Horse Health Glossary

Not sure what that veterinary word means? Look it up below!

Reprinted with permission from the University of California, Davis, The Book of Horses edited by Mordecai Siegal.

CACHEXIA:
Seriously poor health; malnutrition and wasting.
CAESAREAN SECTION:
Delivery of a fetus by surgically removing it from the uterus.
CALCANEUS:
Heel bone.
CALCIFICATION CENTERS:
Areas of bone deposit and change within bone tissue.
CALCITONIN:
A calcium-regulating hormone produced by the thyroid gland.
CALCIUM CHANNEL BLOCKERS:
Drugs useful in treating tachycardias (abnormally rapid heart rates).
CALCULOGENIC:
Stone-forming.
CALCULUS (PLURAL: CALCULI):
Dental tartar, the mineralized concretions of salivary calcium and phosphorus salts and tooth-surface plaque; also, a urinary stone.
CALORIE:
Unit defined as the amount of energy needed to raise the temperature of 1 gram of water 1 degree Celsius (centigrade). However, the larger kilocalorie is usually referred to as a "calorie" in the nonscientific community.
CANCELLOUS BONE:
Bone tissue having a spongy or latticelike internal structure; an example is the bone marrow.
CANCER:
The general term for any malignant tumor.
CANDIDIASIS:
A relatively uncommon infection of skin and mucous membranes of the oral cavity, respiratory tract, and genital area of horses, caused by yeast of the genus Candida.
CANKER:
Chronic overgrowth of the horn-producing tissues of the foot, occurring most commonly in horses housed under unsanitary conditions.
CANNON BONE:
The third metacarpal bone, above the fetlock joint.
CANNON KERATOSIS:
Seborrhea affecting the front surface of the rear cannon bone.
CANNULA:
A tube inserted into a duct or body cavity, for the purpose either of infusing or removing fluid.
CANTHARIDIN:
The toxin in blister beetles responsible for blister beetle poisoning in horses.
CAPILLARIES:
The smallest blood vessels. They permeate the tissues, serving as microscopic extensions of arterioles and venules; through their semipermeable walls, fluids, nutrients, and waste gases are exchanged between the blood and the tissues.
CAPPED HOCK:
Traumatic bursitis over the point of the hock, usually caused by the horse's kicking a solid structure.
CAPS:
Remnants of deciduous premolar teeth that are left behind when the permanent premolars erupt.
CARBUNCLE:
A deep-seated skin infection containing many pockets of pus.
CARCINOGEN:
Any cancer-causing substance, such as asbestos, nickel, alcohol, or tobacco.
CARCINOMA:
A cancer (malignant tumor) of epithelial cells.
CARDIAC:
Pertaining to the heart.
CARDIAC ARREST:
Cessation of the heartbeat.
CARDIAC CATHETERIZATION:
The passing of a catheter through a peripheral blood vessel and inside the heart, either for diagnostic or therapeutic purposes.
CARDIAC INSUFFICIENCY:
Heart failure.
CARDIAC MUSCLE:
Specialized type of muscle found only in the heart.
CARDIAC TAMPONADE:
Acute compression of the heart, caused by filling of the pericardial sac with fluid or blood.
CARDIAC ULTRASOUND:
Examination of the heart by means of ultrasonic sound waves, for the purpose of disease diagnosis; also known as echocardiography.
CARDIOGENIC SHOCK:
Shock caused by a diseased heart that has become so dysfunctional that it can no longer pump sufficient blood to the body.
CARDIOMYOPATHY:
Enlargement of the heart, caused either by a thickening or thinning of the heart muscle.
CARDIOPULMONARY BYPASS:
Open-heart surgery wherein a heart-lung machine oxygenates and pumps blood while the heart is stopped.
CARDIOVASCULAR SYSTEM:
The heart and blood vessels of the body.
CARNIVORES:
Meat eaters.
CARPAL CANAL SYNDROME:
Annular ligament constriction on the back side of the carpus, causing lameness.
CARTILAGE:
Specialized connective tissue especially important in bone growth and the formation of joints.
CASLICK'S OPERATION:
Surgical procedure to decrease the aspiration of air and contaminants into the female reproductive tract.
CASTRATION:
Surgical removal of the testes; sterilization of the male.
CASTS:
Solid, tubular deposits in the urine, usually cast off from the walls of kidney tubules.
CATABOLISM:
The body's breakdown of complex molecules, such as protein and fat, to simpler compounds.
CATARACT:
Lens opacity in the eye, affecting vision.
CATECHOLAMINES:
Compounds secreted by the adrenal medulla, the most notable of which is epinephrine (adrenaline).
CATHARTICS:
Drugs to induce evacuation of the bowel.
CATHETER:
A flexible tubular instrument for insertion into a blood vessel or body cavity.
CAUDA EQUINA:
The nerve roots at the termination of the spinal cord.
CAUDAL:
To the rear of; toward the tail.
CECUM:
The first segment of the large intestine, consisting of a large dilated pouch.
CELL:
The most basic functioning unit of living organisms, composed of a nucleus, cytoplasm, organelles, and other constituents. Cells are the fundamental building blocks of tissues and in their nuclei contain all the genetic information necessary for the growth and differentiation of a complete organism.
CELLULAR (CELL-MEDIATED) IMMUNE RESPONSE:
The mounting of a cytotoxic T cell/macrophage/natural killer (NK) cell immune response to an antigen.
CELLULAR DIFFERENTIATION:
The process by which cells mature into specialized, fully functioning units.
CELLULITIS:
Diffuse inflammation resulting from (usually bacterial) infection of deep connective tissue, sometimes forming an abscess.
CEMENTUM:
Specialized type of connective tissue that covers the tooth roots.
CENTRAL NERVOUS SYSTEM (CNS):
The brain and spinal cord.
CENTRIFUGE:
To spin in order to separate the light and heavier particulates in a fluid sample; a machine for performing this procedure.
CERCARIA:
Tadpolelike larval form of flukes that arises from the redia stage.
CEREBELLAR ABIOTROPHY:
Inherited disorder seen in some Arabian family lines, characterized by a progressive loss of neurons in the cerebellum.
CEREBELLAR HYPOPLASIA:
Underdevelopment of the cerebellum, manifested clinically by incoordination.
CEREBELLUM:
Portion of the brain concerned with motor function, balance, and the coordination of movement.
CEREBROSPINAL FLUID (CSF):
Fluid bathing the surfaces of the brain and spinal cord.
CEREBRUM:
Portion of the brain concerned with conscious thought, perceptions, and learned skills.
CERUMINOUS GLANDS:
Glands that produce the waxy coating of the ear canal.
CERVICAL:
Pertaining to the neck.
CERVICAL SPONDYLOSIS:
Degenerative and proliferative disease of the neck vertebrae.
CERVIX:
Oval-shaped mass in the female reproductive tract whose opening connects the uterus with the vagina.
CESTOCIDAL:
Able to kill tapeworms.
CESTODES:
Tapeworms; internal parasites having a head unit (scolex) and numerous body segments (proglottids).
CHEEKTEETH:
General term for the premolar and molar teeth.
CHEMOSIS:
Excessive swelling of the conjunctiva (membranes covering the inner surface of the eyelids).
CHOKE:
Physical obstruction of the esophagus.
CHOLINE:
A B vitamin important for proper function of the nervous system and for preventing fat deposition in the liver.
CHONDROIDS:
Pus in the guttural pouch that, over time, has becomed thickened into variously sized, cheesy concretions.
CHONDROSARCOMA:
A malignant tumor of cartilage.
CHORIORETINITIS:
Inflammation of the choroid and retina of the eye.
CHOROID:
Thin, pigmented middle layer of the eye containing nerves and blood vessels; it supplies blood to the retina.
CHROMOSOMES:
The very large and complex molecules of DNA that occur in the nucleus of every cell and that carry the genetic information needed to make every protein in the body.
CHRONIC:
Long-term; of lengthy duration; persisting over a long period.
CHRONIC CARRIER STATE:
Situation in which an animal or human being maintains (carries) an infectious disease agent for a prolonged period of time.
CHRONIC INTERSTITIAL NEPHRITIS:
Chronic, progressive destruction of the kidneys, marked by a reduction in kidney size and scarring of kidney tissue.
CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD):
Term referring to a number of conditions leading to chronic or recurrent obstruction of airflow within the lung; also called heaves or broken wind.
CHRONIC PHARYNGEAL LYMPHOID HYPERPLASIA (CPLH):
An abnormal increase in size of the lymphocyte-rich tissues lining the pharynx, analogous to tonsillitis of children; also referred to as chronic pharyngitis or follicular pharyngitis.
CICATRIZATION:
Scar-tissue formation.
CILIA (SINGULAR: CILIUM):
Minute, hairlike cellular processes lining much of the respiratory tract; their rhythmic beating movements, in concert with an overlying layer of mucus, effect removal of debris and other foreign material from the airways.
CILIARY BODY:
The circular muscle located directly behind the iris of the eye.
CIRRHOSIS:
Liver disease characterized by replacement of functioning liver cells by scar tissue.
CLASSICAL CONDITIONING:
The association between a stimulus and a response.
CLEFT PALATE:
Birth defect characterized by an abnormal connection between the oral cavity and the nasal cavity; as a result, small amounts of milk often may be seen dripping from the nostrils when the foal suckles.
CLITORIS:
Small mound of erectile tissue in the female reproductive tract; the female analog of the male penis.
CLUB FOOT:
In horses, a flexural deformity of the coffin joint resulting in a raised heel; not to be confused with the club foot deformity of human beings.
COAGULATION:
Blood clotting.
COBALAMIN:
Cobalt-containing component of vitamin B12.
COCCIDIOIDOMYCOSIS:
The main systemic fungal infection of importance in horses in the United States, characterized by chronic weight loss, persistent coughing, musculoskeletal and/or abdominal pain, intermittent fever, and superficial abscesses; caused by Coccidioides immitis.
COCHLEA:
Curled bone in the inner ear which contains the organ of Corti, the actual organ of hearing.
CODOMINANT ALLELES:
Genes wherein both members of an allelic pair are fully expressed.
COFFIN BONE:
The distal phalanx or toe of the forelimb, incorporated within the hoof.
COGGINS TEST:
Test for detection of antibody to equine infectious anemia (EIA) virus.
COITUS:
Sexual intercourse.
COLIC:
Acute abdominal pain.
COLITIS:
Inflammation of the large bowel (colon); contrasts with enteritis (inflammation of the small intestine).
COLLAGEN:
Protein constituent of connective tissue.
COLOBOMA:
A defect of any tissue of the eye.
COLON:
The portion of the large intestine connecting the cecum (lowermost portion of the small intestine) with the rectum.
COLONOSCOPY:
Endoscopic examination of the colon.
COLOR FLOW DOPPLER ECHOCARDIOGRAPHY:
Technique using sound waves to examine the direction and velocity of blood flow within the heart and great vessels, allowing the cardiologist to observe directly the regions of abnormal blood flow that develop in association with most common cardiac abnormalities.
COLOSTRUM ("FIRST MILK"):
Milk produced by the mare during the first day or two after the birth of her foal; it is high in protein and protective antibodies (maternal immunity).
COMA:
Unconsciousness from which one cannot be aroused.
COMATOSE:
Unconscious and unable to be aroused.
COMMINUTED FRACTURE:
Fracture in which the affected bone is broken or crushed into small fragments.
COMMISSURE OF THE LIPS:
The corner of the mouth.
COMPLEMENT SYSTEM:
A specialized series of blood proteins whose major role is to disrupt the surface structure of microbes and altered body cells, resulting in their destruction.
COMPLETE BLOOD COUNT (CBC):
Blood analysis containing an enumeration of the number of red and white blood cells per unit of blood volume, the proportions of the different white blood cell types, and the amount of hemoglobin present.
COMPOUND FRACTURE:
Fracture that breaks through the skin; open fracture.
COMPUTERIZED AXIAL TOMOGRAPHY (CAT SCAN):
Highly specialized diagnostic X-ray technique that produces cross-sectional images of the inside of the body.
CONCENTRATES:
Rich sources of individual nutrients that are used to enhance the quality of the diet.
CONCEPTUS:
Embryo or fetus plus the accompanying extraembryonic membranes.
CONCUSSION:
A violent blow to the head, usually resulting in the loss of consciousness.
CONES:
Photoreceptor cells in the retina of the eye that are responsible for color vision and visual acuity.
CONFORMATION:
The overall physical appearance of a horse, reflecting the arrangement of muscle, bone, and other body tissues.
CONGENITAL:
Present at birth.
CONGENITAL HYPOTRICHOSIS:
Hairlessness.
CONGENITAL STATIONARY NIGHT BLINDNESS:
An hereditary abnormality of vision affecting Appaloosas.
CONGENITAL TESTICULAR HYPOPLASIA:
Underdevelopment of the testicles.
CONGESTIVE HEART FAILURE:
Syndrome caused by the inadequate pumping of blood by the heart.
CONIDIOBOLOMYCOSIS:
A form of phycomycosis caused by Conidiobolus coronatus, characterized by a thick nasal discharge, coughing, respiratory difficulty, and halitosis (bad breath).
CONJUNCTIVA:
Mucous membrane lining the eyelids and covering the white surface (sclera) of the eyball.
CONJUNCTIVITIS:
Inflammation of the conjunctiva.
CONNECTIVE TISSUE:
A general term encompassing the different types of supportive tissues that hold together many body structures.
CONSTITUTIONAL SIGNS:
Generalized clinical signs, such as inappetence, lethargy, weight loss.
CONTAGIOUS EQUINE METRITIS:
Highly contagious disease characterized by inflammation of the female genital tract and production of a thin, profuse, grayish-white discharge from the vulva; caused by a bacterium, Taylorella equigenitallium.
CONTINUOUS HEART MURMUR:
A murmur that is present during both contraction and relaxation of heart muscle.
CONTRACTED TENDONS:
A developmental orthopedic disease of foals, associated with rapid growth rates and high planes of nutrition.
CONTRALATERAL:
On the opposite side.
CONTUSION:
A bruise.
CONVULSIONS:
Seizures.
COOMBS' TEST:
An immunologic procedure for the detection of autoantibody attached to red blood cells; also called an antiglobulin test; important in disease diagnosis as well as in cross-matching blood samples for transfusion purposes.
COPROPHAGY:
The eating of feces.
COR PULMONALE:
Disease of the right side of the heart caused by increased pressure within the pulmonary artery.
CORACIDIUM:
Free-swimming larval form of pseudophyllidean tapeworms.
CORE BIOPSY:
Biopsy obtained from an awake patient using local anesthesia and a specialized small-bore biopsy needle.
CORNEA:
The transparent outer coat of the eye.
CORNIFIED:
Converted into hardened tissue; keratinized.
CORNS:
Chronic lesions found in the sole of the foot, at the angle formed by the wall and the bar of the sole.
CORNSTALK DISEASE:
Common name for leukoencephalomalacia.
CORONARY BAND:
Ring of vascular tissue along the upper edge of the hoof wall from which the horn of the hoof grows.
CORONITIS:
Inflammation of the coronary band.
CORPORA NIGRA:
A row of dark protuberances normally present along the upper border of the equine iris; also called granula iridica.
CORPUS LUTEUM (PLURAL: CORPORA LUTEA):
Ovarian follicle after discharge of the ovum (egg); it secretes the hormone progesterone.
CORTEX:
Outer layer of an organ (kidney, adrenal gland, brain) or hair shaft; contrasted with medulla.
CORTICOSTEROIDS:
Steroid hormones (cortisol, corticosterone, etc.) produced by the cortex of the adrenal gland
CORTICOSTERONE:
A corticosteroid hormone.
CORTISOL:
A corticosteroid hormone.
CORTISONE:
A corticosteroid hormone (a precursor of cortisol) found in small quantities in the adrenal cortex.
CRANIAL:
Toward the head; pertaining to the head.
CRANIAL NERVES:
Nerves originating largely in the brain stem that control the facial muscles and certain specialized activities of the head (sight, smell, hearing).
CREATINE KINASE (CK):
A muscle-specific enzyme found in serum; determination of CK levels represents a useful tool for the diagnosis of muscle disorders.
CREATININE:
Nitrogen-containing compound generated from the breakdown of ingested proteins.
CREEP FEED:
Feed provided in a separate area where the foal can eat without interference from the mare.
CREMASTER MUSCLE:
Muscle that suspends the testicle.
CRIBBING:
A stable vice in which the horse places its upper teeth on the edge of a feeder or fence, arches its neck, inhales, and often produces a grunt or belching sound.
CROSS-MATCH:
Procedure by which blood samples from donor and recipient are tested before blood transfusion, in order to determine compatibility.
CROSS-TIES:
Fixed lines attached to each side of the halter.
CROUP:
Hindquarters; area between the hips and the point of the buttocks.
CROWN:
The portion of a tooth that lies above the gum line.
CRYOGEN:
Any substance, such as liquid nitrogen, used to produce extreme cold during cryosurgery.
CRYOSURGERY:
A procedure by which local application of intense cold (freezing) is used to destroy unwanted tissue.
CRYPTORCHIDISM:
Developmental defect wherein one or both of the testicles has not descended into the scrotum.
CRYPTOSPORIDIOSIS:
Diarrheal disease of debilitated or immunodeficient foals, caused by a protozoan, Cryptosporidium parvum.
CULICOIDES HYPERSENSITIVITY:
Allergic skin disease caused by the bites of midges of the genus Culicoides; also known as Queensland itch and sweet itch.
CUNEAN BURSITIS:
Inflammation of the cunean bursa underneath the cunean tendon, which travels over the front and inside of the hock.
CURB:
Inflammation and thickening of the plantar ligament (the ligament that courses along the back of the calcaneus bone in the hock).
CUSHING'S DISEASE:
Hyperactivity of the adrenal cortex, representing the most common endocrine disorder of horses.
CUSPS:
The sharp points of the tooth crown.
CUTANEOUS:
Pertaining to the skin.
CUTANEOUS HABRONEMIASIS:
A skin disease of horses caused by stomach worms (Habronema spp.); also called summer sores.
CUTANEOUS HORNS:
Projections of hardened skin.
CUTANEOUS ONCHOCERCIASIS:
Skin disease caused by Onchocerca cervicalis, a threadworm that lives in the nuchal ligament of the neck.
CUTICLE:
The outermost layer of a hair shaft; also, the thick, noncellular covering on the surface of a roundworm (nematode) parasite.
CYANOCOBALAMIN:
Vitamin B12.
CYANOSIS:
A bluish discoloration of the skin and mucous membranes, resulting ultimately from a deficiency of oxygen in the blood.
CYST:
Simple, saclike cavity that can develop in any of a number of different body tissues; it usually contains fluid or a semisolid, cheesy or doughy material.
CYSTADENOMA:
A benign tumor of cystic and glandular structures.
CYSTITIS:
Inflammation of the urinary bladder, often occurring secondary to diseases causing incomplete emptying of the bladder.
CYTOKINES:
"Messenger molecules" by which cells of the immune system signal and instruct one another; the interferons and the interleukins are examples.
CYTOLOGIC EXAMINATION, CYTOLOGY:
The microscopic examination of cells obtained by scraping, aspiration, or biopsy, for the purpose of disease diagnosis.
CYTOPLASM:
Cell protoplasm; the fluid and particulates within a cell, exclusive of the cell nucleus.
CYTOTOXIC:
Harmful to cells.

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