Dogs and cats pose in a line.

Vetopedia is a glossary of terms used by vets in treating animals.


Association of American Feed Control Officials; an organization which sets standards for pet food ingredients and minimum daily requirements.

A region of the body between the chest and the pelvis; belly.

The insertion of a needle into the abdominal cavity to remove fluids.

A localized accumulation of pus; usually associated with infection.

ACE Inhibitor
Angiotensin-converting-enzyme (ACE) inhibitor: Drug which decreases the function of this particular enzyme. The angiotensin-converting-enzyme changes a compound called angiotensin I to angiotensin II. Angiotensin II is a potent blood vessel constrictor. ACE inhibitors, then, have the effect of dilating blood vessels, since less Angiotensin II is produced.

A fluid containing a high proportion of hydrogen ions, giving the liquid a sour taste. Measured by pH units, with 1 the most acid, and 14 the least acid. Chemical reactions in the body have to take place at or near neutrality, pH 7.

Adrenocorticotropic hormone. A hormone, secreted by the pituitary gland, which stimulates the adrenal gland to work.

Activated Charcoal
Charcoal which has been treated to increase its adsorptive power (ability to have chemicals adhere to it); used to treat various forms of poisoning.

Active Immunity
Immunity produced when an animal's own immune system reacts to a stimulus e.g., a virus or bacteria, and produces antibodies and cells which will protect it from the disease caused by the bacteria or virus. Compare with 'passive immunity.'

Having a sudden and generally severe onset. See also Chronic.

Addisons Disease
Addison's disease is also known as hypoadrenocorticism. It is a disease that results from a decrease in corticosteroid secretion from the adrenal gland.

A substance added to killed vaccines to stimulate a better immune response by the body. Common adjuvants contain aluminum compounds.

Adrenal Glands
Two small glands near the kidneys that produce many hormones required for life.

A hormone produced by the adrenal glands that elevates heart and respiration rates; also called 'epinephrine.'

Communication between the nerves and muscles that uses epinephrine as the 'messenger.' Adrenergic stimulation is what is involved in the 'flight or fight' response, which means the body is alerted to a danger of some sort and prepares to basically run or fight. Adrenergic stimulation results in an increased heart rate, sweating, and increased blood pressure.

A solid substance which attracts other molecules to its surface.

Medication formulated to kill adult forms of a parasite.

Needing oxygen to live. See also Anaerobic bacteria.

Aerobic Bacteria
Bacteria that require oxygen to survive and grow.

Clumping together.

An animal that is completely white because it lacks the ability to make pigment. Its eyes are pale blue or pink.

A protein in the blood responsible for the maintenance of osmotic (water) pressure in the blood; also binds (attaches) to large molecules in the blood and serves to transport them; produced by the liver; also called 'serum albumin.'

A hormone secreted by the adrenal gland that stimulates sodium (and therefore water) retention and potassium excretion; important in blood pressure maintenance.

Pertaining to food or the digestive tract.

A substance with very few hydrogen ions, and a pH over 7. Lye is strongly alkaline.

A substance that causes an allergic reaction, e.g., pollen.

A loss of hair or baldness.

The tiny microscopic areas of the lung where the actual exchange of oxygen and carbon dioxide into and out of the blood occurs. Also called alveolus and alveolar sacs.

A class of antibiotics which act by interfering with bacterial protein synthesis within the bacteria which results in the death of the bacteria. Antibiotics in this class include gentamicin (Gentocin), kanamycin, neomycin, streptomycin, tobramycin, and amikacin. Many of these antibiotics are not well-absorbed from the animal's digestive system, so are often administered as injections, or used topically.

Digestive enzyme, produced by the pancreas which breaks down carbohydrates and starches.

Anabolic Steroid
A type of steroid (not a corticosteroid like prednisone, cortisone, or dexamethasone) which promotes the building of tissues, like muscle.

Anaerobic Bacteria
Bacteria which only live in an environment in which there is no or little oxygen, e.g., Clostridium tetani which causes tetanus.

Pain relief.

Anamnestic Response
The faster and greater immune response produced by an animal who has previously encountered that specific antigen. Memory cells are responsible for this more efficient response. Also called 'secondary response.'

Anaphylaxis is a rare, life-threatening, immediate allergic reaction to something ingested or injected. If untreated, it results in shock, respiratory and cardiac failure, and death.

A hormone which produces male sexual characteristics, e.g., testosterone.

A condition in which the number of red blood cells present in the blood is lower than normal.

Loss of sensation or feeling; induced artificially with drugs to permit painful procedures such as surgery.

The x-ray of vessels after injecting a contrasting fluid.

Angiotensin-Converting-Enzyme Inhibitor
(ACE inhibitor) Drug which decreases the function of this particular enzyme. The angiotensin-converting-enzyme changes a compound called angiotensin I to angiotensin II. Angiotensin II is a potent blood vessel constrictor. ACE inhibitors, then, have the effect of dilating blood vessels, since less Angiotensin II is produced.

A condition in which the pupils of the eyes are not of equal size.

Loss of appetite.

Positioned in front of another body part, or towards the head of the animal. Opposite of posterior.

Medication which kills certain types of intestinal worms; dewormer.

Usually refers to drugs administered to kill or inhibit the growth of bacteria; not effective against viral infections.

Small disease-fighting proteins produced by certain types of cells called 'B cells.' The proteins are made in response to 'foreign' particles such as bacteria or viruses. These antibodies bind with certain proteins (antigens) on foreign particles like bacteria, to help inactivate them. See also Antigen.

Antibody Titer
A measurement of the amount of antibodies in the blood. The test to measure antibodies is usually performed by making a number of dilutions of the blood and then measuring at what dilution there is sufficient antibody to react in the test. For example, a titer of 1:8 (one to eight) means the blood can be diluted to one part blood and seven parts saline and still produce a positive reaction in the test. The higher the titer (1:16 is higher than 1:8), the more antibody is present.

Stopping the communications between certain nerves and muscles of the body including those of the gastrointestinal tract and heart. These nerves are called 'parasympathetic' nerves and do such things as constrict the pupils of the eye, stimulate contractions of the muscles in the intestine, and slow the heart rate. Anticholinergic drugs would have the effect, then, of dilating the pupil, slowing contractions of the intestines, and increasing the heart rate.

A drug that blocks the enzyme acetylcholinesterase; this results in stimulation of the parasympathetic nervous system.

Stopping the blood clotting process.

A drug used to prevent or decrease the severity of convulsions.

Antidiuretic Hormone
A hormone produced by the pituitary gland that reduces the production of urine in the kidneys and therefore prevents water loss; also called 'vasopressin.'

An agent that decreases or stops vomiting.

Drugs administered to kill or inhibit the growth of fungi (plural of fungus).

A molecular structure on surfaces of such particles as bacteria and viruses. This structure is recognized by the body as 'foreign' and stimulates the body to produce special proteins called antibodies to inactivate this foreign invader. See also Antibody.

An agent that kills protozoa, which are one-celled organisms such as Giardia.

Relieves itching.

A substance used to relieve fever.

A substance which inhibits the growth of bacteria, but does not kill them.

An agent that relieves or decreases spasms in muscle. The muscle could include 'smooth muscle' which is the type of muscle in intestines that causes them to contract and move food through the digestive system.

Cough suppressant.

The condition of complete failure in the function of the kidneys such that no urine is produced.

A muscular opening at the end of the digestive tract where fecal waste is expelled.

Aplastic Anemia
A serious condition in which red blood cells, white blood cells, and platelets are not produced in sufficient quantity.

The (usually commercial) captive raising of fish, corals, and other aquatic life for aquariums, food, and scientific purposes.

Aqueous Humor
The fluid found within the eyeball which provides nourishment to the interior eye structures and keeps the eyeball inflated.

A variation from normal heart rhythm.

Thick walled vessels that carry blood away from the heart to the lungs and body tissues; the pulmonary arteries carry deoxygenated blood to the lungs, but all other arteries carry oxygenated blood.

Inflammation and swelling in the joints; has multiple causes including lameness.

Pertaining to a joint.


Fluid accumulation in the abdomen.

Withdraw fluid or cells through the use of suction - usually the suction produced by pulling back on the plunger of a syringe attached to a needle which is inserted into the area to be sampled. Also the breathing in of a fluid or foreign substances.

A term used to decide a condition in which no symptoms are present.

A lack of muscle coordination, usually causing an abnormal or staggered gait.

A coral island consisting of a reef surrounding a lagoon.

An allergy to something that is inhaled such as pollen or house dust. Also called 'inhalant allergy.'

Adenosine triphosphate; a compound used for energy by cells.

Atrial Fibrillation
A heart condition in which the atria (chambers of the heart that receive the blood) contract rapidly, irregularly, and independently of the ventricles (the chambers of the heart that pump the blood). This greatly decreases the efficiency of the heart and its ability to move blood.

Atrial Flutter
A heart condition in which the atria (chambers of the heart that receive the blood) contract rapidly, irregularly, and independently of the ventricles (the chambers of the heart that pump the blood). This greatly decreases the efficiency of the heart and its ability to move blood.

(Plural atria) The two chambers of the heart that receive blood. The right atrium receives blood from the body. The left atrium receives oxygenated blood from the lungs.

An abnormal decrease in size of an organ or tissue.

Weakened. An attenuated virus is one which has been changed such that it will no longer cause disease. An attenuated virus would be used in a modified live vaccine.

To listen for sounds produced within the body, usually with the aid of a stethoscope.

A condition in which the immune system attacks the body's own tissues. To properly function, the immune system must identify foreign substances such as bacteria, viruses, parasites, slivers, etc., and it must be able to distinguish normal body tissue from these foreign substances. If it fails to distinguish the difference, it attempts to destroy the tissue it wrongly identifies as foreign. For example, in autoimmune hemolytic anemia, the body destroys its own red blood cells. In rheumatoid arthritis it attacks the cells in the joints.


The presence of increased nitrogenous (containing nitrogen) waste products in the blood as a result of kidney malfunction.


B Cell
Also called 'B lymphocyte.' The type of lymphocyte which produces antibody. Compare with 'T cells.'

A description of an agent that kills bacteria.

A description of an agent that stops the growth (reproduction) of bacteria, but does NOT kill them.

Microscopic organisms that lack nuclei and other organelles; pathogenic species cause disease, while nonpathogenic species are harmless.

A mild illness or non-malignant form of a tumor. Benign tumors usually have well defined edges and tend to grow slowly.

Beta Blockers
Heart medications which block certain receptors in the heart called beta receptors. The beta receptors receive signals which generally increase the heart rate. If the heart rate is abnormally fast and uneven, beta blockers will help stabilize the rate and rhythm of contractions.

A plant pigment which can be converted to Vitamin A by many animals, but not by cats.

Enzymes produced by some bacteria which inactivate certain types of penicillin, thus making the bacteria resistant to them.

On both sides.

A liquid produced by the liver, stored in the gall bladder, and dispensed into the small intestine as needed; aids in the digestion and absorption of fats.

Bile Acids
Certain compounds produced by the liver, bound to amino acids, and excreted in the bile to aid in the digestion of fats.

An orange-yellow pigment in bile that is a product of red blood cell breakdown; it is normally excreted with the urine or feces, and a buildup in the body can cause jaundice.

The surgical removal of a small amount of abnormal tissue, usually of tumors, for diagnosis.

A female dog.

A sac that receives and holds a liquid until it is excreted, e.g., urinary bladder, gall bladder; in fish, the swim bladder holds air.

Spasm of the eyelids often resulting in complete closure of the lids due to eye pain, such as seen with a scratch on the cornea.

Filling of the stomach with air.

Blood Gases
Gases, such as oxygen or carbon dioxide, that are in the blood.

Blood Glucose
A graph of blood glucose levels over time. At the time of insulin injection, and at regular intervals throughout the day, the level of glucose in the blood is determined through laboratory testing.

Bone Marrow
A soft tissue composed of blood vessels and connective tissues found at the center of bones; the primary function is blood cell production.

Bone Marrow Suppression
A condition in which the cells of the bone marrow which produce red blood cells, white blood cells, and platelets are inhibited. This may result from the use of certain drugs, such as anti-cancer agents.

The sound of gas moving through the intestine; bowel sounds.

An abnormal slowing of the heart rate.

The plural of bronchus, the large air passages of the lungs.

The small airways in the lung that come off of the larger bronchus; bronchioles are 1 mm or less in diameter.

Medication which opens up the main air passages to the lungs.

A tool designed to facilitate inspection of the trachea and bronchi; used in both diagnostic and therapeutic procedures.

The internal inspection of the trachea and bronchi using a bronchoscope.

A condition in which the muscles surrounding the air passages to the lungs contract, narrowing the passages.

Short for 'blood urea nitrogen,' a blood test that estimates kidney function.


Extreme weight loss.

The hardening of tissue through the influx of calcium, usually as a result of chronic inflammation.

(Plural calculi) Abnormal stone-like structure(s) usually composed of mineral salts, e.g., a bladder calculus is the same thing as a bladder stone.

The unit of measurement of energy derived from digested food. Fat contains about twice as many calories per gram as protein or carbohydrate.

A malignant tumor.

A certain genus of yeast which can cause disease in humans and animals; an infection with Candida is called candidiasis.

Pertaining to dogs.

The upper shell of a turtle or tortoise.

Compounds made up of chains of sugar units. Simple carbohydrates include table sugar (sucrose), milk sugar (lactose), and fruit sugar (fructose). Complex carbohydrates are very long chains held together by bonds that may not be digestible in the stomach and intestine of a carnivore. Starch is a digestible complex carbohydrate. Seed hulls such as oat bran are digestible by ruminants and horses, but not carnivores.

A substance which causes cancer.

A malignant cancer that arises from the epithelial tissues of the body such as the skin, intestinal tract, and bladder.

Related to the heart.

Diseases of the heart muscle; does not include diseases of the valves of the heart or congenital defects.

Relating to the heart and lungs.

Related to the heart and blood vessels.

An animal whose natural diet includes meat.

The wrist (front leg) of dogs and cats.

An animal which harbors an infectious organism, such as a virus, bacteria, or parasite. The animal does not appear ill, but can still transmit the organism to other animals by direct contact or releasing the organisms (bacteria, protozoa, viruses) into the environment in the stool, urine, respiratory secretions, or vaginal discharges.

The removal of the sex organs making the animal incapable of reproduction; the correct use of the word can be used to describe both male and female animals, but it is commonly used to describe only males.

A cloudiness of the lens of the eye, reducing vision and giving the eye a pearly appearance.

A directional term used to refer to an area more toward the cauda, or tail region; opposite of cranial.

Caval Syndrome
Disease caused by large numbers of worms in the right side of the heart and vena cava, which results in blood circulation problems in the liver leading to the breakdown of red blood cells, anemia, weakness, and collapse.

A blind sac that opens into the colon; found in many animals.

Cell-Mediated Immunity
The immunity that is the result of either special lymphocytes directly killing the foreign invader, or lymphocytes (T cells) releasing special chemicals which activate macrophages to kill the invader. Compare with 'humoral immunity.'

A machine that rapidly spins liquid samples and separates out the particles by their density.

A portion of the brain, located on the brainstem, that controls coordination.

Relating to the part of the brain known as the cerebrum.

The largest portion of the brain that performs all higher cognitive functions and is situated in the front part of the cranial cavity.

Binding of a substance to a metal, thus helping the body to remove it.

Treatment of a disease with chemical agents (drugs); the term is most commonly used to describe the treatment of cancer with medication.

(Plural choanae) An opening between the nasal cavity and oropharynx (mouth) in birds and reptiles.

Inflammation of the gall bladder, bile ducts, and liver.

Inflammation of a bile duct; see cholecystitis.

Inflammation of the gallbladder; see cholangitis.

Decreases the activity of enzymes which break down cartilage in a joint.

Chondroprotective Agent
A nutritional supplement that protects cartilage.

Of a long duration: a chronic illness persists for weeks, months, or even for the life of animal. See also acute.

Chronic Superficial Keratitis
A chronic condition of the eye in which blood vessels grow across the cornea (the clear surface of the eye). The cornea looks hazy and sometimes reddened; it may eventually take on a dark pigment. This condition is also called pannus.

A liver disease caused by the replacement of damaged cells with connective tissue; severe scarring can eventually cause liver failure.

Class I, II, III, IV Medications
Drugs are classified by the Drug Enforcement Administration of the Department of Justice depending upon such criteria as the potential for human abuse.

Clinical Study
A planned examination of the effectiveness of a new drug or treatment for a disease as compared to a control group not receiving the treatment; also called a clinical trial.

A common tube-like structure through which feces, urine, and reproductive fluids/eggs pass in birds, turtles, and other lower vertebrates.

Clotting Factors
Protein components in the blood which help it to clot. Clotting is a complex mechanism. In addition to platelets, clot formation is the result of a long chain of chemical reactions carried out by individual molecules called 'clotting factors.' Each factor is numbered such that factor I leads to a reaction with factor II forming a new substance. This then reacts with factor III and so on to factor XII.

The uninterrupted series of eggs laid by a hen, usually 2-6 depending on the bird species.

Central nervous system. Includes the brain, spinal cord, and the nerves leading from them.

The process of clotting.

A condition affecting the blood's ability to form a clot.

A one-celled parasite in the category of protozoa. In dogs and cats, coccidia are generally parasites of the intestinal tract.

Cognitive Dysfunction
A common medical condition in older dogs that results from abnormal brain function, causing certain behavior changes such as disorientation, housebreaking problems, and changes in sleeping patterns and interactions with others.

Having a body temperature that is not regulated internally, but varies with the environmental temperature. Turtles, lizards, and snakes are cold-blooded.

An infection or inflammation of the colon.

A part of the digestive tract, specifically the part of large intestine that extends from the cecum to the rectum.

The antibody-rich first milk produced immediately before and after giving birth.

Being in a state of unconsciousness.

A blackhead, usually the result of a plugged gland within the skin.

Complete Blood Count
A count of the total number of cells in a given amount of blood, including the red and white blood cells; often referred to as a 'CBC,' it is one of the most common tests done to check for abnormalities of the blood.

Computerized Tomography Scan (CT Scan)
A radiological imaging procedure that uses x-ray pictures to produce "slices" through a patient's body; also called a computerized axial tomography (CAT).

The onset of pregnancy, when the fertilized egg attaches to the uterus.

A characteristic of an animal that is present at birth. It may be inherited or induced by events that occur during pregnancy.

A thin membrane which lines the inside of the eyelids and covers part of the eyeball.

An inflammation of the lining of the eyelids; may cause pain, redness, itching, and a discharge.

A condition in which the movement of food through the digestive system is longer than normal; often results in hard, dry stool.

Contrast Agents
A substance given orally or injected into a patient that makes the affected tissue easier to identify on an x-ray.

An injury to underlying tissues without breaking the skin; a bruise.

Eating dung or fecal matter; normal behavior in some animals, such as rabbits.

Core Vaccine
Vaccine which should be given to all animals of certain species, example, parvovirus vaccine in dogs or panleukopenia in cats (see noncore vaccine).

The clear part of the front of the eye which allows light in.

Hormones produced by the adrenal gland which are important to almost every function of cells and organs. They are divided into two groups: glucocorticoids and mineralocorticoids. Glucocorticoids regulate protein, carbohydrate, and fat metabolism. Mineralocorticoids regulate electrolyte balances.

The main glucocorticoid; a hormone naturally produced by the adrenal gland; it is synthesized commercially as hydrocortisone and is used to reduce inflammation.

Estrogen-like substance produced by certain plants such as alfalfa; types of phytoestrogen.

Estrogen-like substances produced by certain plants such as alfalfa; types of phytoestrogen.

A directional term used to refer to the area near the cranium, or head region; opposite of caudal.

An organ between the esophagus and stomach of many domestic birds, which serves as a temporary food storage organ.

Area of dried fluid or cells on the skin. The fluid may have been blood, serum, pus, or medication.

The process in which a sample of fluid or tissue is taken from an animal and placed in special media which allows the bacteria, virus, etc., to grow (reproduce) in the laboratory.

Cushings Disease
Cushing's disease is also known as hyperadrenocorticism. It is a disease that results from an increase in corticosteroid secretion from the adrenal gland.

Relating to the skin.

Bluish or grayish color to the skin and gums which occurs when the animal has insufficient oxygen.

An abnormal sac-like structure that is lined with cells which produce a liquid or thick material.

Inflammation of the urinary bladder.

Compounds produced by certain cells, which act as messengers to control the action of lymphocytes and other cells in an immune response.

The study of cells; often refers to the microscopic examination of a sample taken from the skin or lesion to look for the cause of a condition.

Substances which make up the inside of a cell and surround the nucleus of the cell which contains the genetic material.


Drug Enforcement Administration. The federal agency which regulates the manufacture, dispensing, storage, and shipment of controlled substances including medications with human abuse potential.

Remove injurious material.

The elimination of feces from the rectum.

A condition in which the body loses more water than it takes in.

Relating to the skin.

An inflammation of the skin.

Fungus that causes ringworm; include Trichophyton, Microsporum, and Epidermophyton.

The removal of the anal sacs of a carnivore to prevent the animal from releasing the very strong-smelling secretion.

A commonly used name for glucose (sugar) solutions given intravenously to treat fluid or nutrient loss.

Diabetes Mellitus
A metabolic disease caused by failure of the pancreas to produce insulin, a hormone that allows blood sugar (glucose) to be taken up by cells that require it for function.

Diagnostic Tests
Procedures run to find the cause of disease or discomfort; tests used to make a diagnosis.

A process which involves removing waste products from the body.

A condition in which the movement of food through the digestive system is faster than normal; often results in the frequent passing of abnormally loose or watery stool.

The stage of the estrus cycle which occurs after the animal goes out of heat (also called Diestrous).

Dietary Indiscretion
Eating what one should not. Dogs with dietary indiscretion eat garbage, dead fish on shore, etc.

Expressed as a percent, is a measure of the content of food that is retained in the body after food is eaten. The difference between the weight of food eaten and the weight of stool produced, divided by the weight of the food.

Digestive System
The organ system including the mouth, teeth, tongue, esophagus, stomach, intestines, and various glands that functions to ingest, digest, and absorb nutrients.

Digitalis Glycosides
Class of drugs including digitoxin and digoxin, which are drugs derived from the Digitalis purpurea plant, and used in the treatment of congestive heart failure.

Dilated Cardiomyopathy
A heart condition in which the heart enlarges, but the heart muscle becomes thinner.

Single-celled algae, mainly marine and often with a cellulose shell; some species may be luminescent, and some cause the red tides that are extremely toxic to marine life.

The act of using chemicals or heat to kill germs.

Canine distemper is a viral disease that causes a severe and often fatal systemic illness in dogs and their close relatives. Distemper is also fatal in animals such as raccoons, and mustelids including skunks, mink, and ferrets.

Increase in urine production.

Agent which increases the secretion of urine, ridding the body of excess fluid.

Active during the day, opposite of nocturnal, which means active during the night.

Deoxyribonucleic acid, the chemical compound that occurs in cells and is the basic structure for genes.

Domestic Animal
An animal that has been housed and fed by man for generations and has little fear of man as a result.