Glossary of Terms
We thought it might be helpful to de-mystify some of the medical terminology we use on a day-to-day basis. The list below is by no means exhaustive; please do not hesitate to interrupt us if we use confusing language as we are only too happy to explain any unfamiliar terms!
ACIDOSIS – disease resulting from a failure to regulate blood acidity within normal ranges; usually due to severe kidney or metabolic disease. Clinical signs: muscle twitching, involuntary movement, cardiac arrhythmias, disorientation, coma
ABDOMEN – the compartment in the body below the diaphragm that contains the liver, pancreas, intestines, stomach, kidneys, reproductive organs and urinary bladder.
ADENOPATHY – enlargement of the glands especially the lymph nodes,i.e. lymphadenopathy.
ADDISON’S DISEASE – A disease of the adrenal glands that results in deficiency of the body’s natural steroid, cortisol, with concurrent failure to regulate electrolyte concentrations. Clinical signs: vomiting, abdominal pain, weakness, collapse
ADENOMA – benign tumour derived from structures in the skin or glands within the body. Adenocarcinomas however, are malignant, and much more difficult to treat.
ADRENAL GLANDS – paired glands, located near the kidneys in the abdomen. They produce several important hormones e.g. cortisol as well as regulating the body’s electrolyte levels.
AETIOLOGY- the underlying cause of disease.
ANAL FURUNCULOSIS – immune-mediated inflammation of the skin surrounding the anus.
ANAL SACS/ ANAL GLANDS – a pair of small sacs situated either side of the anus that are lined with glandular tissue. These glands secrete a pungent fluid into the sacs that passes along narrow ducts to empty onto the faeces for scent marking. Narrowing of the ducts and/ or infection of the sacs may necessitate their removal – analsacculectomy.
ANCONEAL PROCESS – projection of the ulna within the elbow joint. Sometimes a condition termed ‘Ununited anconeal process’ is occasionally seen in young dogs, and is indicative of Elbow Dysplasia (see below).
ANAEMIA – a decrease in numbers of red blood cells within the circulation, as a result of either severe or chronic bleeding, bone marrow disease, or the inappropriate destruction of red blood cells (usually by a fault in the immune system). Dietary causes are extremely rare.
ANAESTHESIA – strictly speaking, this means a loss of feeling or sensation; but practically, general anaesthesia is a drug-induced coma to allow surgery to be performed without patients feeling any pain, or to stop patients moving during diagnostic testing that requires prolonged periods of immobility such as x-rays or MRI. Local anaesthesia is the numbing of an area or region of the body to allow minor surgery in the conscious patient.
ANNULUS FIBROSUS – Circular ligament around the intervertebral disc which provides structural support to the joint and contains the nucleus pulposus within the centre of the disc.
ANTIBIOTIC – a drug that destroys or inhibits the growth of bacteria or other microorganisms.
ARACHNOID CYST – see subarachnoid cyst
ARTHRODESIS – surgical procedure which results in the bony fusion of a joint – often performed to reduce pain associated with degenerative joint disease, or to manage a badly broken bone or dislocation.
ARRYTHMIA – an abnormal heart rate or rhythm; may require investigation using an ECG
ATAXIA - loss of balance or coordinated voluntary movement. This is usually indicative of a lesion(s) within the central nervous system.
BENIGN - not malignant. Disease process (usually pertaining to tumours) with low propensity for recurrence or distant spread.
CASTRATION- surgical removal of the testicles. Usually performed to prevent unwanted pregnancy, but may also be used as part of a treatment plan for dominance aggression, vagrancy or to manage disease of the testes, anal adenomas or prostate gland.
CAUDAL – towards the tail of the animal.
CARCINOMA – a malignant tumour originating from epithelial cells (eg. tumours arising from mammary gland, uterus, intestine and skin).
CARDIAC – pertaining to the heart.
CENTRAL NERVOUS SYSTEM ‘CNS’ – the brain and spinal cord.
CEREBROSPINAL FLUID (CSF) – clear, colourless, watery fluid contained within the dura that surrounds the central nervous system(CNS), and acts as a shock absorber. Certain diseases of the CNS may be detected by sampling the fluid via a spinal tap.
CERVICAL SPONDYLOMYELOPATHY – aka ‘wobblers’. Compression of the cervical spinal cord caused by malformation or instability of the vertebra. Common in large and giant breeds especially Great Danes, Rottweilers and Dobermanns. Clinical signs: ataxia of the hind limbs and occasionally forelimbs, wide-based stance, proprioceptive deficits and possible neck pain.
CHEMOTHERAPY – literally, the treatment of disease with drugs. However, more commonly used to denote treatment of cancer, or immune mediated disease with immunosuppressive drugs.
CHIARI MALFORMATION – an hereditary, congenital, shortening of the skull seen in Cavalier King Charles Spaniels, resulting in herniation of the back of the brain down the spine, which can lead to syringomyelia.
CHONDRODYSTROPHOID BREEDS – e.g. Dachshunds, Bull-dogs, Bassett Hounds, Shih Tzus, etc. A genetic subset with abnormal cartilage development resulting in dwarfism – bowing of the long-bones to give the characteristic conformation. A side-effect of this abnormality is a predisposition to early degeneration of the nucleus pulposus resulting in a high rate of disc-related disease within such breeds.
CHRONIC DEGENERATIVE RADICULOMYELOPATHY (CDRM)- aka Degenerative Myelopathy. A progressive, non-painful degenerative disease of the spinal cord, commonly seen in German Shepherd Dogs and other large breeds. Cause unknown. Clinical signs: paraparesis, truncal ataxia
CLONIC – involuntary jerking movements affecting the muscles
COMMINUTED FRACTURE – a break in the bone resulting in more than two fragments.
CONGENTIAL – a developmental defect, present at or existing from the time of birth.
CONTUSION - bruising of the tissues. Of increased significance within the central nervous system, as nervous tissues are constrained within a fixed space; swelling may occur as a consequence of contusion, resulting in pressure building up and damage to the CNS.
CORTICOSTEROIDS – aka ‘cortisone’ – a group of synthetic drugs that has a wide variety of uses, particularly in the management of inflammatory and immune mediated conditions.
CORTISOL - a hormone produced by the adrenal glands; acts as the body’s own, naturally occurring corticosteroid.
CRANIAL – towards the head of the animal
CRUCIATE LIGAMENTS – cranial and caudal ligaments which cross within the stifle joint to stabilise the knee. The cranial cruciate ligament commonly fails and causes instability with secondary osteoarthritis and possible meniscal damage, necessitating surgical repair – see TPLO/ TTA.
CT (COMPUTED TOMOGRAPHY) – a 3D xray study to rapidly image bones and soft tissues. Particularly useful for studying the chest and complex fractures.
CUSHING’S DISEASE – a disease of the adrenal or pituitary glands resulting in excessive levels of cortisol in the body. Clinical signs: excessive thirst, appetite, coat changes, muscle loss, leading to a pot-bellied appearance. Long-term liver disease.
DECOMPRESSIVE SURGERY – direct removal of masses (usually degenerate disc material, tumours, haematomas or bone fragments) from within the spinal canal to relieve pressure on the spinal cord and nerve roots. High-risk surgery, so usually reserved for paralysed patients or those with intractable pain.
DEGENERATIVE JOINT DISEASE – aka ‘DJD’ – irreversible, wear-and-tear erosion of the contact surfaces within a joint. The underlying cause is usually previous injury, repetitive trauma or abnormal development resulting in incongruency. Osteoarthritis is the inevitable consequence of DJD.
DEGENERATIVE MYELOPATHY – see chronic degenerative radiculomyelopathy (CDRM).
DEEP PAIN SENSATION – the ability of a patient to perceive and therefore respond in a conscious manner (look round/ bite/ cry out) to a painful stimulus caudal to a lesion in the central nervous system. Of vital importance in assessing the likelihood of spinal cord recovery after injury.
DIAPHRAGM – a muscular membrane which separates the abdomen from the thorax which has a central role in normal breathing. Sometimes will rupture after blunt trauma (e.g. road traffic accident) resulting in respiratory difficulties, necessitating surgical repair.
DIABETES MELLITUS aka ‘DIABETES’ – a failure of the pancreas to produce sufficient insulin. Results in abnormally high levels of sugar in the blood which leads to long-term health issues if not managed correctly.
DORSAL - towards the upper surface/ back. Synonymous with the term ‘posterior’ in man.
DURA (MATER) –protective fibrous layer of the meninges covering thebrain and spinal cord.
ECHOGRAPHY- see ultrasonography
ECG or Electrocardiogram – a recording of the electrical impulses generated by the heart, often used to investigate abnormal rates and rhythms.
EFFUSION- an abnormal build-up of fluid into a part of the body, e.g. skeletal joint, abdomen, chest cavity.
ELBOW DYSPLASIA – abnormal development of the elbow joint during the rapid growth phase seen in puppies less than 12 months old – results in a range of conditions, all of which lead to degenerative joint disease.
ELECTROLYTES – salts found within the fluid both inside and surrounding the cells of the tissues of the body. Their concentrations are regulated closely by several hormones, to enable normal functioning of the cells.
EMBOLISM – sudden blocking of an artery by a clot of foreign material such as a blood clot, fat globule, air bubble, or piece of abnormal tissue (e.g. degenerated intervertebral disc or clump of bacteria). Results in ischaemia/ infarction of the tissue supplied by that vessel (e.g. spinal fibrocartilagenous embolism, FCE).
ENCEPHALOPATHY – any degenerative disease of the brain.
ENDOSCOPY – the visual examination of the internal structures of the body using a specialised camera or endoscope.
EPILEPSY – transient and intermittent seizure activity resulting from abnormal electrical activity within the forebrain. Idiopathic forms can be inherited in many purebred dogs where seizures typically start at a young age (1-3 years).
EPITHELIAL – the cellular covering of internal and external body surfaces including the lining of vessels and other small cavities.
FENESTRATIONS – surgical technique with the aim of relieving the pressure inside degenerate intervertebral discs to prevent progression of neurological signs. Relatively low risk surgery, as compared to decompressive surgery, so often used for patients with relatively mild signs, such as recurrent spinal pain, or mild weakness/ proprioceptive deficits.
FIBROCARTILAGINOUS EMBOLISM, ‘FCE’) – extrusion of degenerate intervertebral disc material into spinal blood vessels, which results in ischaemic myelopathy. Clinical signs: acute paresis or paralysis
FRACTURE - any break in a bone, irrespective of severity.
GASTROINTESTINAL – pertaining to the stomach and guts
GERIATRIC – older patients; normally pertaining to cats and small dogs over the age of eight and large breed dogs over the age of six.
HAEMATOMA - blood clot.
HAEMOLYTIC ANAEMIA – Rapid and spontaneous destruction of the red blood cells caused by an imbalance in the immune response.
HAEMORRHAGE – bleeding
HANSEN TYPE I DISC EXTRUSION – rupture of the external ligament of the disc (annulus) with extrusion of the nucleus pulposus into the vertebral canal to compress the spinal cord and/ or its associated nerve roots. Commonly seen in the neck and thoracolumbar regions of the spine in young adult chondrodystrophoid breeds (e.g. Dachshunds, Pekingese and Shih Tzus). Clinical signs: spinal pain, progressive neurological deficits, e.g. paraparesis, paraplegia, tetraparesis.
HANSEN TYPE II DISC PROTRUSIONS – occur in nonchondrodystrophoid breeds. Chronic instability of an intervertebral joint causes partial rupture of the annulus fibres, resulting in deformation and compression of the spinal cord and/or nerve roots. Usually seen in the lumbar spine in geriatric large-breed dogs. Clinical signs: spinal pain, progressive neurological deficits, e.g. paraparesis, paraplegia.
HEPATIC – pertaining to the liver.
HERNIA – the abnormal protrusion of an organ or part of an organ through weakened structures normally constraining it.
HORMONE - a ‘chemical messenger’ produced by specialised glands within the body, carried to their target organ via the blood stream. They have a wide variety of functions, but most regulate growth and development or maintain the level of metabolites in the tissues within specific ranges.
HYPOTHYROIDISM – an underactive thyroid gland, normally a condition affecting dogs. Clinical signs: lethargy, weight gain, neurological deficits, cold intolerance.
HYPERTHYROIDISM – an overactive thyroid gland, normally a condition affecting cats. Clinical signs: weight loss, ravenous appetite, abnormally rapid heart rate.
ICTERUS – jaundice, or yellowing of the mucous membranes within the eye, the sclera (whites of the eye) or skin. Usually indicative of serious liver disease or haemolytic anaemia.
IDIOPATHIC - no known cause identified.
IMMUNE SYSTEM – the set of organs (mainly the bone marrow and spleen) responsible for producing specific cells which provide the body’s defences against infection and cancer.
IMMUNE MEDIATED disease – caused by a malfunction in the regulation of the body’s response to infection, resulting in healthy cells in the body being attacked by the immune system.
IMMUNOSUPRESSIVE THERAPY – treatment designed to reduce the amount of immune response generated by the body. Often used for immune-mediated disease and cancer.
INFARCTION - localised, irreversible damage to the tissues of an organ from a sudden blockage of the blood supply.
INSULIN - a hormone produced by the pancreas responsible for the regulation of blood sugar. Insulin deficiency results in diabetes mellitus, whereas accidental overdose of therapeutic insulin can cause a diabetic coma.
INTERVERTEBRAL DISC – fibrous joint between the vertebrae, located just beneath the spinal cord. May causes back pain, weakness or paralysis if becomes diseased.
ISCHAEMIA – deficiency of blood in a localised area of tissue, due to physical or functional constriction of a blood vessel; may result in reversible or irreversible damage to an organ.
JAUNDICE – yellowing of the mucous membranes within the eye, the sclera (whites of the eye) or skin. Usually indicative of serious liver disease or haemolytic anaemia.
LAMINECTOMY – a form of decompressive surgery where the spinal canal is opened over the top (dorsal laminectomy) or the side (hemilaminectomy).
LATERAL – positioned towards the side (ie. away from the midline).
LOWER MOTOR NEURON – nerve cells providing the final link between the central nervous system and the effector organ, e.g. muscle. (c.f. upper motor neuron). Clinical signs: loss of motor function, reduced muscle tone, loss of segmental spinal reflexes. Bladder may show flaccid paralysis with incontinence.
LUXATION - joint dislocation.
MALACIA - structural change (softening) within the tissues. Myelomalacia pertains to changes occurring within the central nervous system and may indicate severe, irreversible damage.
MALIGNANT – tending to become progressively worse. Often pertaining to tumours which have a tendency to recur or spread to distant areas of the body.
MEDIAL – positioned towards the midline.
MENINGOENCEPHALOMYELITIS – Generalised or multifocal inflammation of the central nervous system. Often treated symptomatically if no underlying cause identified.
MENISCUS - paired, crescent-shaped cartilage within the knee joint. Often becomes damaged after the cranial cruciate ligament fails.
METABOLIC DISEASE – secondary illness occurring as a result of a malfunction of one or more organs of the body to upset the balance of salts and other chemicals in the blood.
METASTASIS - malignant spread of a tumour (usually via the blood stream or lymphatics) to distant sites within the body, not directly connected to the original lump.
MRI (MAGNETIC RESONANCE IMAGING) – a form of advanced imaging used to view slices through the body in any plane of orientation. Has the ability to view inside bony structures, so very helpful in imaging the central nervous system, pelvis and nasal cavity, but useful in assessing tissue abnormalities elsewhere. Acquiring the images takes several minutes, so it is usually necessary to immobilise the patient with general anaesthesia.
MUCOUS MEMBRANES – non-hairy areas of specialised skin possessing abundant blood supply, located at the junction of the orifices; eye, mouth, genitalia, etc – very useful for visually assessing blood oxygen concentration and other metabolic disease.
MYELITIS – inflammation of the spinal cord substance.
MYELOGRAM - a form of X-ray study, involving the injection of a dye into the cerebrospinal fluid that surrounds the central nervous system. It may be useful in assessing abnormalities of the spinal cord, but is inherently risky and has largely been superseded by the increased availability of MRI.
MYELOPATHY – any functional disturbance or pathological change in the spinal cord.
MYOSITIS – inflammation of the muscles.
NEUROLOGICAL – pertaining to the (central) nervous system.
NEUTER - to desex an animal by castration or ovariohysterectomy (spay)
NEOPLASIA – uncontrolled growth of tissues. The term ‘cancer’ is often used to describe malignant tumours that are difficult to treat, but neoplasia also encompasses benign growths as well.
NUCLEUS PULPOSUS – the centre of an intervertebral disc. Normally contains water to provide cushioning, but may degenerate and harden before damaging the surrounding annulus with the potential to cause back/ neck pain, or paresis/ paralysis.
NSAIDs (NON-STEROIDAL ANTI-INFLAMMATORY DRUGS) – a group of drugs that have anti-inflammatory, painkilling and anti–pyretic (see pyrexia) actions. Very occasionally, side-effects (including gastrointestinal irritation and kidney problems) necessitate cessation of therapy and consideration of alternative drugs.
NYSTAGMUS – periodic rhythmic involuntary movements of both eyeballs in unison, normally associated with neurological or ear disease.
OMENTUM – a lace like membrane found within the abdomen. Often transplanted to distant sites in the body to fight infection/ drain cavities.
OSTEOARTHRITIS – inflamed and painful joints as a result of ‘wear-and-tear’ type degenerative joint disease.
OSTEOCHONDROSIS – abnormal development of cartilage within the joints, particularly the shoulders, elbows, stifles (knees) and hocks (ankles) of young, large-breed dogs. Sometimes results in a flap of dead cartilage developing (osteochondritis dissecans, OCD), which may require removal surgically, but all forms of osteochondrosis inevitably lead to osteoarthritis of the affected joint.
OVARIOHYSTERECTOMY – surgical removal of the ovaries and uterus as a means of preventing pregnancy and ovarian cyclicity
PANCREAS – a gland located in the abdomen that releases insulin into the blood stream and digestive enzymes directly into the gut.
PANCREATITIS – inflammation of the pancreas. Clinical signs: pain in the abdomen, vomiting
PARESIS – weakness of one or more limbs; paraparesis involves both hindlimbs, tetraparesis involves all limbs. Affected animals may be unable to stand, but must still show evidence of voluntary movement in the affected limbs.
PERINEUM - the region of the body that surrounds the anus. Weakening of the underlying muscles can result in herniation of abdominal organs through the pelvis resulting in swelling around the back-end and potential inability to empty the bladder – a situation which may constitute an emergency.
PITUITARY GLAND – a small gland located at the base of the brain which controls the release of many hormones in the body including the thyroid hormone and cortisol. May have a role to play in several illnesses such as Cushings disease, rare forms of diabetes and grow disturbances.
PLATELET – a small blood cell that is involved in clotting.
PLEURA – a double membrane lining the thorax and lungs.
PLEURAL EFFUSION – accumulation of fluid between the two layers of pleura resulting in compression of the lungs and difficulty breathing.
PLEGIA – complete paralysis of one or more limbs. Monoplegia – loss of voluntary movement in one limb. Paraplegia – loss of voluntary movement in both hindlimbs, tetraplegia – loss of voluntary movement in all four limbs. Plegia is usually seen as a result of severe lesions within the spinal canal (e.g. disc disease, tumours, haemorrhage) which have interrupted the nerve pathways between the brain and the muscles of the limbs.
POLYP – Any mass/growth protruding from a mucous membrane, attached either by a thin stalk (pedunculated) or by a broad base (sessile). Usually an overgrowth of normal tissue or benign tumour but occasionally becoming malignant.
PROPRIOCEPTIVE DEFICITS – the loss a patient’s ability to accurately detect the positioning of their limbs in space. Despite being non-specific in terms of cause, such deficits are important to recognise as they are often a precursor to more serious neurological impairment.
PULMONARY – pertaining to the lungs.
PYOMETRA - closed infection of the womb. Can rapidly progress to blood poisoning and serious illness if not detected early. Clinical signs: excessive thirst, dullness, vomiting. May or may not show vulval discharge.
PYREXIA - abnormally elevated body temperature. Often indicative of pain, significant inflammation or infection.
RADIOGRAPHY – a form of imaging of the tissues of the body by using exposure of film that is specially sensitized to x-rays. Particularily useful for assessing diseases of the bones (e.g. fractures, infection, cancer).
RADIOTHERAPY- treatment of disease (usually cancer) by means of radiation. Availability of the necessary equipment is poor, requiring patients travel significant distances for treatment.
RED BLOOD CELLS aka erythrocytes – the cells in the blood that carry oxygen around the body.
RENAL - pertaining to the kidneys.
SARCOMA - malignant tumour derived from connective tissues, including bone, cartilage, muscle, fat, blood vessels and lymphoid tissue.
SEIZURE – Abnormal forebrain activity resulting in sudden stereotypical movements of an isolated area of the body (partial seizure) or alternating muscle rigidity and jerking affecting the whole body (tonic-clonic seizure).
SEROMA - a focal collection of tissue-fluid under the skin. These are a relatively common postoperative complication, but usually managed without further intervention, as they normally disperse naturally over a week or two.
SPAY aka ovariohysterectomy – surgical removal of the ovaries and uterus (womb). Used to prevent unwanted pregnancy or control/ prevent diseases of the womb. Spaying also has a protective effect against mammary (breast) cancer.
SPINAL CANAL – hollow tube within the spinal column, containing the spinal cord and its associated nerve roots and blood vessels. The canal lies immediately over the intervertebral discs, and the structures contained within are therefore susceptible to compression as a consequence of disc disease.
STIFLE - the knee joint.
SUBARACHNOID CYST – congenital malformation of the membranes surrounding the spine which results in build up of fluid and pressure on the spine. Clinical signs: progressive weakness and loss of co-ordination of the limbs, especially in young patients.
SUTURE - surgical material used to stich a wound together. Normally requires removal from the skin 7-14 days after an operation.
SYRINGOMYELIA – aka syringohydromyelia. Progressive cavitation of the spinal cord secondary to Chiari Malformation or scarring/ tumours within the central nervous system. A painful condition with variable signs. Diagnosis requires MRI.
THORAX – the chest cavity, containing the lungs, heart and major blood vessels.
THYROID GLAND – small, paired glands sited either side of the larynx (voice box). Control the metabolic rate. Often overactive in elderly cats (hyperthyroidism) and underactive in dogs (hypothyroid).
TIGHTROPE – a novel form of cranial cruciate ligament repair involving the implantation of a special suture, anchored via bone-tunnels to stabilise the stifle.
TONIC – muscle rigidity
TPLO - Tibial Plateau Levelling Osteotomy. A surgical procedure to modify the weightbearing forces through the cranial cruciate deficient stifle.
TTA - Tibial Tuberosity Advancement. An evolution of the TPLO – modifies the weightbearing forces within the stifle with a lower rate of serious complications as compared to its predecessor.
ULTRASONOGRAPHY – a form of imaging of the tissues of the body using the application of sonar. Rapid diagnosis possible in the conscious patient but cannot penetrate bone or air-filled structures, so mainly used for examining abdominal organs and tendons.
UPPER MOTOR NEURON – nerve-cells within the central nervous system which conduct messages to lower motor neurons. They have an inhibitory effect, so lesions that affect upper motor neurons usually result in exaggerated segmental spinal reflexes. Clinical signs: loss of motor function with increased muscle tone. Bladder often retains urine, leading to overflow incontinence.
VENTRAL - towards the underside of the body.
VENTRAL SLOT – a form of decompressive surgery where the spinal canal is opened from beneath via a slot cut though the vertebra. This technique is usually performed to treat severe disc disease in the neck.
WHITE BLOOD CELLS aka leucocytes – the cells in the blood responsible for fighting infection
WOBBLERS aka ‘Cervical Spondylomyelopathy’ – malformation of the joints of the cervical spine seen in certain breeds, especially Dobermann Pinschers, Great Danes and Rottweilers. clinical signs: Progressive weakness of all four limbs often starting in mature patients which results in eventual collapse.
