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Veterinary Medical Terminology

Courtesy of Nanette Walker Smith, RVT, CVT and Elizabeth Warren, RVT

All veterinary hospitals should have a good veterinary medical dictionary accessible at all times. We recommend Saunders Comprehensive Veterinary Dictionary, second ed. by Blood and Saunders.

Basic word structure: Most medical terms can be deciphered by breaking them down to their roots: Prefix – word beginning, may completely change the meaning of the word Combining vowel – links root words to root words or suffixes (usually “o”) Root word – foundation of the word, may change to a combining form to link words Suffix – word ending, refers back to the root

The most common word structures seen in veterinary practice are listed in the charts below:

PrefixMeaningExampleLiteral TranslationActual Definition
a-, ab-, absNo, notAgalactiaCondition of no milkPartial or complete absence of milk flow in the absence of mammary gland disease
Ad-Toward, nearAdductTo draw toward the medianMovement towards the median or central line
Amb-, ambi-BothAmbidextrousBoth rightHaving the ability to work effectively with either hand
Amphi-On both sidesAmphiarthrosisJoined on both sidesJoint which surfaces are connected by fibrocartilage (allows very little movement)
An-No, notAnemiaWithout bloodDecreased number of red blood cells (erythrocytes) or the amount of hemoglobin in the erythrocytes
Ant-, anti-AgainstAntibioticAgainst lifeDestructive of life
Auto-SelfAutonomicPertaining to ones nerves(Neurologically) – not subject to voluntary control
Ana-Up, apartAnatomyProcess of cutting apartThe science dealing with the form and structure of living organisms
Bili-Pertaining to bileBiliaryPertaining to the bilePertaining to the bile, bile ducts, or gall bladder
Brady-SlowBradycardicSlow heartA slow heart rhythm
Broncho-Relating to bronchiBronchioleSmall bronchiThe very small branches of the bronchi
Cardi-, cardio-Relating to the heartCardiacPertaining to the heartPertaining to the heart
Cervico-Relating to the neckCervicalPertaining to the cervical regionPertaining to the cervical region
CircaAboutCircadianAbout the dayA daily rhythm or daily occurrence
CircumAroundCircumferenceAround the outsideMeasurement around the outside of a structure
Co-Work togetherCoagulantWork together to form clotTo cause a clot
Con-Together withConcussionTogether with blowViolent jar or shock that results in severe injury
Contra-Against, proposedContralateralAgainst the sidePertaining to, situated on, or affecting the opposite side
Di-TwiceDiarticularTwo jointsPertaining to two joints
Dia-Through, completeDiagnoseKnowledge of a conditionTo identify or recognize a disease
Dialy-To separateDialysisTo separate break apartProcess of separating components of a fluid and maintain viability
En-InwardEncephalicIn the headPertaining to the brain; within the skull
Endo-Within, innerEndocrineSecrete withinPertaining to internal secretions
Epi-AboveEpidermisPertaining to the skin aboveThe outer layer of skin
Ex-OutExciseTo cut outTo remove by cutting
Exo-Outside of, outwardExogenousPertaining to outward productionOriginating outside or caused by factors outside the organism
Extra-Outside of; in addition toExtra-labelOutside of the labelUse of a drug in a way or for a purpose not specified on the label
Fibro-Relating to fibersFibrosarcomaFiber cancerSarcoma made of fibrous tissue
Gaster-, gastr-, gastro-Pertaining to the stomachGastrotomyCut in the stomachSurgical incision into the stomach
Hemi-HalfHemilaminectomyRemoval of half the laminaRemoval of a vertebral lamina on one side only
Hemo-Relating to the bloodHemogramBlood report/graphReport of the blood parameters
Hepat-, hepatico-, hepato-Pertaining to the liverHepaticPertaining to the liverPertaining to the liver
Homeo-Denoting likeness or resemblanceHomeopathyThe study of like diseasesStudy of treating disease in a sick animal with drugs capable of producing the same response in a healthy animal
Homo-Same, similarHomogeneousGenerated the sameOf uniform quality, composition or structure
Hyal-Clear, transparentHyaline Clear, transparentPertaining to a clear/transparent appearance of a cast or membrane
Hyper-Excessive, aboveHypertrophicPertaining to excessive foodIncrease in volume of a tissue or organ produced entirely by enlargement of existing cells (over nourishment)
Hypo-Below, deficientHypothyroidDeficient thyroidDeficient thyroid gland activity
Idio-Relationship to one's self or something separate and distinctIdiopathicPertaining to a disease Pertaining to a disease with an unknown origin
In-Not, in, inside, withinIngestaMaterial withinMaterial taken into the body by mouth
Infra-BelowInfraorbitalPertaining to below the eyePertaining to below the eye
Intra-WithinIntrauterineWithin the uterusWithin the uterus
Iso-Equal, alikeIsometricEqual measureEqual measure
Karyo-Relating to a cell's nucleusKaryocyteNucleated cellNucleated cell
Laryngo-Pertaining to the larynxLaryngospasmSpasm of the larynxSpasmodic closure of the larynx (seen in cats)
Medi-MiddleMediastinumMiddle of the sternumThe membranes that separate the thorax into right and left at the sternum and vertebral column
Myelo-Pertaining to the spinal cord or bone marrowMyelogramA record of the spinal cordInjection of a dye into the space around the spinal column to produce a specific image on a radiograph
Ovari-, ovario-Pertaining to the ovaryOvariohysterectomyRemoval of the ovaries and uterusSurgical removal of the ovaries and uterus
Omni-AllOmnivoreOne that eats allAnimal that eats both plants and meat (i.e. dog)
Peri-Surrounding, aroundPerivascularPertaining to around a vesselAround a vessel
Post-Behind, afterPostsurgicalAfter surgeryAfter surgery
Pre-, Pro-Before, in front of, favoringPrognathismCondition before the jawAbnormal protrusion of one or both jaws, especially the lower one
Pseudo-FalsePseudopregnancyFalse pregnancyFalse pregnancy
Re-BackRecheckCheck backRe-examination of a patient
Retro-BehindRetrogradeGoing backwardGoing backward
Semi-HalfSemicircular Half circleHalf circle
Steato-FattySteatitisFat inflammationInflammation of fatty tissue
Sub-Under, nearSubmandibularUnder the mandibleUnder the mandible
Syn-Joined togetherSynarthrosisJoint joined togetherEssentially a fused joint (skull suture)
Trans-Across, through, beyondTransplacentalAcross the placentaThrough the placenta
Un-Not, reversalUnconsciousNot consciousNot conscious


SuffixMeaningExampleLiteral TranslationActual Definition
-able, -ible, -bleThe power to bePalpableThe power to feelAble to feel something
-acPertaining toCardiacPertaining to the heartPertaining to the heart
-alPertaining toNeuralPertaining to a nerve or nervesPertaining to a nerve or nerves
-algiaPainArthralgiaPain of the jointPain in a joint
-aseForms the name of an enzymeAsparaginaseEnzymeEnzyme that catalyzes the deamination of asparagine
-blastDesignates a cell or structureMyeloblastBone marrow cellImmature cell of the bone marrow
-celeDenoting a swellingSialoceleSwelling of the salivary glandSwelling of the salivary gland
-centesisDenoting a punctureCystocentesisPuncture of a cystCommonly known as a needle aspirate of bladder contents
-cyteCellErythrocyteRed blood cellRed blood cell
-ectomyExcisionLumpectomyExcision of a lumpExcision of a lump
-emiaBlood conditionLipemiaFat in the bloodAn excess of lipids in the blood
-esthesiaDenoting sensationAnesthesiaWithout sensationWithout sensation
-gene, -genesis, -genetic, -genicDenoting production, originAngiogenesisBlood vessel originThe development of blood vessels
-gramA tracing, a markEchocardiogramEcho tracing of the heartThe record produced by sound wave examination of the heart
-graphA writing, a recordElectrocardiographRecord of electrocardiogramThe record produced by electrical tracings of the heart
-iaConditionLeukopeniaDecreased white blood cellsReduction of the number of leukocytes (white blood cells) in the blood
-iasisDenoting a condition or pathologic stateAtelectasisCondition of collapsed lungCollapsed or airless lung tissue
-icPertaining toGastricPertaining to the stomachPertaining to, affecting, or originating in the stomach
-istOne who specializes inNephrologistPerson specializing in kidneysVeterinarian specializing in the study of kidneys
-itisInflammationPancreatitisInflammation of the pancreasInflammation of the pancreas
-logyProcess of studyZoologyThe study of animalsThe biological study of animals
-oidDenoting form or resemblanceOpiodLike an opiateSynthetic narcotic that acts like an opiate
-omaTumor, massHematomaMass of bloodA localized collection of extravasated blood, usually clotted, in an organ, space, or tissue
-opsyProcess of viewingNecropsyViewing of a deceased bodyExamination of a body after death. The term used for animals, synonymous with autopsy (for humans)
-osisAbnormal conditionProptosisAbnormal forward placement of the eyeEyeball is either pushed forward in the eye socket or is partially out of the socket.
-ostomosis, -ostomy, -stomyTo furnish with an opening or mouthGastrostomyOpening the stomachSurgical opening of the stomach
-plastyDenoting molding or shapingRhinoplastyShaping the noseSurgical shaping of the nose
-rhagia, -rhagicDenoting discharge, usually bleedingHemorrhagicBloody dischargeBloody discharge
-rhaphyMeaning suturing or stitchingGastrorhaphySurgical repair of the stomach by sutureSurgical repair of the stomach by suture
-rheaMeaning a flow or dischargeDiarrheaRapid flow of fecal matterRapid flow of fecal matter
-scopeInstrument to visually examineEndoscopeInstrument used to view something withinInstrument used to view the inside of the gastrointestinal tract, or within another organ.
-scopyProcess of visually examiningGastroscopyVisual examination of the gastrointestinal tractVisual examination of the gastrointestinal tract
-sisState of conditionPrognosisForethought of knowledgeA forecast of the probable course of a patients condition/disease
-tome, -tomyInstrument to cut, process of cuttingOsteotomeInstrument that cuts boneA chisel-like knife for cutting bone

Combining Forms:

RootMeaningExampleDefinition of Example
Aer-, aeroDenoting gasAerophagicCondition of gulping air, filling the stomach with air
Alge-, algesi-, algo-Relating to painAnalgesiaWithout pain
Anomalo-Denoting irregularityAnomalyAn irregular finding
Arthro-Relating to a joint or jointsArthrodesisFusion of a joint
Brevi-ShortAbbreviateVery short, shortened
Celio-Denoting the abdomenCeliotomyIncision into the abdomen
Chol-, chole-, cholo-Relating to bileCholestasisStoppage of the bile flow
Chrom-, chromo-Relating to colorChromatophylicLikes color (takes up stain well, i.e. cells)
Cranio-Relating to the cranium of the skullCraniotomyA cut into the cranium
Cryano-, cryo-Denoting coldCryosurgerySurgery performed by freezing (with liquid nitrogen)
Crypt-To hide, a pitTonsilar cryptPocket of skin where the tonsils sit
Cyano-Dark blueCyanobacteriaPhotosynthesizing bacteria esp. in water
Cyclo-Pertaining to a cycleAcyclicWithout a cycle
Cysto-Relating to a sac or cystCystotomyIncision into a cyst (usually denoting the urinary bladder)
Cyto-Denoting a cellCytologyThe study of cells
Dacryo-Pertaining to the lacrimal glandsDacryosyrinxLacrimal duct
Dactylo-Relating to digitsPolydactylyMany digits (i.e. 6-toed cats)
Dent-, dento-, donto-Relating to teethDentalPertaining to the teeth
Derma-, dermat-Relating to the skinDermatophytosisCondition of skin fungus
Desmo-Relating to a bond or ligamentDesmitisInflammation of a ligament
Dextro-RightDextroversionVersion of the right, (i.e. movement of eyes to the right)
Diplo-Double, twofoldDiploidResembling a double or two of the same
Dorsi-, dorso-Referring to the backDorsalPertaining toward the vertebral column
Duodeno-Relating to the duodenumDuodenoscopyObserving the duodenum
Electro-Relating to electricityElectrocauteryBurning by electricity (or coagulating)
Encephalo-Denoting the brainEncephalitisInflammation of the brain
Entero-Relating to the intestinesEnterotomyIncision into the intestines
Eso-InwardEsophagusStructure that brings the food inward
Facio-Relating to the faceFacialPertaining to the face
Gero-, geronto-Denoting old ageGeriatricPertaining to the aged
Gingiva-Relating to the gingiva or gumGingivitisInflammation of the gingiva
Gloss-, glosso-Relating to the tongueHypoglossalUnder the tongue
Gluco-Denoting sweetnessGlucosuriaGlucose in the urine
Glyco-Relating to sugarGlycosuriaGlucose in the urine
Gnath-, gnatho-Denoting the jawPrognathicHaving a protruding jaw
Hist-, histio-, histo-Relating to a tissueHistopathologyMicroscopic examination of tissue for disease (what you do to a biopsy)
Hydr-, hydro-Denoting waterHydrocephalic“water” on the brain (excessive fluid retention in the cranium)
Ileo-Pertaining to the ileumIleocecalThe area where the ileum joins the cecum
Ipsi-Meaning selfIpsilateralOn the same side
Irido-Relating to a colored circleIridiodialysisSeparation or loosening of the iris from its attachments
Iso-EqualIsometricMeasures the same
Jejuno-Pertaining to the jejunumJejunostomySurgically created an opening in the jejunum
Kerato-Relating to the corneaKCS (Keratoconjunctivitis sicca) (inflammation and drying of the cornea and conjunctiva
Labio-Pertaining to the lipsLabialPertaining or toward the lips
Lacto-Relating to milkAgalactiaNot producing milk
Laparo-Pertaining to the loin or flankLaparoscopyVisualization of the abdominal cavity
Latero-Pertaining to the sideLateralPertaining to the side
Leido-, leio-SmoothLeiomyosarcomaSarcoma of the smooth muscle
Leuk-, leuko-Denoting deficiency of colorLeukocyte“White” blood cell
Lip-, lipo-Pertaining to fatLipomaFatty tumor
Litho-Denoting a calculusUrolithUrinary stone
Macr-, macro-Large, longMacrocyticLarge cells
Masti, mastro-Relating to the breastMastitisInflammation of the breast tissue
Meg-, mega-Great, largeSplenomegalyEnlarged spleen
Meningo-Denoting membranes, covering the brain and spinal cordMeningiomaTumor of the spinal membranes
Micr-, micro-Small in size or extentMicroscopicUnable to be seen by the naked eye
Mono-OneMonochromeOne color
Morpho-Relating to formMorphologicPertaining to the shape of something
Multi-ManyMultiparaMany viable births (i.e. as in cats)
My-, myo-Relating to muscleMyotomyIncision of a muscle
Myc-, mycet-Denoting a fungusMycoticPertaining to fungus like appearance
Myringo-Denoting tympani or the eardrumMyringectomyExcision of the eardrum
Myx-, myxo-Pertaining to mucusMyxovirusSynonym for influenza virus (mucus virus)
Naso-Relating to the noseNasopharyngealPertaining to the area where the nose and pharynx meet
Necro-Denoting deathNecroticPertaining to dead tissue
Neo-NewNeoplasmNew growth
Nephr-, nephro-Denoting the kidneyNephrotoxinToxic to the kidney
Normo-Normal or usualNormovolemiaNormal blood volume
Oculo-Denoting the eyeOculomotorNerve that controls eye movement
Onco-Denoting a swelling or massOncologyThe study of masses
Onycho-Relating to the nailsOnychectomyDeclaw (removal of toenail)
oo-Denoting an eggOocystEgg cell
Opisth-, opistho-BackwardOpisthotonosA form of spasm in which the head and tail are bent dorsally and the abdomen bent ventrally
Ophthal-, opthalmo-Pertaining to the eyeOphthalmoscopeInstrument to examine the eye
Optico-Relating to visionOpticalPertaining to the ability to see
Orchi-, orcho-Relating to the testesOrchiectomyRemoval of the testes
Oro-Relating to the mouthOronasalWhere the mouth meets the nasal passages
Ortho-Straight, rightOrthopedicPractice of correct function of the skeletal system
Osteo-Relating to the bonesOsteoporosisPathological loss of bone
Ot-, oto-Denoting an earOtoscopyVisual exam of the ear
Patho-Denoting diseasePathology The study of disease
Pedia-, pedo-Denoting a child or youngPediatricsPertaining to the study of the young/child
Perineo-Combining form for the region between the anus and scrotum or vulvaPerineumThe region between the anus and scrotum or vulva
Phago-Denoting a relationship to eatingPhagocytosisThe “eating” of cells or absorption of cells
Pharyngo-Pertaining to the pharynxPharyngotomyIncision into the pharynx
Phleb-, phlebo-Denoting the veinsPhlebitisInflammation of the veins
phot-, photo-Relating to lightPhotoperiodPeriod of light
Pilo-Relating to hairPiloerectionHair standing on end
Plasmo-Relating to plasma or the substance of a cellPlasmacytePlasma cell
Pneuma-, pneumono-, pneumoto-Denoting air or gasPneumonitisInflammation of lung tissue = pneumonia
Pod-, podo-Meaning footArthropodJointed foot (type of insect)
Poly-ManyPolydactylyMany digits
Ptyalo-Denoting salivaPtylectasisDilation of a salivary duct
Pulmo-Denoting the lungPulmonary Pertaining to the lungs/respiratory system
Pupillo-Denoting the pupilPapillary Pertaining to or emanating from the pupil
Pyel-, pyelo-Denoting the pelvis PyelonephritisInflammation of the renal pelvis
Pyloro-Relating to the pylorusPylorusThe distal aperture of the stomach or abomasums
Py-, pyo-Denoting pusPyonephritisInfection in the kidneys
Recto-Denoting the rectumRectoceleHernial protrusion of part of the rectum and colon
Rhin-, rhino-Denoting the noseRhinoscopyVisual exam of the nose
Sclero-Denoting hardnessSclerodermaHardened skin
Sero-Pertaining to serumSeromaSwelling of serum
Sinistro-LeftSinistrocerebralSituated in the left hemisphere of the brain
Somato-Denoting the bodySomaticPertaining to the body
Spasmo-Denoting a spasmSpasmodicPertaining to a spasm
Spermato-, spermo-Denoting spermSpermatocideAgent that destroys spermatozoa
Sphero-Denoting a sphere, roundSpherocyteRed blood cell with decreased volume that is round and dense (not biconcave)
Sphygma-Denoting a pulseSphygmomanometerInstrument for measuring arterial blood pressure
Spleen-, spleno-Denoting the spleenSplenomegalyEnlargement of the spleen
Staphyl-, staphylo-Resembling a bunch of grapesStaphylococcusA group of cocci
Steno-Narrow, shortStenosisNarrowing of an area
Steth-, stetho-Relating to the chestStethoscopeInstrument used to obtain an aural examination of the chest
Stomato-Denoting the mouthStomatocyteRed blood cell with the appearance of a mouth
Sym-, syn-With, along, togetherSymmetricalEqually on both sides
Tacho-, tarchy-SwiftTachycardicPertaining to a swift/fast heartbeat
Tarso-Relating to the flat of the footTarsalPertaining to the hind foot
Terato-Denoting a marvel, prodigy, or monsterTeratogenicProduction of a deformity in a developing embryo
Thoraco-Relating to the chestThoracocentesisPuncturing the chest with a needle
Thrombo-Denoting a clot of bloodThrombocyteA cell specialized for forming clots
Toxico-, toxo-Denoting poisonToxicology The study of poisons
Tracheo-Denoting the tracheaTracheostomyCreating an opening in the trachea
Trichi-, tricho-Denoting hairTrichoscopyExamination of the hair
Ur-, uro-, urono-Relating to urineUrinalysisExamination of urine
Vaso-Denoting a vesselVasoconstrictionConstriction of blood vessels
Veno-Denoting a veinVenipunctureSurgical puncture a vein
Ventri-, ventro-Denoting the abdomenVentralPertaining to the abdomen in non humans
Vertebro-Relating to the vertebraVertebral Pertaining to the vertebra
Viscero-Denoting the organs of the bodyVisceral Pertaining to the surface of the internal organs
vivi-Denoting aliveViviparousGiving birth to living young which develop within the maternal body
Xantho-Denoting yellowXanthochromicYellow colored
Xero-Denoting drynessXerodermaA mild form of ichthyosis, excessive dryness of the skin

Terminology frequently used to designate body parts of organs:

Body part/organMedical terminology
AnusAnal, ano-
ArmBrachial, brachio-
BloodHem-, hemo-, hemat-
ChestThoracic, thorax, thoraco
EarAuricle, oto-
EyeOcular, oculo-, ophthalmo-
Foot Pedal, ped-, -pod
GallbladderChole-, chol-
HeadCephalic, cephalo-
HeartCarium, cardiac, cardio-
IntestinesCecum, colon, duodenum, ileum, jejunum
KidneyRenal, nephric, nephro-
LipCheil-, labi-
LiverHepatic, hepato
LungsPulmonary, pulmonic
MouthOral, os, stoma, stomat-
NeckCervix, cervical, cervico-
SkinDerma, integumentum
StomachGastric, gastro-
TesticleOrchio-, orchi-, orchido-
Urinary bladderCysti-, cysto-
UterusHystero-, metra
VaginaVulvo, vaginal

Planes and terms relative to the animal body:

Mesial – in or near the middle of the dental arcade
Axial – pertaining to or with respect to the axial skeleton (head, vertebrae, rib cage
Sagittal – a plane or section parallel to the median plane of the body, separates body into right and left
Oblique – slanted or inclined plane
Transverse – separates body into front and back
Lateral – pertaining to a side
Ventral – pertaining to the belly, abdomen, or underside of the body, opposite of dorsal
Dorsal – pertaining to the back or top of the body, opposite of ventral
Cranial – pertaining to the head or cranium
Caudal – pertaining to the hind end or tail
Frontal – plane that separates the body into top and bottom
Rostral – pertaining to the nose
Palmar – pertaining to the pads or bottom of the foot (as would be the human palm)
Plantar – pertaining to the sole or caudal aspect of the digit
Proximal – nearest to a point of reference or point of attachment
Distal – furthest to a point of reference or point of attachment

Courtesy of Nanette Walker Smith, RVT, CVT and Elizabeth Warren, RVT

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Clinical Pathology
Critical Care - Triage
Emergency-Receptionist tips
Medical Calculations
Medical Records
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