Veterinary Medical Diseases and Problems A to Z
Veterinary Medical Problems and Diseases A to Z is a list of terms sometimes used by veterinarians during the diagnosis and treatment of your pet. If you don’t understand something hat we say, ask, or check below, for details.
Abscess A localized accumulation of pus; usually associated with infection.
Addison’s 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.
Anisocoria A condition in which the pupils of the eyes are not of equal size.
Anorexia Loss of appetite.
Anuria The condition of complete failure in the function of the kidneys such that no urine is produced.
Anus 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.
Ataxia A lack of muscle coordination, usually causing an abnormal or staggered gait.
Atopy An allergy to something that is inhaled such as pollen or house dust. Also called 'inhalant allergy.'
Arrhythmia A variation from normal heart rhythm.
Arthritis Inflammation and swelling in the joints; has multiple causes including lameness.
Ascites Fluid accumulation in the abdomen.
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.
Atrophy An abnormal decrease in size of an organ or tissue.
Azotemia The presence of increased nitrogenous (containing nitrogen) waste products in the blood as a result of kidney malfunction.
Benign A mild illness or non-malignant form of a tumor. Benign tumors usually have well defined edges and tend to grow slowly.
Bilateral On both sides.
Blepharospasm 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.
Bloat Filling of the stomach with air.
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.
Borborygmus The sound of gas moving through the intestine; bowel sounds.
Bradycardia An abnormal slowing of the heart rate.
Bronchospasm A condition in which the muscles surrounding the air passages to the lungs contract, narrowing the passages.
Calculus (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.
Carcinoma A malignant cancer that arises from the epithelial tissues of the body such as the skin, intestinal tract, and bladder.
Cardiac Related to the heart.
Castration 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.
Cataract A cloudiness of the lens of the eye, reducing vision and giving the eye a pearly appearance.
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.
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.'
Cholangiohepatitis Inflammation of the gall bladder, bile ducts, and liver.
Cholangitis Inflammation of a bile duct; see cholecystitis.
Cholecystitis Inflammation of the gallbladder; see cholangitis.
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.
Cirrhosis A liver disease caused by the replacement of damaged cells with connective tissue; severe scarring can eventually cause liver failure.
Coagulopathy A condition affecting the blood's ability to form a clot.
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.
Cold-Blooded Having a body temperature that is not regulated internally, but varies with the environmental temperature. Turtles, lizards, and snakes are cold-blooded.
Colitis An infection or inflammation of the colon.
Coma Being in a state of unconsciousness.
Conception The onset of pregnancy, when the fertilized egg attaches to the uterus.
Conjunctivitis An inflammation of the lining of the eyelids; may cause pain, redness, itching, and a discharge.
Constipation A condition in which the movement of food through the digestive system is longer than normal; often results in hard, dry stool.
Contusion An injury to underlying tissues without breaking the skin; a bruise.
Coprophagia Eating dung or fecal matter; normal behavior in some animals, such as rabbits.
Cushing’s 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.
Cyanosis Bluish or grayish color to the skin and gums which occurs when the animal has insufficient oxygen.
Cystitis Inflammation of the urinary bladder.
Defecation The elimination of feces from the rectum.
Dehydration A condition in which the body loses more water than it takes in.
Dermatitis An inflammation of the skin.
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.
Diarrhea 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.
Diestrus The stage of the estrus cycle which occurs after the animal goes out of heat (also called Diestrous).
Dilated Cardiomyopathy A heart condition in which the heart enlarges, but the heart muscle becomes thinner.
Distemper 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.
Diuresis Increase in urine production.
Dry Eye Keratoconjunctivitis sicca (KCS) is the technical term for a condition also known as 'dry eye.' It occurs because of inadequate tear production. Symptoms include a thick, yellowish discharge from the eye.
Dysecdysis Abnormal shedding of the skin in reptiles.
Dysphagia Difficulty swallowing.
Dysplasia An abnormal tissue development, common in the bones of the canine.
Dyspnea Shortness of breath.
Dystocia Difficult birth.
Dystrophy Disorder caused by incorrect nutrition.
Dysuria Difficult or painful urination.
Ear Mites Small parasitic insects that live in the ear canal of an animal, and that are able to survive outside the ear for only very short periods of time.
Ecdysis Shedding of the external layers of the skin in reptiles.
Edema A condition in which the tissues of the body contain too much body fluid. The fluid accumulation may cause swelling in the affected area.
Emaciation The severe loss of body weight; body weight is generally less than 50% of that in a normal animal.
Encephalitis Inflammation of the brain; often caused by a virus.
Encephalopathy Any degenerative disease of the brain. Causes include liver disease resulting in the buildup of toxic by-products of metabolism, heavy metal (e.g., lead) poisoning, and loss of blood supply.
Enteritis An inflammation of the intestines.
Eosinophilia A condition in which there are more than the usual number of eosinophils in the circulating blood.
Epiphora An overflow of tears upon the cheeks due to a blockage or narrowing of the tear ducts.
Epistaxis Bleeding from the nose.
Erosion A shallow defect in the skin. When healed, it will not cause a scar.
Erythema Redness of the skin caused by blood clogging in small blood vessels.
Esophageal Reflux A condition in which stomach contents move backward into the esophagus, i.e., heartburn.
Estrus The time when a female animal is fertile and receptive to the male. Also known as a heat period.
Exophthalmos The abnormal outward protrusion (bulging) of the eye.
Extensor Rigidity A condition in which muscles contract and tend to straighten the limb, prevent it from relaxing.
Flatulence Increased stomach or intestinal gas.
FLUTD Feline lower urinary tract disease; a condition in cats characterized by blood in the urine, urination outside of the litter box, and straining to urinate. The name for this condition was previously called feline urological syndrome (FUS).
Fracture A break in the bone; generally caused by trauma, twisting, or weakened bone structure due to disease.
FUS Feline urological syndrome; a condition in cats characterized by blood in the urine, urination outside of the litter box, and straining to urinate. The name for this condition is now called feline lower urinary tract disease (FLUTD).
Gastritis Inflammation of the stomach.
Gingivitis Inflammation of the gums.
Glaucoma Increased pressure within the eye caused by an accumulation of fluids; can lead to blindness if left untreated.
Glucosuria Glucose in the urine. (Also called glycosuria.)
Granuloma The formation of a nodule as a result of inflammation.
Head Pressing Pressing the head against a wall or other hard object.
Heart Block A condition in which the electrical impulses of the heart are not properly conducted from the atria (chambers which receive the blood) to the ventricles (chambers which pump the blood).
Hemangiosarcoma A malignant tumor of the blood vessels, usually occurring in the skin, liver, spleen, right atrium of the heart, and muscle; also called angiosarcoma.
Hematoma A mass of blood within the tissues. Generally, the result of trauma to the blood vessels or abnormal blood clotting.
Hematuria A condition of blood in the urine.
Hemoptysis Blood in the sputum.
Hemorrhage To bleed excessively; may be the result of injury or blood clotting abnormalities.
Hepatic Fibrosis Scarring of the liver Hepatitis An inflammation or infection of the liver.
Hepatomegaly Enlargement of the liver.
Hernia The protrusion of an organ through an abnormal opening.
Humoral Immunity The immunity that is the result of antibody production by B cells. Compare with 'cell-mediated immunity.'
Hydrocephalus A condition of fluid accumulation in the ventricles (spaces) of the brain; the swelling generally creates pressure on the brain tissues and can cause severe damage if not treated properly.
Hypercalcemia An increased level of calcium in the blood.
Hyperesthesia Abnormal sensitivity to touch, pain, or other sensory stimuli.
Hyperglycemia Higher than normal blood glucose level.
Hyperkalemia Increased level of potassium in the blood.
Hyperphosphatemia Elevated blood phosphate levels.
Hyperpigmentation An increased dark color in the skin caused by the pigment 'melanin.'
Hyperplasia An increase of the number of cells within an organ.
Hyperplastic Abnormal increase in the amount of tissue, e.g., a hyperplastic ear would have increased numbers of cells in the ear canal, sometimes to the point of closing off the ear canal. In prostatic hyperplasia, the prostate enlarges due to an increased number of normal, not cancerous, cells.
Hyperreactive Producing an exaggerated, or greater than normal response to a stimulus.
Hypersensitive A type of allergic condition in which the body overreacts to a certain agent such as a bee sting or medication.
Hypertension Blood pressure above normal.
Hyperthermia An increase in body temperature above normal.
Hyperthyroidism A condition, more commonly seen in cats, in which the thyroid gland produces too much thyroid hormone.
Hypertrophy An increase in the size of a tissue or organ due to the enlargement of existing cells.
Hyperventilate An increase in the rate and/or depth of respiration such that the body loses too much carbon dioxide.
Hypoglycemia Lower than normal blood glucose level.
Hypokalemia Lower than normal level of potassium in the blood.
Hypoplasia Inadequate or defective development of tissue.
Hypotension Blood pressure below normal.
Hypothermia A decrease in body temperature below normal.
Hypothyroidism A condition, more common in dogs, in which the thyroid gland does not produce enough thyroid hormone.
Hypovitaminosis A A condition in which the body suffers from a deficiency in Vitamin A.
Hypoxia Low oxygen level in blood and tissues.
Iatrogenic A condition resulting from the action of the doctor; e.g., an allergic reaction resulting from administration of an injection by a veterinarian.
Icterus Commonly referred to as jaundice. A yellowing of the tissues, usually as a result of abnormal liver function.
IDDM Insulin dependent diabetes mellitus (IDDM): A form of diabetes in which so little insulin is produced that supplemental insulin must be given for the animal to live. Also called Type I diabetes mellitus.
Ileus A condition in which there is an absence of muscular contractions of the intestine which normally move the food through the system; can result in an intestinal obstruction.
Immune-Mediated Immune-mediated reaction or disease: A condition or disease caused by abnormal activity of the immune system in which the body's immune system either over-reacts (e.g., immune-mediated contact dermatitis) or starts attacking the body itself (e.g., autoimmune hemolytic anemia). See also autoimmune.
Immunodeficiency Reduced function of the immune system of an animal, making it more susceptible to infectious disease. Can be an inherited defect or caused by drugs, radiation, or viruses.
Incontinence The inability to control the excretion of wastes; generally used to describe the inability to control urination.
Infection The invasion and replication of microorganisms in tissues of the body; generally causes disease or local inflammation.
Inflammation A condition in which tissue reacts to injury and undergoes changes during the healing process. As an example, a toe with a sliver of wood in it would be inflamed and show the signs of inflammation which include redness, increased temperature, pain, swelling, and a loss of or disordered function. The toe is swollen, red, hot, painful, and the animal is reluctant to walk on that toe.
Inherited A trait passed from one generation to the next in the genes from each parent.
Innate A permanent characteristic that is present because of the genetic make-up of the animal.
Insulin Resistance A condition in which the blood glucose level remains higher than it should at an insulin dosage of 2 units/pound of body weight per day in cats.
Insulinoma Insulin-producing tumor of the pancreas; the increased production and blood level of insulin resulting from these tumors can cause low blood sugar (hypoglycemia).
Interstitial Between parts or within the spaces of tissue.
Intestine The part of the digestive system extending from the stomach to the rectum; includes both the small and large intestines and functions in the absorption of water and nutrients; also called bowel or gut.
Intussusception A condition in which one part of the intestine 'telescopes' into another.
Jaundice The condition in which there is a buildup of waste products in the body called bilirubin. Bilirubin is yellow in color, therefore, an animal with jaundice will have yellow gums, skin (often seen on the inside flap of the ear), and a yellowish cast to the 'whites' of the eyes. It can occur if a large number of red blood cells are destroyed, the liver is not functioning normally, or the bile ducts are blocked.
KCS Keratoconjunctivitis sicca is the technical term for a condition also known as 'dry eye.' It occurs because of inadequate tear production. Symptoms include a thick, yellowish discharge from the eye.
Keratitis Inflammation of the cornea of the eye; may be caused by infection, trauma, or an allergic reaction.
Keratoconjunctivitis Sicca Keratoconjunctivitis sicca (KCS) is the technical term for a condition also known as 'dry eye'. It occurs because of inadequate tear production. Symptoms include a thick, yellowish discharge from the eye.
Ketoacidosis A life-threatening condition in which ketones, which result from the breakdown of fat for energy, accumulate in the bloodstream and the pH of the blood decreases.
Lactating Producing milk.
Latent A dormant stage of disease; the patient is infected with an organism, but is not yet ill.
Leptospirosis A bacterial disease that may be exposed to animals through contaminated water or exposure to urine from an infected animal. The Leptospira bacteria may spread to many types of tissues, but tend to be found in the kidneys. Symptoms include fever, joint or muscle pain, decreased appetite, weakness, vomiting and diarrhea, frequent urination which may be followed by lack of urination, discharge from nose and eyes and yellowing of the gums, membranes around the eyes and skin.
Leukopenia A condition in which the numbers of white blood cells in the blood are lower than normal.
Lichenification Thickening and hardening of the skin.
Malabsorption syndrome Maldigestion syndrome: A condition involving the intestine in which food may not be properly digested or the nutrients not absorbed.
Malnutrition Ill health due to dietary deficiency or imbalance.
Mange Any of several skin and ear conditions caused by a variety of mites.
Mast cell Tumor A nodular growth, usually on the skin, which involves cells (mast cells) which contain large amounts of histamine and normally play a role in allergic reactions. All mast cell tumors in dogs should be considered potentially malignant.
Mastitis An infection or inflammation of the mammary glands.
Megacolon A condition in which the colon enlarges and dilates, which results in feces accumulating in the colon. Constipation then occurs. This condition is more common in cats than dogs.
Melena Darkening of the stool due to the presence of digested blood, which indicates bleeding is occurring in the stomach and/or beginning of the small intestine. The feces generally look black and tarry.
Metabolic Acidosis A condition in which the pH of the blood is too acidic because of the production of certain types of acids.
Metastasis Spread of a tumor from its original location to a remote one, by tumor cells that are carried in the blood.
Methemoglobinemia A condition of the blood in which there are large amounts of methemoglobin which is an altered hemoglobin which does not carry oxygen.
Microfilaremia The presence of microfilariae in the blood.
Myasthenia Gravis Myasthenia gravis is a neuromuscular disease in which there is a failure of the nerves' ability to stimulate and control the actions of certain muscles.
Mycosis Disease caused by a fungus such as blastomycosis, histoplasmosis, and ringworm.
Mydriasis Small pupil size.
Nephropathy Any disease or abnormal functioning of the kidney.
Neuropathy Abnormal functioning of nerves.
Neuter Sterilization by surgical removal of the testicles of a male animal or ovaries of a female animal.
NIDDM Non-insulin dependent diabetes mellitus (NIDDM): A type of diabetes mellitus in which although the blood glucose levels are higher than normal, they are not immediately life-threatening, and the animal can survive without supplemental insulin. Also called Type II diabetes.
Nodule Solid bump or lump in the skin that is over 1/3 inch in diameter.
Nystagmus Constant involuntary movement of the eye, often from side to side.
Obsessive Compulsive A behavioral condition in which a pet repeatedly performs an action out of context. It is thought that the behavior is an expression of stress, frustration and/or conflict. Certain breeds are more prone to these behaviors. The behaviors include tail-chasing, some cases of excessive barking, continual licking, and biting the air as if snapping at an invisible fly.
Osteomyelitis An inflammation and infection of the bone.
Pancreatitis Inflammation of the pancreas, a severe and sometimes life threatening disease often associated with eating fatty foods. Symptoms include vomiting and a painful abdomen.
Pannus 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 chronic superficial keratitis.
Papule Solid bump on the skin, less than 1/3 inch in diameter.
Paralysis Loss of motor function (movement) in a certain part of the body. Paralysis may be flaccid, in which muscles are weak and have little or no tone; or spastic, in which the muscles are tight.
Paresis Slight or incomplete paralysis.
Parthenogenesis A form of reproduction in which the egg develops into a new individual without fertilization by sperm. Parthenogenesis has been observed in many lower animals, including some snails and insects.
Parturition The act of giving birth.
Passive Immunity Immunity produced by providing an animal with antibodies or immunologic cells from another source, such as colostrum. Compare with 'active immunity.'
Pediculosis An infestation of lice.
Perianal Fistula A deep infection around the anus which often results in ulcers and deep draining tracts, most commonly seen in German Shepherds.
Peritonitis Inflammation of the lining of the abdomen.
Photosensitivity A condition in which the skin reacts abnormally to light, especially ultraviolet light or sunlight. It is usually caused by the interaction of light with certain chemicals in the skin such as antibiotics, other medications, hormones, or toxins.
Pica Craving to eat unnatural articles such as rocks or dirt.
Plantigrade Stance Standing and walking with the hocks on or almost touching the floor.
Plaque A build-up of bacteria, saliva, and food on the teeth. See also Tartar.
Plastron The lower hard shell-like structure which protects the abdomen of a turtle or tortoise.
Polyarthritis Arthritis which involves two or more joints.
Polydactyl The presence of extra toes.
Polydipsia Excessive thirst resulting in excessive drinking.
Polyestrous During one sexual season, continuing to come into heat if not bred. Cats are polyestrous, dogs are not.
Polyp A small growth from mucous membranes such as those lining the nasal cavity and intestinal tract.
Polyphagia Excessive ingestion of food.
Polyuria Excessive urination.
Prolapsed Rectum Because of irritation or injury, the inner part of the rectum is pushed out so that it is visible as a pink mass protruding from the anal opening.
Pulmonary Edema Fluid accumulation in the lungs.
Pulmonary Emboli Pulmonary embolism: Blood clot that travels to the blood vessels in the lung and obstructs them.
Pustule Small elevated area on the skin filled with pus.
Pyloroduodenal An obstruction in the area where the stomach and small intestine meet.
Pyoderma An infection of the skin; usually the result of a bacterial invasion.
Pyometra An infection of the uterus.
Queening In cats, the act of giving birth.
Rabies A fatal virus disease of warm blooded animals including man, that affects the brain and is spread in the saliva of infected animals. Rabid animals have a temperament change. Wild creatures become bold enough to attack human beings, and docile domestic animals may turn on their owners.
Regurgitation Expelling food from the esophagus.
Renal Insufficiency The decreased ability of the kidneys to rid the body of wastes.
Resorption In pregnancy, a condition in which the fetus dies, and instead of being aborted, the fetal tissue dissolves within the uterus and is absorbed by the mother. The mother will show no outward signs of a fetal resorption.
Respiratory Depression Decrease in the rate or depth of respiration.
Ringworm A type of fungal infection of the skin.
Scale Accumulation of loose fragments of the top layer of the skin.
Schiff-Scherrington Posture A condition, caused by a lesion in the spinal cord, in which the front legs are held rigid and straight, and the rear legs are weak or paralyzed. Sometimes, the neck may be hyperextended, with the head held up and over the back.
Sclerosis A hardening of tissue, usually the result of chronic inflammation.
Sebaceous Adenitis Inflammation of a sebaceous (oil-producing) gland. In dogs, sebaceous glands are found on the top of the tail near its base, and at the junction of mucous membranes with skin. In cats, these glands are found on the chin, lip margins, and the top of the tail.
Secondary 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 'anamnestic response.'
Separation Anxiety A behavioral condition in which the pet becomes anxious when separated from the owner. Dogs with separation anxiety tend to 'shadow' their owners, greet them exuberantly when they return after being gone, and sometimes vocalize, chew destructively, and urinate or defecate when separated from their owners.
Sepsis The presence of toxins in the blood or other tissues; the toxins are produced by bacteria or other microorganisms.
Septic A condition caused by an infection e.g., with bacteria or fungi, or toxins they produce.
Septicemia A disease affecting many organ systems due to toxins in the blood which are released by bacteria or other microorganisms. Signs include fever, pinpoint bruises on mucous membranes, and lesions in the joints, heart valves, eyes, or other organs.
Shedding Shedding (of organisms): A term used to describe the release of organisms (bacteria, protozoa, viruses) into the environment from an infected animal. The organisms may be in the stool, urine, respiratory secretions, or vaginal discharges. The 'shedding' animal may or may not be showing symptoms of disease.
Smooth Muscle The type of muscle found in the internal organs such as stomach and intestines (not the heart).
Somnolence Sleepiness, a condition of semiconsciousness approaching coma.
Somogyi Effect A condition in which the blood glucose level increases if too much insulin is given. It occurs when insulin causes the blood glucose level to go so low it stimulates the production of other hormones in the body such as epinephrine, which promote the breakdown of glycogen (the chemical compound which the body uses to store glucose) and increases the blood glucose level above normal. It is also called rebound hyperglycemia or insulin-induced hyperglycemia.
Spay Sterilization by surgical removal of the ovaries and uterus of a female animal.
Stasis In the gastrointestinal tract, a condition in which the food does not move through normally, but remains in one section, e.g., food does not pass from the stomach into the intestine.
Status Epilepticus A condition in which the animal exhibits one severe (Grand Mal) seizure right after another, with no time to recover in-between.
Stenosis The narrowing of an organ of passage such as a blood vessel or intestine.
Stress-Induced Hyperglycemia A condition in cats in which the blood glucose level becomes abnormally high when the animal is stressed, e.g., in the veterinarian's office.
Stricture The narrowing of an organ of passage such as a blood vessel or intestine.
Subluxation A partial dislocation of a joint in which the bones become out of alignment, but the joint itself is still intact.
Supraventricular Tachycardia A condition in which the heart beats very rapidly because of signals coming from the atria (chambers of the heart that receive the blood) or near the junction of the atria with the ventricles (the chambers of the heart that pump the blood to the body or lungs).
Syncope The temporary loss of consciousness; fainting.
Tartar A build-up of bacteria, saliva, and food on the teeth which becomes mineralized, forming a hard coating and eventually causing gum disease and tooth loss. See also 'Plaque.'
Thrombocytopenia A lower than normal number of platelets in the blood. Platelets, which are actually fragments of specific types of cells, are necessary for blood to clot. Signs of thrombocytopenia include bruising and bleeding from the nose, into the gastrointestinal tract, etc.
Tissue A group of specialized cells that together perform a particular function, e.g., muscle tissue, nerve tissue, bone.
Torsion The twisting of an organ.
Toxemia A condition in which toxins move into the bloodstream.
Tracheobronchitis Inflammation of the trachea and bronchi.
Tricyclic Antidepressant A class of antidepressants which work by decreasing the amount of certain chemical transmitters taken up by specific nerve cells. The tricyclic antidepressants include clomipramine, amitriptyline, and nortriptyline and are often used to treat behavioral problems in small animals.
Tumor Abnormal growth or swelling; term often used to designate cancer.
Type I Diabetes A form of diabetes in which so little insulin is produced that supplemental insulin must be given for the animal to live. Also called insulin dependent diabetes mellitus (IDDM).
Type II Diabetes A type of diabetes mellitus in which although the blood glucose levels are higher than normal, they are not immediately life-threatening, and the animal can survive without supplemental insulin. Also called non-insulin dependent diabetes mellitus (NIDDM).
Ulcer A lesion in which the tissue surface is eroded away.
Urinary Incontinence A phrase used to describe the inability to control urination.
Urinary Obstruction A blockage in the urinary system, most often occurring in the urethra, the tube that leads from the urinary bladder to the outside of the body.
Urinary Retention A condition in which the urinary bladder does not rid itself of all urine it contains during the process of urination.
Urticaria Hives; development of small swellings which may itch; usually caused by an allergic reaction.
Uveitis Inflammation of the eye.
Vaccine Failure A term often used to describe a condition in which an animal who was vaccinated against a disease still gets the disease. In truth, there is usually nothing wrong with the vaccine, but for some reason, the animal's immune system did not adequately react to it.
Vasculitis Inflammation of blood vessels.
Vasoconstriction A decrease in the diameter of blood vessels.
Ventricular Arrhythmia A heart condition in which the heart beats irregularly and/or at an abnormal rate because of signals coming from the ventricles (chambers of the heart that pump the blood).
Virus The smallest form of life, invisible with an ordinary microscope. An infectious unit that enters and uses cells of plants or animals for replication. Some viruses cause disease in animals or plants.
Volvulus Twisting of the stomach or intestine, which often has the effect of cutting off the blood supply to it.
Wart Benign growth caused by a virus.
Wasting Loss of muscle mass due to decreased food intake or increased metabolic rate.
Whelping In dogs, the act of giving birth.