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:
Prefix
Meaning
Example
Literal Translation
Actual Definition
a-, ab-, abs
No, not
Agalactia
Condition of no milk
Partial or complete absence of milk
flow in the absence of mammary gland
disease
Ad-
Toward, near
Adduct
To draw toward the
median
Movement towards the median or
central line
Amb-, ambi-
Both
Ambidextrous
Both right
Having the ability to work effectively
with either hand
Amphi-
On both sides
Amphiarthrosis
Joined on both sides
Joint which surfaces are connected by
fibrocartilage (allows very little
movement)
An-
No, not
Anemia
Without blood
Decreased number of red blood cells
(erythrocytes) or the amount of
hemoglobin in the erythrocytes
Ant-, anti-
Against
Antibiotic
Against life
Destructive of life
Auto-
Self
Autonomic
Pertaining to ones
nerves
(Neurologically) – not subject to
voluntary control
Ana-
Up, apart
Anatomy
Process of cutting
apart
The science dealing with the form and
structure of living organisms
Bili-
Pertaining to
bile
Biliary
Pertaining to the bile
Pertaining to the bile, bile ducts, or gall
bladder
Brady-
Slow
Bradycardic
Slow heart
A slow heart rhythm
Broncho-
Relating to
bronchi
Bronchiole
Small bronchi
The very small branches of the bronchi
Cardi-,
cardio-
Relating to the
heart
Cardiac
Pertaining to the
heart
Pertaining to the heart
Cervico-
Relating to the
neck
Cervical
Pertaining to the
cervical region
Pertaining to the cervical region
Circa
About
Circadian
About the day
A daily rhythm or daily occurrence
Circum
Around
Circumference
Around the outside
Measurement around the outside of a
structure
Co-
Work together
Coagulant
Work together to
form clot
To cause a clot
Con-
Together with
Concussion
Together with blow
Violent jar or shock that results in
severe injury
Contra-
Against,
proposed
Contralateral
Against the side
Pertaining to, situated on, or affecting
the opposite side
Di-
Twice
Diarticular
Two joints
Pertaining to two joints
Dia-
Through,
complete
Diagnose
Knowledge of a
condition
To identify or recognize a disease
Dialy-
To separate
Dialysis
To separate break
apart
Process of separating components of a
fluid and maintain viability
En-
Inward
Encephalic
In the head
Pertaining to the brain; within the skull
Endo-
Within, inner
Endocrine
Secrete within
Pertaining to internal secretions
Epi-
Above
Epidermis
Pertaining to the skin
The outer layer of skin
above
Ex-
Out
Excise
To cut out
Exo-
Outside of,
Exogenous
Pertaining to outward Originating outside or caused by
To remove by cutting
outward
production
factors outside the organism
Extra-label
Outside of the label
Use of a drug in a way or for a purpose
not specified on the label
Relating to
fibers
Fibrosarcoma
Fiber cancer
Sarcoma made of fibrous tissue
Gaster-,
gastr-,
gastro-
Pertaining to
the stomach
Gastrotomy
Cut in the stomach
Surgical incision into the stomach
Hemi-
Half
Hemilaminectomy
Removal of half the
lamina
Removal of a vertebral lamina on one
side only
Hemo-
Relating to the
blood
Hemogram
Blood report/graph
Report of the blood parameters
Hepat-,
hepatico-,
hepato-
Pertaining to
the liver
Hepatic
Pertaining to the liver Pertaining to the liver
Homeo-
Denoting
likeness or
resemblance
Homeopathy
The study of like
diseases
Study of treating disease in a sick
animal with drugs capable of producing
the same response in a healthy animal
Homo-
Same, similar
Homogeneous
Generated the same
Of uniform quality, composition or
structure
Hyal-
Clear,
transparent
Hyaline
Clear, transparent
Pertaining to a clear/transparent
appearance of a cast or membrane
Hyper-
Excessive,
above
Hypertrophic
Pertaining to
excessive food
Increase in volume of a tissue or organ
produced entirely by enlargement of
existing cells (over nourishment)
Hypo-
Below,
deficient
Hypothyroid
Deficient thyroid
Deficient thyroid gland activity
Idio-
Relationship to
one's self or
something
separate and
distinct
Idiopathic
Pertaining to a
disease
Pertaining to a disease with an
unknown origin
In-
Not, in, inside,
within
Ingesta
Material within
Material taken into the body by mouth
Infra-
Below
Infraorbital
Pertaining to below
the eye
Pertaining to below the eye
Intra-
Within
Intrauterine
Within the uterus
Within the uterus
Iso-
Equal, alike
Isometric
Equal measure
Equal measure
Karyo-
Relating to a
cell's nucleus
Karyocyte
Nucleated cell
Nucleated cell
Laryngo-
Pertaining to
the larynx
Laryngospasm
Spasm of the larynx
Spasmodic closure of the larynx (seen
in cats)
Medi-
Middle
Mediastinum
Middle of the
sternum
The membranes that separate the
thorax into right and left at the
sternum and vertebral column
Myelo-
Pertaining to
the spinal cord
or bone
marrow
Myelogram
Injection of a dye into the space
A record of the spinal
around the spinal column to produce a
cord
specific image on a radiograph
Ovari-,
ovario-
Pertaining to
the ovary
Ovariohysterectomy
Removal of the
ovaries and uterus
Surgical removal of the ovaries and
uterus
Omni-
All
Omnivore
One that eats all
Animal that eats both plants and meat
(i.e. dog)
Peri-
Surrounding,
around
Perivascular
Pertaining to around
a vessel
Around a vessel
Post-
Behind, after
Postsurgical
After surgery
After surgery
Pre-, Pro-
Before, in front
of, favoring
Prognathism
Condition before the
jaw
Abnormal protrusion of one or both
jaws, especially the lower one
Pseudo-
False
Pseudopregnancy
False pregnancy
False pregnancy
Re-
Back
Recheck
Check back
Re-examination of a patient
Retro-
Behind
Retrograde
Going backward
Going backward
Semi-
Half
Semicircular
Half circle
Half circle
Steato-
Fatty
Steatitis
Fat inflammation
Inflammation of fatty tissue
Extra-
Outside of; in
addition to
Fibro-
Sub-
Under, near
Under the mandible
Under the mandible
Syn-
Joined together Synarthrosis
Submandibular
Joint joined together
Essentially a fused joint (skull suture)
Trans-
Across,
through,
beyond
Transplacental
Across the placenta
Through the placenta
Un-
Not, reversal
Unconscious
Not conscious
Not conscious
Suffix
Meaning
Example
Literal Translation
Actual Definition
-able, -ible, ble
The power to
be
Palpable
The power to feel
Able to feel something
-ac
Pertaining to
Cardiac
Pertaining to the
heart
Pertaining to the heart
-al
Pertaining to
Neural
Pertaining to a nerve
or nerves
Pertaining to a nerve or nerves
-algia
Pain
Arthralgia
Pain of the joint
Pain in a joint
-ase
Forms the
name of an
enzyme
Asparaginase
Enzyme
Enzyme that catalyzes the deamination
of asparagine
-blast
Designates a
Myeloblast
cell or structure
Bone marrow cell
Immature cell of the bone marrow
-cele
Denoting a
swelling
Sialocele
Swelling of the
salivary gland
Swelling of the salivary gland
-centesis
Denoting a
puncture
Cystocentesis
Puncture of a cyst
Commonly known as a needle aspirate
of bladder contents
-cyte
Cell
Erythrocyte
Red blood cell
Red blood cell
-ectomy
Excision
Lumpectomy
Excision of a lump
Excision of a lump
-emia
Blood condition
Lipemia
Fat in the blood
An excess of lipids in the blood
-esthesia
Denoting
sensation
Anesthesia
Without sensation
Without sensation
-gene, genesis, genetic, genic
Denoting
production,
origin
Angiogenesis
Blood vessel origin
The development of blood vessels
-gram
A tracing, a
mark
Echocardiogram
Echo tracing of the
heart
The record produced by sound wave
examination of the heart
-graph
A writing, a
record
Electrocardiograph
Record of
electrocardiogram
The record produced by electrical
tracings of the heart
-ia
Condition
Leukopenia
Decreased white
blood cells
Reduction of the number of leukocytes
(white blood cells) in the blood
-iasis
Denoting a
condition or
Atelectasis
pathologic state
Condition of collapsed
Collapsed or airless lung tissue
lung
-ic
Pertaining to
Gastric
Pertaining to the
stomach
Pertaining to, affecting, or originating in
the stomach
-ist
One who
specializes in
Nephrologist
Person specializing in
kidneys
Veterinarian specializing in the study of
kidneys
-itis
Inflammation
Pancreatitis
Inflammation of the
pancreas
Inflammation of the pancreas
-logy
Process of
study
Zoology
The study of animals
The biological study of animals
-oid
Denoting form
or resemblance
Opioid
Like an opiate
Synthetic narcotic that acts like an
opiate
-oma
Tumor, mass
Hematoma
Mass of blood
A localized collection of extravasated
blood, usually clotted, in an organ,
space, or tissue
-opsy
Process of
viewing
Necropsy
Viewing of a
deceased body
Examination of a body after death. The
term used for animals, synonymous
with autopsy (for humans)
-osis
Abnormal
condition
Proptosis
Abnormal forward
placement of the eye
Eyeball is either pushed forward in the
eye socket or is partially out of the
socket.
-ostomosis, ostomy, stomy
To furnish with
an opening or
mouth
Gastrostomy
Opening the stomach
Surgical opening of the stomach
-plasty
Denoting
molding or
shaping
Rhinoplasty
Shaping the nose
Surgical shaping of the nose
-rhagia, rhagic
Denoting
discharge,
usually
bleeding
Hemorrhagic
Bloody discharge
Bloody discharge
-rhaphy
Meaning
suturing or
stitching
Gastrorrhaphy
Surgical repair of the
stomach by suture
Surgical repair of the stomach by
suture
-rhea
Meaning a flow
or discharge
Diarrhea
Rapid flow of fecal
matter
Rapid flow of fecal matter
-scope
Instrument to
visually
examine
Endoscope
Instrument used to
view something
within
Instrument used to view the inside of
the gastrointestinal tract, or within
another organ.
-scopy
Process of
visually
examining
Gastroscopy
Visual examination of
the gastrointestinal
tract
Visual examination of the
gastrointestinal tract
-sis
State of
condition
Prognosis
Forethought of
knowledge
A forecast of the probable course of a
patients condition/disease
-tome, -tomy
Instrument to
cut, process of
cutting
Osteotome
Instrument that cuts
bone
A chisel-like knife for cutting bone
Combining Forms:
Root
Meaning
Example
Definition of Example
Aer-, aero
Denoting gas
Aerophagic
Condition of gulping air, filling the
stomach with air
Alge-, algesi-,
algo-
Relating to pain
Analgesia
Without pain
Anomalo-
Denoting irregularity
Anomaly
An irregular finding
Arthro-
Relating to a joint or joints
Arthrodesis
Fusion of a joint
Brevi-
Short
Abbreviate
Very short, shortened
Celio-
Denoting the abdomen
Celiotomy
Incision into the abdomen
Chol-, chole-,
cholo-
Relating to bile
Cholestasis
Stoppage of the bile flow
Chrom-, chromo-
Relating to color
Chromatophilic
Likes color (takes up stain well, i.e.
cells)
Cranio-
Relating to the cranium of the
Craniotomy
skull
A cut into the cranium
Cryano-, cryo-
Denoting cold
Cryosurgery
Surgery performed by freezing (with
liquid nitrogen)
Crypt-
To hide, a pit
Tonsillarcrypt
Pocket of skin where the tonsils sit
Cyano-
Dark blue
Cyanobacteria
Photosynthesizing bacteria esp. in water
Cyclo-
Pertaining to a cycle
Acyclic
Without a cycle
Cysto-
Relating to a sac or cyst
Cystotomy
Incision into a cyst (usually denoting the
urinary bladder)
Cyto-
Denoting a cell
Cytology
The study of cells
Dacryo-
Pertaining to the lacrimal
glands
Dacryosyrinx
Lacrimal duct
Dactylo-
Relating to digits
Polydactyly
Many digits (i.e. 6-toed cats)
Dent-, dento-,
donto-
Relating to teeth
Dental
Pertaining to the teeth
Derma-, dermat-
Relating to the skin
Dermatophytosis
Condition of skin fungus
Desmo-
Relating to a bond or ligament Desmitis
Inflammation of a ligament
Dextro-
Right
Version of the right, (i.e. movement of
eyes to the right)
Dextroversion
Diplo-
Double, twofold
Diploid
Resembling a double or two of the same
Dorsi-, dorso-
Referring to the back
Dorsal
Pertaining toward the vertebral column
Duodeno-
Relating to the duodenum
Duodenoscopy
Observing the duodenum
Electro-
Relating to electricity
Electrocautery
Burning by electricity (or coagulating)
Encephalo-
Denoting the brain
Encephalitis
Inflammation of the brain
Entero-
Relating to the intestines
Enterotomy
Incision into the intestines
Eso-
Inward
Esophagus
Structure that brings the food inward
Facio-
Relating to the face
Facial
Pertaining to the face
Gero-, geronto-
Denoting old age
Geriatric
Pertaining to the aged
Gingiva-
Relating to the gingiva or gum Gingivitis
Inflammation of the gingiva
Gloss-, glosso-
Relating to the tongue
Hypoglossal
Under the tongue
Gluco-
Denoting sweetness
Glucosuria
Glucose in the urine
Glyco-
Relating to sugar
Glycosuria
Glucose in the urine
Gnath-, gnatho-
Denoting the jaw
Prognathic
Having a protruding jaw
Hist-, histio-,
histo-
Relating to a tissue
Histopathology
Microscopic examination of tissue for
disease (what you do to a biopsy)
Hydr-, hydro-
Denoting water
Hydrocephalic
“water” on the brain (excessive fluid
retention in the cranium)
Ileo-
Pertaining to the ileum
Ileocecal
The area where the ileum joins the
cecum
Ipsi-
Meaning self
Ipsilateral
On the same side
Irido-
Relating to a colored circle
Iridodialysis
Separation or loosening of the iris from
its attachments
Iso-
Equal
Isometric
Measures the same
Jejuno-
Pertaining to the jejunum
Jejunostomy
Surgically created an opening in the
jejunum
Kerato-
Relating to the cornea
KCS
(Keratoconjunctivitis
sicca)
(inflammation and drying of the cornea
and conjunctiva
Labio-
Pertaining to the lips
Labial
Pertaining or toward the lips
Lacto-
Relating to milk
Agalactia
Not producing milk
Laparo-
Pertaining to the loin or flank
Laparoscopy
Visualization of the abdominal cavity
Latero-
Pertaining to the side
Lateral
Pertaining to the side
Leido-, leio-
Smooth
Leiomyosarcoma
Sarcoma of the smooth muscle
Leuk-, leuko-
Denoting deficiency of color
Leukocyte
“White” blood cell
Lip-, lipo-
Pertaining to fat
Lipoma
Fatty tumor
Litho-
Denoting a calculus
Urolith
Urinary stone
Macr-, macro-
Large, long
Macrocytic
Large cells
Masti, mastro-
Relating to the breast
Mastitis
Inflammation of the breast tissue
Meg-, mega-
Great, large
Splenomegaly
Enlarged spleen
Meningo-
Denoting membranes,
covering the brain and spinal
cord
Meningioma
Tumor of the spinal membranes
Micr-, micro-
Small in size or extent
Microscopic
Unable to be seen by the naked eye
Mono-
One
Monochrome
One color
Morpho-
Relating to form
Morphologic
Pertaining to the shape of something
Multi-
Many
Multipara
Many viable births (i.e. as in cats)
My-, myo-
Relating to muscle
Myotomy
Incision of a muscle
Myc-, mycet-
Denoting a fungus
Mycotic
Pertaining to fungus like appearance
Myringo-
Denoting tympani or the
eardrum
Myringectomy
Excision of the eardrum
Myx-, myxo-
Pertaining to mucus
Myxovirus
Synonym for influenza virus (mucus
virus)
Naso-
Relating to the nose
Nasopharyngeal
Pertaining to the area where the nose
and pharynx meet
Necro-
Denoting death
Necrotic
Pertaining to dead tissue
Neo-
New
Neoplasm
New growth
Nephr-, nephro-
Denoting the kidney
Nephrotoxin
Toxic to the kidney
Normo-
Normal or usual
Normovolemia
Normal blood volume
Oculo-
Denoting the eye
Oculomotor
Nerve that controls eye movement
Onco-
Denoting a swelling or mass
Oncology
The study of masses
Onycho-
Relating to the nails
Onychectomy
Declaw (removal of toenail)
oo-
Denoting an egg
Oocyst
Egg cell
Opisth-, opistho-
Backward
Opisthotonos
A form of spasm in which the head and
tail are bent dorsally and the abdomen
bent ventrally
Ophthal-,
opthalmo-
Pertaining to the eye
Ophthalmoscope
Instrument to examine the eye
Optico-
Relating to vision
Optical
Pertaining to the ability to see
Orchi-, orcho-
Relating to the testes
Orchiectomy
Removal of the testes
Oro-
Relating to the mouth
Oronasal
Where the mouth meets the nasal
passages
Ortho-
Straight, right
Orthopedic
Practice of correct function of the
skeletal system
Osteo-
Relating to the bones
Osteoporosis
Pathological loss of bone
Ot-, oto-
Denoting an ear
Otoscopy
Visual exam of the ear
Patho-
Denoting disease
Pathology
The study of disease
Pedia-, pedo-
Denoting a child or young
Pediatrics
Pertaining to the study of the
young/child
Perineo-
Combining form for the region
between the anus and
Perineum
scrotum or vulva
The region between the anus and
scrotum or vulva
Phago-
Denoting a relationship to
eating
Phagocytosis
The “eating” of cells or absorption of
cells
Pharyngo-
Pertaining to the pharynx
Pharyngotomy
Incision into the pharynx
Phleb-, phlebo-
Denoting the veins
Phlebitis
Inflammation of the veins
phot-, photo-
Relating to light
Photoperiod
Period of light
Pilo-
Relating to hair
Piloerection
Hair standing on end
Plasmo-
Relating to plasma or the
substance of a cell
Plasmacyte
Plasma cell
Pneuma-,
pneumono-,
pneumoto-
Denoting air or gas
Pneumonitis
Inflammation of lung tissue =
pneumonia
Pod-, podo-
Meaning foot
Arthropod
Jointed foot (type of insect)
Poly-
Many
Polydactyly
Many digits
Ptyalo-
Denoting saliva
Ptyalectasis
Dilation of a salivary duct
Pulmo-
Denoting the lung
Pulmonary
Pertaining to the lungs/respiratory
system
Pupillo-
Denoting the pupil
Pupillary
Pertaining to or emanating from the
pupil
Pyel-, pyelo-
Denoting the pelvis
Pyelonephritis
Inflammation of the renal pelvis
Pyloro-
Relating to the pylorus
Pylorus
The distal aperture of the stomach or
abomasums
Py-, pyo-
Denoting pus
Pyonephritis
Infection in the kidneys
Recto-
Denoting the rectum
Rectocele
Hernial protrusion of part of the rectum
and colon
Rhin-, rhino-
Denoting the nose
Rhinoscopy
Visual exam of the nose
Sclero-
Denoting hardness
Scleroderma
Hardened skin
Sero-
Pertaining to serum
Seroma
Swelling of serum
Sinistro-
Left
Sinistrocerebral
Situated in the left hemisphere of the
brain
Somato-
Denoting the body
Somatic
Pertaining to the body
Spasmo-
Denoting a spasm
Spasmodic
Pertaining to a spasm
Spermato-,
Denoting sperm
Spermaticide
Agent that destroys spermatozoa
spermoSphero-
Denoting a sphere, round
Spherocyte
Red blood cell with decreased volume
that is round and dense (not biconcave)
Sphygma-
Denoting a pulse
Sphygmomanometer
Instrument for measuring arterial blood
pressure
Spleen-, spleno-
Denoting the spleen
Splenomegaly
Enlargement of the spleen
Staphyl-,
staphylo-
Resembling a bunch of grapes Staphylococcus
A group of cocci
Steno-
Narrow, short
Stenosis
Narrowing of an area
Steth-, stetho-
Relating to the chest
Stethoscope
Instrument used to obtain an aural
examination of the chest
Stomato-
Denoting the mouth
Stomatocyte
Red blood cell with the appearance of a
mouth
Sym-, syn-
With, along, together
Symmetrical
Equally on both sides
Tacho-, tachy-
Swift
Tachycardic
Pertaining to a swift/fast heartbeat
Tarso-
Relating to the flat of the foot
Tarsal
Pertaining to the hind foot
Terato-
Denoting a marvel, prodigy,
or monster
Teratogenic
Production of a deformity in a developing
embryo
Thoraco-
Relating to the chest
Thoracocentesis
Puncturing the chest with a needle
Thrombo-
Denoting a clot of blood
Thrombocyte
A cell specialized for forming clots
Toxico-, toxo-
Denoting poison
Toxicology
The study of poisons
Tracheo-
Denoting the trachea
Tracheostomy
Creating an opening in the trachea
Trichi-, tricho-
Denoting hair
Trichoscopy
Examination of the hair
Ur-, uro-, urono-
Relating to urine
Urinalysis
Examination of urine
Vaso-
Denoting a vessel
Vasoconstriction
Constriction of blood vessels
Veno-
Denoting a vein
Venipuncture
Surgical puncture a vein
Ventri-, ventro-
Denoting the abdomen
Ventral
Pertaining to the abdomen in non
humans
Vertebro-
Relating to the vertebra
Vertebral
Pertaining to the vertebra
Viscero-
Denoting the organs of the
body
Visceral
Pertaining to the surface of the internal
organs
vivi-
Denoting alive
Viviparous
Giving birth to living young which
develop within the maternal body
Xantho-
Denoting yellow
Xanthochromic
Yellow colored
Xero-
Denoting dryness
Xeroderma
A mild form of ichthyosis, excessive
dryness of the skin
Terminology frequently used to designate body parts of organs:
Body part/organ
Medical terminology
Air
Pneumo
Anus
Anal, ano-
Arm
Brachial, brachio-
Blood
Hem-, hemo-, hemat-
Chest
Thoracic, thorax, thoraco
Ear
Auricle, oto-
Eye
Ocular, oculo-, ophthalmo-
Foot
Pedal, ped-, -pod
Gallbladder
Chole-, chol-
Head
Cephalic, cephalo-
Heart
Carium, cardiac, cardio-
Intestines
Cecum, colon, duodenum, ileum, jejunum
Kidney
Renal, nephric, nephro-
Lip
Cheil-, labi-
Liver
Hepatic, hepato
Lungs
Pulmonary, pulmonic
Mouth
Oral, os, stoma, stomat-
Muscle
Myo-
Neck
Cervix, cervical, cervico-
Penis
Penile
Rectum
Rectal
Skin
Derma, integumentum
Stomach
Gastric, gastro-
Testicle
Orchio-, orchi-, orchido-
Urinary bladder
Cysti-, cysto-
Uterus
Hystero-, metra
Vagina
Vulvo, 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