion presence of abnormally increased amounts of blood in an organ or tissue.

Conjunctiva mucous membrane that lines inner surface of the eyelids.

Conjunctivitis inflammation of the conjunctiva.

Connective tissue tough fibrous tissue that supports and connects other tissues of an animal body.

Contagious capable of spreading from one animal to another.

Cranial of, toward, attached to or near the head.

Cyanosis bluish discoloration of tissues due to reduced oxygen in the blood.

Cyanotic adjective of above.

Cyst any sac or bag-like structure, normal or abnormal, especially one that contains a liquid or semi-solid material.

Dewclaws hard horny structures above the hoof on the rear surface of the legs of cattle, swine and sheep. Rudimentary or vestigial toes also on dogs, etc.

Disinfection killing infectious agents outside the body by chemical or physical means, directly applied.

Distal farthest away or most distantly removed from the center or point of attachment.

Dorsal upper surface.

Edema accumulation of serous fluid in intercellular spaces of a tissue.

Emaciation wasted condition of a body characterized by slimy degeneration of fatty tissues and serous infiltration of the muscles.

Embryo in livestock, very earliest stage of individual development within the uterus. The embryo grows and develops into a fetus. In poultry, developing of the individual within the eggshell.

Emphysema swelling or inflation due to presence of air in the interstitial connective tissue framework of the lung.

Encephalitis an inflammation of the brain.

Endemic constant presence of a disease or infectious agent within a given geographic area; may also refer to usual prevalence of a given disease within such area.

Endocarditis inflammation of the endocardium, the tissue that lines interior chambers of the heart.

Enteritis inflammation of the intestine, especially the small intestine.

Enterotoxin toxin that is specific for the cell of the intestinal mucosa.

Enzyme any of a series of complex organic catalysts produced by living cells that initiate, sustain or accelerate biological chemical reaction, especially the chemical reactions of digestion.

Epidemic occurrence in a community or region of cases of a human illness (or an outbreak) clearly in excess of normal expectancy and derived from a common or a propagated source.

Epidemiology science or study of the causes and control of epidemics.

Epizootic any widely diffused and rapidly spreading disease of animals. (Epidemic for humans).

Esophagus tubular structure, which extends from the pharynx to the stomach, through which food passes as it is swallowed.

Estrus periodic sexual excitement of most female mammals during which there is a time that the female will accept mating. Same as heat.

Feces bowel movements, excrement from the intestinal tract.

Fetus later stage of individual development within the uterus. Generally, the new individual is regarded as an embryo during the first half of pregnancy, and as a fetus during the last half.

Fistula abnormal passageway or tube extending between two organs or draining an internal organ to outside surface of the body.

Flaccid flabby, limp, relaxed, without firm shape or consistency.

Fluke trematode flatworm parasite of humans, animals and birds. A common parasite of domestic livestock is the liver fluke Fasciola hepatica. Different species of flukes may live in the bloodstream, intestine or lung.

Fungus any of a large group of microscopic or larger plants that do not contain chlorophyll and that reproduce by forming spores. Examples include mildews, molds and mushrooms.

Gastritis inflammation of the stomach.

Gestation state, process or period of intrauterine development from conception to birth.

Heat see estrus.

Helminth category of worms.

Hepatic of or pertaining to the liver.

Hepatitis inflammation of the liver.

Hormone chemical substance, produced in the body, that has a specific effect on the activity or function of a certain organ.

Host human or other living animal, including birds and arthropods, that affords food or a home to an infectious agent under natural conditions.

Hypertrophy morbid enlargement or overgrowth of an organ or part due to increase in size of its constituent cells.

Icterus abnormal accumulation of greenish and yellowish bile pigments in tissues.

Immunity active immunity is when an individual has manufactured its own antibodies to combat a disease either from having the disease or from being vaccinated. Passive immunity is when an individual acquires the antibodies produced by another individual such as from the mother's milk, when in the uterus, or from an injection of antiserum.

Inapparent infection presence of infection in a host without occurrence of recognizable clinical signs or symptoms. Inapparent infections are only identifiable by laboratory means. Synonym: Sub-clinical infection.

Inbreeding breeding of closely related animals. Usually done to bring out specifically wanted traits.

Incidence number of cases of a disease diagnosed during a specific time frame.

Incubation period time interval between exposure to an infectious agent and appearance of the first sign or symptom of the disease in question. Also, the time elapsed between a bird's laying an egg until it hatches.

Infection entry and development or multiplication of an infectious agent in the body of humans or animals.

Infectious capable of invading and growing in living tissues. Used to describe various pathogenic micro-organisms such as viruses, bacteria, protozoa and fungi.

Infectious agent an organism, chiefly a micro-organism but including worms, that is capable of producing infection or infectious disease.

Inflammation reaction of a tissue to irritation or injury. Inflammation is characterized by pain, redness, heat (fever), swelling and loss of function.

Ingest anything taken into the stomach.

Inhibitor agent that slows or prevents a chemical reaction.

Jaundice see icterus.

Laceration jagged tear or wound.

Lactation secretion of milk by a mammary gland.

Lesion internal visible morbid change in the structure, color or size of an organ or part of the body. It may be microscopic in size.

Leukosis serious disease of the blood-forming organs, characterized by marked increase in number of white blood cells in the circulating blood, together with enlargement and quick growth of lymphoid tissue of the spleen, lymph glands and bone marrow.

Lymph clear yellowish, slightly alkaline fluid contained in lymphatic vessels.

Lymph node any of many gland-like structures located along the course of the lymph vessels. The nodes produce lymphocytes and function as a filter for the fluid lymph.

Malignant tending to become progressively worse, recurring or spreading. Opposite of benign.

Mammary gland gland that secretes milk.

Mange--communicable dermatitis of humans and animals caused by minute mites that burrow into the skin to feed, live and reproduce.

Mastitis--inflammation of a mammary gland.

Melanin dark (black or brown) pigment found in the skin, hair, certain parts of the eye and brain, and in certain of the darker (melanotic) tumors.

Melanosis condition characterized by deposition or accumulation of abnormally large amounts of pigment melanin.

Metabolism sum of all physical and chemical processes by which living organized substance is produced and maintained, and also the transformation by which energy is made available for use by the organism.

Metastasis transfer of disease from one organ to another not directly connected with it. It may occur as a result of transfer of pathogenic organisms as in tuberculosis, or as a result of cells, as in cancer.

Milk fever see parturient paresis.

Mites very small (in many cases microscopic) jointed-legged creatures very similar to ticks. Mites are found everywhere, and infest both animals and plants. Mites that burrow into the skin of animals cause mange.

Morbid affected by, caused by, causing or characteristic of disease.

Morbidity rate number of individuals in a group that become ill during a specified time.

Moribund in dying state, near death.

Mortality rate number of individuals that die from a disease during a specified time, usually one year.

Mucosa or mucous membranes membranes that line cavities of the body that are exposed to air, and lining of the intestinal tract.

Mucus slimy exudate of the mucous membranes.

Myocardium heart muscle; the middle and thickest layer of the heart wall, composed of cardiac muscle.

Mycosis any disease caused by a fungus.

Nares external openings of the nasal passages.

Necrosis death of a tissue, usually as individual cells, groups of cells or in small localized areas.

Nematode class of roundworms or threadworms, such as hookworms, ascarids.

Neoplasm new growth of different or abnormal tissue; a tumor.

Nephritis inflammation of the kidney.

Noxious unpleasant, disagreeable.

Organoleptic making an impression on, or stimulating, any of the special senses: sight, smell, taste and touch.

Osteoporosis abnormal condition of the bone characterized by increased size, density and brittleness.

Osteoporosis abnormal rarefaction or thinning of the bone, making it weaker.

Oviduct tubes through which the egg passes from the ovary to the uterus or cloaca. In poultry, the shell is built around the egg in the cloaca.

Palpation examining a tissue or organ by the sense of touch.

Parasite plant or animal that lives on or within another organism from which it derives sustenance or protection without compensation.

Paresis partial or incomplete paralysis.

Parturient paresis partial paralysis that occurs at or near time of giving birth to young and beginning lactation. The mother mobilizes large amounts of calcium to produce milk to feed newborn, and blood calcium levels drop below the point necessary for impulse transmission along the nerve trucks. Commonly called "milk fever."

Parturition act of giving birth or delivering the young.

Pasteurization process of heating a food material, usually a liquid, to a specific temperature for a specific length of time. This heating process destroys some pathogenic bacteria and significantly delays development of others. Pasteurizing temperatures are not high enough to coagulate protein or caramelize sugar components of the liquid.

Pathogen disease agent.

Pathogenic--capable of producing disease or developing pathology.

Pericarditis inflammation of the sac surrounding the heart and the roots of the great blood vessels of the heart.

Pericardium thin tough connective tissue membrane that encloses the heart in a sac-like or bag-like structure.

Peritoneum thin serous membrane located in the abdominal cavity. Parietal peritoneum lines walls of the cavity. Visceral peritoneum covers outer surfaces of abdominal viscera and organs.

Peritonitis inflammation of the peritoneum (see above).

Phlebitis inflammation of the veins.

pH number number that indicates acidity or alkalinity of a solution. Number 7 indicates a neutral (non-reactive) solution. Numbers above 7 indicate an alkaline solution, and numbers below 7 indicate an acid solution.

Physiological of or relating to normal body, organ or tissue function.

Pleura thin serous membrane located in the thoracic cavity. Parietal pleura lines inside surface of the rib cage. Visceral pleura covers outer surfaces of the lungs.

Pleuritis inflammation of the pleura. "Pleurisy" is an old name for this condition.

Pneumonia inflammation of the lungs, usually involving one or more lobes, that causes consolidation of lung tissue and usually a generalized toxemia.

Pneumonitis condition of localized acute inflammation of the lung without gross or generalized toxemia.

Post mortem of, pertaining to or occurring in the time following death.

Potable fit or suitable for drinking. This term is used to describe water supplies that have been tested and determined to meet or exceed the appropriate health authority standards for drinking water.

Prevalence number of cases of disease in a specific group at a particular time.

Protozoa single-celled microscopic animal living chiefly in water. Can be parasitic or beneficial. The common amoeba is an example.

Protein any of a group of complex organic nitrogenous compounds, usually composed of alpha-amino acids, that form the principal constituents of cell protoplasm in animal and plant tissues.

Proteolytic used to describe substances, usually enzymes, that attack or digest complex proteins, resulting in simpler proteins or amino acids.

Proventriculus true or glandular stomach of poultry, lying between the ingluvies (crop) and the ventriculus (gizzard).

Purulent full of, containing, forming or discharging pus.

Pus liquid product of inflammation composed of dead white blood cells (leukocytes) and cellular fluids.

Raptors birds of prey, such as eagles, falcons, hawks, owls.

Reactor animal that has reacted positively to a test for an infectious disease, such as tuberculosis or brucellosis.

Renal of, pertaining to or located near the kidney.

Reservoir of infectious agents any humans, animals, arthropods, plants, soil or inanimate matter in which an infectious agent normally lives and multiplies, and on which it depends primarily for survival and reproduces itself in such a manner that it can be transmitted to a susceptible host.

Resistance sum total of body mechanisms that interpose barriers to the progress of invasion or multiplication of infectious agents or to damage by their toxic products.

Rhinitis inflammation of the mucous membranes lining the nasal passages.

Rigor mortis stiffness or rigidity that occurs soon after death as a result of coagulation of cell protoplasm proteins.

Ruminant animal that has four-compartment stomach and chews a cud of food. Cattle, sheep, goats, deer and elk are ruminants.

Salpingitis inflammation of the oviduct.

Scrotum pendulous skin 3ac that encloses and contains the testicles.

Semi-comatose state of very low consciousness, approaching total unconsciousness or coma.

Septic of or resulting from absorption of poisonous putrefactive material.

Septicemia pathogenic organisms, their toxic product and poisonous putrefactive material absorbed into and distributed throughout the body by the circulatory system.

Serological, serologically; pertains to blood serums (sera) with regard to tests for antibodies against specific diseases.

Serosa (serous membrane) thin membrane that lines most of the closed cavities of the body and covers the outer surface of the viscera. The pleura and peritoneum are serous membranes.

Serotype classification of a micro-organism as determined by kinds of antigens it contains.

Serous resembling or composed of blood serum.

Serum clear liquid portion of the blood.

Sign any objective evidence of a disease.

Sinus--cavity or hollow space.

Sinusitis inflammation of a Sinus cavity. Dehorning cattle often produces a frontal sinusitis.

Spastic pertaining to or affected by spasm or sudden uncontrollable muscular contractions.

Spinal canal canal or tube formed by vertebral arches containing the spinal nerve cord.

Spinal cord thick trunk of nerve tissue that extends down spinal canal from base of the brain to pelvic region.

Spleen large, highly vascular, ductless visceral organ in upper left abdomen, laying near or across surface of the stomach. The spleen has a complex function in modifying and regulating cellular components of the blood.

Spore seed of microscopic plants, such as fungi. Also, inactive or resting form of certain bacteria.

Sterile completely free of living organisms.

Sternum thin structure of bone and cartilage that forms ventral surface rib cage and serves as an attachment for distal ends of the ribs. Commonly called keel or breastbone when referring to poultry.

Stifle joint between the hip and the hock. Corresponds to knee of humans.

Subclinical see inapparent infection.

Subcutaneous located or attached beneath the skin.

Suppuration formation or discharge of pus.

Systemic of, or involving, the entire body.

Tendon tough, fibrous connective tissue at ends of muscle bundles that attach muscle to bones or cartilage structures.

Thorax--cavity enclosed by the rib cage and the diaphragm. The chest.

Toxemia generalized poisoning due to absorption and circulation of bacterial products (toxins) formed at a localized source.

Toxin a poison. Frequently used to refer specifically to a protein or conjugated protein substance produced by plants, certain animals and pathogenic bacteria that is highly toxic for other living organisms.

Toxoid a portion of bacterial toxin that has no toxicity but still retains ability to stimulate production of antitoxin when injected.

Trauma wound or injury that injures and destroys tissue.

Trematode see fluke.

Tumor mass of new tissue that persists and grows independently of its surrounding structures and has no physiologic function. A neoplasm. Tumors may be classed as benign or malignant.

Udder mammary glands of cattle and certain other animals. The bovine udder consists of four mammary glands. The equine,

ovine and caprine udders consist of two mammary glands. May be called "bag" or "dug."

Ulcer a loss of substance on a cutaneous or mucous surface with an erosion, disintegration and necrosis of the tissues.

Uremia an intoxication (poisoning) caused by accumulation in the blood of waste materials normally eliminated in urine. Uremia is a result of inadequate function of the kidneys.

Uterus hollow muscular abdominal organ of female animals in which the fertilized ovum is implanted and the embryo and fetus are protected and developed. The womb.

Vaccines products containing high numbers of weakened or killed organisms known to cause a particular disease. They are specific in that a separate vaccine must be used for immunization against each disease.

Vector carrier. A term applied to flies, mosquitoes, ticks, etc., that are capable of transmitting a disease.

Vehicle anything that can mechanically carry disease organisms from one source animal to another, such as clothing, food, water, dust.

Vein vessel through which blood passes from various organs or parts back to the heart.

Ventral on, or located toward, the lower or bottom surface.

Vertebrae bones that make up the spinal column, extending from the head to the tail.

Vesicle small bladder or sac containing liquid. A blister.

Vesicular disease a disease that includes development of fluid-filled vesicles or blisters in outer layers of the skin or mucous membranes. Vesicles break, leaving raw erosions or ulcers. Vesicular diseases of animals include foot-and-mouth disease, vesicular stomatitis, swine vesicular disease, and vesicular exanthema.

Vestigial of, or pertaining to, a mark, trace or visible evidence of something no longer present or in existence.

Virus ultra-microscopic bundle of genetic material capable of multiplying only in living cells. Viruses cause a wide range of disease in plants, animals and humans, such as rabies and measles.

Viscera internal organs and glands contained in the thoracic and abdominal cavities.

Viscous sticky, thick, syrupy.

Zoonosis infection or infectious disease transmissible under natural conditions from vertebrate animals to humans. May be enzootic or epizootic (see endemic and epidemic).

Larry D. Mark is Public Affairs Officer, Animal and Plant Health Inspection Service.