A–Z Medical Term Directory

A real-time, non-invasive imaging modality using high-frequency sound waves to visualize internal soft tissue organ architecture and fluid.

A diagnostic or therapeutic puncture of the abdominal wall using a needle or catheter to aspirate free peritoneal fluid.

An endocrine blood test that evaluates adrenal gland reserve capacity by measuring blood cortisol before and after injecting synthetic adrenocorticotropic hormone.

An endocrine deficiency where the adrenal glands fail to produce vital steroid hormones (cortisol and aldosterone).

An informal yet universally recognized veterinary clinical shorthand for "Ain’t Doing Right," denoting vague, non-specific malaise or illness without localized signs.

Paired, small endocrine glands located immediately in front of each kidney that produce vital stress hormones, steroid hormones, and adrenaline.

A liver enzyme found inside liver cells that leaks into the bloodstream when hepatocytes are damaged or inflamed.

An inducible enzyme found on the biliary membranes of the liver, bone cells, and (in dogs) induced by steroid hormones.

A potentiated broad-spectrum aminopenicillin antibiotic combined with a beta-lactamase inhibitor to treat skin, urinary, and respiratory bacterial infections.

The complete lack or loss of appetite and refusal to consume food.

A targeted Janus kinase (JAK) inhibitor that selectively stops the itch and inflammation pathway in allergic dogs.

The abnormal pathologic accumulation of free fluid within the peritoneal cavity, causing abdominal distension.

An uncoordinated, clumsy, or stumbling gait caused by sensory or neurological dysfunction without weakness or paralysis.

A clinical demeanor assessment denoting an animal that is mentally alert, visually interactive, and energetically engaged with their environment.

A prescription abbreviation originating from Latin meaning "bis in die," directing a medication to be given twice a day, approximately 12 hours apart.

Involuntary, spasmodic contraction of the orbicularis oculi muscle causing squinting or tightly shut eyelids in response to ocular pain.

A metabolic waste product of dietary protein digestion and liver metabolism, excreted primarily by the kidneys.

A potent partial mu-opioid agonist providing excellent analgesia, uniquely well-absorbed across feline oral mucous membranes.

A polygenic developmental disorder of the hip joint leading to joint laxity, abnormal biomechanical wear, and secondary osteoarthritis.

An endocrine disorder in dogs caused by underactive thyroid glands that fail to produce adequate thyroid hormones.

A highly contagious and severe viral illness in puppies and unvaccinated dogs that attacks rapidly dividing cells in the intestinal crypts and bone marrow.

A veterinary non-steroidal anti-inflammatory drug (NSAID) prescribed to relieve pain and inflammation associated with osteoarthritis and surgery in dogs.

An opacity or cloudiness of the crystalline lens inside the eye that obstructs the passage of light to the retina.

A first-generation bactericidal cephalosporin antibiotic that inhibits bacterial cell wall synthesis, premier for canine bacterial pyoderma.

A condition in which the tear-producing gland of the third eyelid prolapses and pops out of its normal anatomical pocket, appearing as a red fleshy mass.

A gradual, irreversible loss of kidney filtration, waste excretion, and urine concentration ability over months or years.

The spiral, snail-shell-shaped bony cavity of the inner ear housing the organ of Corti for acoustic sensory transduction.

A core laboratory panel that quantifies and evaluates the three primary cellular components of blood: red blood cells, white blood cells, and platelets.

An advanced cross-sectional imaging technique that uses rotating X-rays and computer processing to create detailed three-dimensional volumetric images.

A clinical syndrome where the heart cannot pump adequate blood forward, causing fluid to congest and back up into the lungs or body cavities.

The transparent, convex front surface of the eyeball that admits light and provides the major refractive optical power of the eye.

A painful wound or break in the outer epithelial layers of the cornea on the surface of the eye.

A sudden, explosive defensive reflex to clear the airways of mucus, foreign material, or irritating secretions.

A vital stabilizing ligament inside the knee joint (stifle) that prevents the shin bone from sliding forward relative to the thigh bone.

A waste byproduct of normal muscle breakdown excreted exclusively by the kidneys; the primary blood biomarker for renal filtration and IRIS staging.

A physical examination assessment measuring the time in seconds it takes for blanched mucous membrane color to return, assessing peripheral perfusion and blood circulation.

An endocrine disorder caused by excessive, prolonged levels of cortisol hormone in the body.

A surgical incision into the urinary bladder, most frequently performed to remove bladder stones (uroliths) or biopsy bladder tumors.

The microscopic evaluation of cells collected from body fluids, ear exudate, skin scrapings, or fine-needle aspirates.

An injectable, caninized monoclonal antibody that targets and neutralizes interleukin-31 (IL-31) to relieve allergic itching in dogs.

A comprehensive medical procedure performed under general anesthesia to scale plaque and calculus above and below the gumline, polish tooth surfaces, and take dental radiographs.

A chronic metabolic disorder characterized by inadequate insulin production or cellular insulin resistance, resulting in elevated blood glucose.

A broad-spectrum tetracycline antibiotic that inhibits bacterial protein synthesis, used for tick-borne diseases and respiratory infections.

Difficult, labored, or painful breathing indicating an inability to ventilate lungs or oxygenate blood adequately.

A non-invasive ultrasound examination of the heart that evaluates cardiac chamber dimensions, muscle thickness, valve function, and blood flow velocity.

A potent bactericidal fluoroquinolone antibiotic targeting bacterial DNA gyrase, used for severe Gram-negative infections.

The surgical removal of the eyeball and associated eyelid margins, usually performed for blind, persistently painful, or cancerous eyes.

Hemorrhage originating from the nasal cavity, nostrils, or nasopharynx, manifesting as unilateral or bilateral bleeding.

The muscular tube conveying food and liquids from the pharynx down to the stomach via coordinated peristaltic contractions.

An H2-receptor antagonist that reduces gastric acid secretion to soothe stomach upset, ulcers, and acid reflux.

A microscopic parasitological test utilizing high-density flotation solutions and centrifugal force to concentrate and identify intestinal parasite eggs and cysts.

A common endocrine disorder of older cats caused by an overactive thyroid gland that overproduces thyroid hormones, accelerating metabolism.

A lentivirus infection of cats that gradually depletes CD4+ helper T-lymphocytes, leading to progressive immune dysfunction.

A severe, immune-mediated viral disease in cats caused by a mutation of common feline coronavirus (FCoV).

A contagious feline retrovirus transmitted primarily through close, friendly contact that impairs the immune system and predisposes cats to tumors and bone marrow failure.

An umbrella term encompassing disorders affecting the feline urinary bladder and urethra, including feline idiopathic cystitis, bladder stones, and urethral plugs.

The major long bone of the hindlimb extending from the hip joint to the stifle (knee) joint.

A quick, minimally invasive diagnostic procedure using a fine needle to collect cells from a lump, organ, or fluid for microscopic cytology.

An in-clinic ELISA blood test that simultaneously screens cats for Feline Immunodeficiency Virus antibodies and Feline Leukemia Virus antigens.

An ophthalmic diagnostic test utilizing water-soluble orange-fluorescent dye to detect corneal epithelial defects, ulcers, and nasolacrimal drainage.

A potent loop diuretic that inhibits sodium and water reabsorption in the kidneys to rapidly clear fluid accumulation from heart failure.

An analogue of the neurotransmitter GABA used for managing neuropathic and chronic pain, situational feline anxiety, and adjunct seizure control.

A catastrophic medical and surgical emergency where the stomach fills with gas and twists on its mesenteric axis, cutting off blood supply.

A minimally invasive diagnostic and therapeutic procedure using a flexible video endoscope to visualize the esophagus, stomach, and duodenum.

A surgical procedure that permanently attaches the stomach to the abdominal body wall to prevent gastric dilatation-volvulus (GDV / bloat).

A microscopic flagellated protozoan intestinal infection causing malabsorptive soft stool, mucus diarrhea, and weight loss.

An ocular emergency characterized by increased intraocular pressure (IOP) that causes severe eye pain and rapid irreversible blindness.

The microscopic functional filtration unit of the kidney that filters waste products and water from the blood while retaining vital proteins.

An offensive, foul, or abnormal odor emanating from the oral cavity, typically caused by periodontal disease, oral necrosis, or systemic metabolic illness.

An in-clinic ELISA or lateral-flow immunoassay detecting uterine glycoprotein antigens secreted by mature adult female Dirofilaria immitis heartworms.

A serious, potentially fatal parasitic infection caused by foot-long worms residing in the pulmonary arteries and heart.

The passage of fresh, bright red blood in or on the stool, originating from the lower gastrointestinal tract (colon, rectum, or anus).

The percentage of whole blood volume made up of red blood cells, providing the primary measure of anemia and hydration status.

The presence of red blood cells in the urine, giving it a pink, red, or brownish discoloration.

A neurosurgical spinal decompression procedure that removes one side of a vertebral lamina to access and extract herniated intervertebral disc material crushing the spinal cord.

A classic neurological complex of four distinct eye signs caused by a disruption of the sympathetic nerve pathway to the eye.

The frequency of cardiac ventricular contractions, measured in beats per minute (bpm).

A yellow discoloration of the skin, sclera (whites of the eyes), gums, and mucous membranes caused by high levels of bilirubin in the blood.

A chronic neurological brain condition characterized by recurrent, unprovoked seizures without an identifiable structural brain defect or toxin.

An injection route abbreviation designating administration of medication directly into a muscle belly.

Fibrocartilaginous shock-absorbing pads situated between adjacent vertebrae along the spinal column.

A spinal condition where cushioning discs between vertebrae degenerate, bulge, or rupture into the spinal canal, compressing the spinal cord.

An administration route abbreviation designating delivery of fluids or medications directly into a vein.

A highly contagious upper respiratory syndrome in dogs causing a sudden, harsh, dry hacking cough.

Paired retroperitoneal organs that filter metabolic waste from the blood, balance fluids and electrolytes, and concentrate urine.

A serious, zoonotic bacterial infection transmitted through contaminated water or wildlife urine that causes acute kidney failure and liver damage.

An abnormal state of drowsiness, sluggishness, low energy, and reluctance to engage in normal physical activity.

A modern anticonvulsant targeting synaptic vesicle protein SV2A, renowned for its wide safety margin and minimal liver burden.

A synthetic isomer of levothyroxine (T4) used as lifelong daily hormone replacement therapy for canine hypothyroidism.

The largest internal metabolic and detoxifying organ in the body, positioned cranial to the stomach behind the diaphragm.

An 8-hour dynamic endocrine test that screens for Cushing’s disease and differentiates pituitary-dependent from adrenal-dependent forms.

Small, bean-shaped immune filtration organs positioned along lymphatic vessels throughout the body.

A malignant cancer arising from lymphocytes, a type of white blood cell vital to the immune system.

A premier diagnostic imaging modality utilizing powerful magnetic fields and radio waves to generate exquisite soft-tissue contrast of the brain, spinal cord, and nerves.

A neurokinin-1 (NK1) receptor antagonist antiemetic used to prevent and treat vomiting and motion sickness.

A malignant skin cancer arising from mast cells, specialized immune cells that contain bioactive granules of histamine and heparin.

The passage of dark, black, sticky, tar-like feces containing digested blood originating from the upper gastrointestinal tract.

An antithyroid drug that inhibits the production of thyroid hormones to manage feline hyperthyroidism.

A synthetic nitroimidazole antibiotic and antiprotozoal medication with anti-inflammatory bowel properties.

A tetracyclic antidepressant that antagonizes central presynaptic alpha-2 and serotonin receptors, used as a powerful appetite stimulant.

A dual-leaflet one-way heart valve that prevents blood from flowing backward from the left ventricle into the left atrium during heart contractions.

A degenerative cardiac disease where the mitral valve leaflets thicken and leak, allowing blood to back up into the left atrium.

A medical directive from Latin "nil per os," meaning nothing should be given by mouth (no food, treats, or water) for a specified period.

Involuntary, rhythmic oscillation of the eyeballs, either side-to-side, up-and-down, or rotatory, characteristic of vestibular disease.

A potent proton pump inhibitor (PPI) that suppresses gastric acid secretion to treat and prevent stomach ulcers and acid reflux.

A potent 5-HT3 receptor antagonist antiemetic that blocks peripheral and central serotonin nausea triggers.

The surgical removal of both testicles in a male animal to prevent reproduction, eliminate testicular tumors, and reduce androgen-driven behaviors.

A progressive, chronic degeneration of joint cartilage accompanied by joint inflammation, bone remodeling, and chronic pain.

Acute or chronic inflammation of the external ear canal, commonly complicated by secondary bacterial or yeast overgrowth.

The surgical removal of a female animal’s ovaries and uterus (ovariohysterectomy) or ovaries alone (ovariectomy) to prevent reproduction, heat cycles, and reproductive diseases.

A delicate, V-shaped organ nestled along the stomach and duodenum that has both digestive enzyme (exocrine) and hormone (endocrine) functions.

Inflammation of the pancreas that occurs when digestive enzymes activate prematurely inside the gland itself.

A surgical reconstructive procedure in male cats that removes the narrow penile urethra and creates a permanent, wider urethral opening to prevent urinary obstruction.

A progressive bacterial infection and inflammation of the supporting tissues of the teeth, leading to bone loss and tooth mobility.

Pinpoint, non-blanching red or purple hemorrhages in the skin and mucous membranes, signaling severe primary platelet disorders or vasculitis.

A long-acting barbiturate anticonvulsant that enhances GABA-mediated neuroinhibition to control epileptic seizures.

An inodilator that strengthens cardiac muscle contractions and dilates blood vessels to manage canine heart disease and failure.

The external cartilaginous projection of the ear that captures and funnels sound waves into the ear canal.

A quantitative count of circulating thrombocyte cell fragments essential for primary blood clotting and plugging vascular leaks.

A medical route abbreviation from Latin "per os," meaning that a medication or food must be administered orally by mouth.

Abnormally increased thirst and excessive water consumption.

The production and excretion of an abnormally large volume of urine.

Synthetic glucocorticoid steroid medications used to suppress inflammation, relieve allergic reactions, and manage autoimmune conditions.

A prescription abbreviation from Latin "pro re nata," directing a medication to be administered only as needed or as circumstances arise.

An unpleasant cutaneous sensation that provokes the desire to scratch, chew, lick, rub, or bite the skin.

A life-threatening bacterial infection and pus accumulation inside the uterus of intact female animals.

A clinical demeanor assessment indicating that an animal is conscious and responds to stimuli, but is calm, subdued, timid, or mildly lethargic.

A prescription abbreviation from Latin "quater in die," directing a medication to be administered four times a day, approximately every 6 hours.

A non-invasive diagnostic imaging modality using ionizing radiation to produce two-dimensional shadow projections of internal bones, lungs, and organs.

The passive, effortless expulsion of food or fluid from the esophagus or stomach without nausea or abdominal retching.

An endoscopic examination of the internal nasal passages and nasopharynx using rigid and flexible scopes.

The frequency of breaths taken by an animal, measured in breaths per minute (brpm).

A dynamic paired liver function test measuring serum bile acid concentrations before and 2 hours after a meal to evaluate hepatic vascular and parenchymal integrity.

A panel of blood biochemical tests that evaluates organ function, electrolytes, blood sugar, and metabolic status.

A quantitative serum blood test measuring glycated serum protein to evaluate average blood glucose concentrations over the preceding 2 to 3 weeks.

A veterinary prescription abbreviation from Latin "semel in die," directing a medication to be given once a day, every 24 hours.

The universal four-part clinical documentation structure used by veterinarians: Subjective, Objective, Assessment, and Plan.

A highly sensitive and specific immunoassay measuring canine pancreatic-specific lipase to diagnose or rule out acute pancreatitis.

A vascular lymphoid organ located in the cranial abdomen that filters blood, stores red blood cells, and mounts immune responses.

The surgical removal of the entire spleen, most commonly performed for bleeding splenic masses, trauma, or splenic torsion.

An aggressive, highly malignant vascular cancer that develops from the cells lining blood vessels, most commonly within the spleen.

An injection route abbreviation designating administration into the subcutaneous connective tissue layer beneath the skin.

The complex synovial joint connecting the femur, tibia, and patella, equivalent to the human knee joint.

Slow, painful, spasmodic, or straining urination, typically associated with lower urinary tract inflammation or obstruction.

Abnormal, loud, harsh respiratory sounds caused by turbulent airflow through narrowed or obstructed upper airways.

The surgical excision of a cutaneous, subcutaneous, or internal tissue mass with appropriate surgical margins to diagnose and treat tumors or cysts.

A sensitive renal biomarker produced by cellular metabolism and excreted by the kidneys, detecting kidney function loss earlier than traditional creatinine.

A sudden, temporary loss of consciousness and postural muscle tone followed by spontaneous, rapid recovery.

Incessant, painful, or ineffectual straining to defecate, typically caused by colonic or rectal irritation.

An emergency diagnostic and therapeutic procedure in which a needle or catheter is inserted through the chest wall into the pleural space to evacuate fluid or air.

An orthopedic surgical procedure that cuts and rotates the tibial plateau angle to eliminate cranial tibial thrust in dogs with cranial cruciate ligament (CCL) rupture.

A prescription abbreviation from Latin "ter in die," directing a medication to be administered three times a day, roughly every 8 hours.

An ophthalmic diagnostic procedure measuring intraocular pressure (IOP) in millimeters of mercury (mmHg) to screen for glaucoma and uveitis.

A quantitative serum immunoassay measuring the total concentration of circulating thyroxine (protein-bound and free T4).

The foundational triad of baseline vital signs recorded at every veterinary visit: rectal body temperature, pulse (heart rate), and respiratory rate.

The cartilaginous and membranous airway tube conducting air from the larynx to the bronchi of the lungs.

Involuntary, rhythmic, oscillatory muscle contractions causing shaking or shivering movements of part or all of the body.

The thin, semitransparent membrane separating the external ear canal from the middle ear cavity.

A minimally invasive diagnostic sampling procedure using real-time ultrasound guidance to direct a fine needle into deep internal organs or masses to harvest cells for cytology.

A quantitative laboratory test measuring the ratio of protein to creatinine in urine to diagnose and quantify renal glomerular protein loss.

The fibromuscular tubular conduit that conveys urine from the bladder neck to the outside of the body.

A physical, chemical, and microscopic examination of urine to evaluate kidney function and the lower urinary tract.

A distensible, muscular reservoir organ in the caudal abdomen that stores urine produced by the kidneys prior to urination.

The active, coordinated muscular ejection of stomach and upper intestinal contents through the mouth preceded by nausea and abdominal contractions.

A clinical medical chart abbreviation indicating that an anatomical structure, organ system, or laboratory test value falls completely within expected healthy parameters.