Pet Lab Test Glossary

An enzyme that lives inside liver cells and leaks into the blood when those cells are damaged. In dogs and cats it is the most liver-specific enzyme on a routine panel, which makes it the first number a vet looks at when liver trouble is suspected.

Also called: ALT, SGPT, GPT, alanine transaminase, liver enzyme

The main protein in blood, made only by the liver. It holds fluid inside the vessels and carries hormones, calcium and many drugs. A falling level is one of the more meaningful findings on a panel, because so few things cause it.

Also called: ALB, serum albumin

An enzyme produced by the bile system, bone, and — in dogs only — under the influence of steroids. It is one of the most frequently flagged values on a canine panel and one of the most over-interpreted, because so many harmless things raise it.

Also called: ALP, ALKP, AP, SAP, alk phos, alkaline phosphatase

An enzyme that helps digest starch, produced by the pancreas and several other tissues. It was once used to diagnose pancreatitis, but it is poorly specific in dogs and close to useless in cats, so it has largely been superseded.

Also called: AMYL, AMY, serum amylase

Not enough red blood cells, or not enough haemoglobin inside them, to carry oxygen properly. It is a finding rather than a diagnosis — the whole point of investigating it is to work out which of three quite different mechanisms is behind it.

Also called: anaemia, low red blood cells, pale gums, low haematocrit

An enzyme found in both liver cells and muscle, so a raised level has two possible homes. Read next to ALT and CK it becomes useful: liver-only patterns and muscle-only patterns look quite different once all three are on the page.

Also called: AST, SGOT, GOT, aspartate transaminase

A build-up of nitrogen waste products — urea and creatinine — in the blood. It is deliberately a neutral word: it says the waste is there without claiming the kidneys are at fault, because in a good number of cases they are not.

Also called: azotaemia, uraemia, high kidney values, raised urea and creatinine

The rarest white cell type in dogs and cats — many healthy animals have none in circulation at all. Because zero is normal, only a clearly raised count carries information, and it usually appears alongside raised eosinophils.

Also called: BASO, basophil count, basophilia

The sugar circulating in the bloodstream as the body's immediate fuel. In cats it is the value most often misread, because the stress of a car journey and a vet visit alone can push it into the diabetic range in a perfectly healthy animal.

Also called: GLU, blood sugar, glucose serum, hyperglycaemia, hypoglycaemia

A waste product made by the liver from digested protein and cleared by the kidneys. Because it is influenced by diet, hydration and gut bleeding as well as kidney function, it is never interpreted on its own.

Also called: BUN, urea, urea nitrogen, blood urea

A mineral needed for nerves, muscle contraction, clotting and bone. The total calcium on a standard panel is bound partly to albumin, so a low albumin drags it down artificially — which is why a genuinely abnormal result is confirmed with an ionised calcium test.

Also called: Ca, calcium, total calcium, ionised calcium, hypercalcaemia

An underactive thyroid gland in dogs, usually from gradual immune destruction of the gland. The signs creep up slowly — weight gain without overeating, low energy, a dull or thinning coat, and a dog that seeks out warm places.

Also called: underactive thyroid dog, hypothyroid dog, thyroid deficiency

A salt that normally moves in step with sodium and helps maintain the blood's acid-base balance. It earns attention when it drifts away from sodium — that mismatch, rather than the number itself, is what carries information.

Also called: Cl, chloride, serum chloride

A fat carried in the blood and used to build cell membranes and hormones. Unlike in people, it has almost nothing to do with heart disease in dogs and cats — here it is read as a clue to hormone problems, liver disease and diet.

Also called: CHOL, total cholesterol, blood fats

An enzyme that leaks out of muscle cells when they are damaged. It rises quickly and falls quickly, so a high value points to muscle injury within roughly the last day or two — including causes as mundane as an injection or a struggle at the clinic.

Also called: CK, CPK, creatine phosphokinase, muscle enzyme

A waste product from normal muscle activity that the kidneys filter out at a steady rate. It is the traditional workhorse of kidney testing, but it has a blind spot — it only starts to climb once about three-quarters of kidney function is already gone.

Also called: CREA, CRE, creatinine serum, kidney value

White cells specialised for parasites and allergic inflammation. In dogs and cats a raised count sends the search in two directions at once: worms, fleas and other parasites, or an allergic condition such as flea allergy or feline asthma.

Also called: EOS, eosinophil count, eosinophilia

A chemical test for blood in the stool that is present in amounts too small to see. It is most useful when a pet is anaemic with no obvious source of loss — but it reacts to meat in the diet, so the preparation matters as much as the result.

Also called: occult blood fecal, hidden blood in stool, FOB test

A microscope examination of a stool sample for worm eggs and parasite cysts, usually after floating them to the surface in a dense solution. A positive result names the parasite; a negative one is reassuring but never conclusive.

Also called: O&P, ova and parasites, fecal float, flotation, worm egg count

An overactive thyroid gland, and one of the most common hormonal diseases of cats over ten. The classic picture is a cat that eats enthusiastically and still loses weight, often with a fast heart rate and a scruffy coat.

Also called: overactive thyroid cat, hyperthyroid cat, thyrotoxicosis

The small fraction of thyroid hormone circulating unbound and available to tissues. Because it is less disturbed by unrelated illness than total T4, it is the test used to settle borderline cases — though in cats it has a false-positive problem of its own.

Also called: fT4, free thyroxine, fT4ed, free T4 by equilibrium dialysis

A protein-bound form of glucose that reflects the average blood sugar over the previous two to three weeks. It cuts straight through the biggest problem with a single glucose reading in cats — that stress can fake a diabetic result.

Also called: FRU, fructosamine serum, average blood glucose

An enzyme concentrated in the cells lining the bile ducts. It rises when bile flow is obstructed or the duct lining is inflamed, and it is most valuable when read side by side with ALP, because the two together separate causes that either alone cannot.

Also called: GGT, gamma GT, gamma-glutamyl transpeptidase

A test that detects proteins from the Giardia parasite rather than looking for the organism itself. It is considerably more sensitive than a standard stool float, which misses Giardia often enough that a dedicated test is worth running.

Also called: giardia, giardia ELISA, giardia antigen, giardiasis test

The family of blood proteins that includes antibodies and the proteins of inflammation. Unlike albumin, it goes up when the immune system is busy — so a high globulin is usually a sign that the body has been fighting something for a while.

Also called: GLOB, globulins, serum globulin

The share of blood made up of red cells, given as a percentage. Spin a tube of blood and the cells pack at the bottom — that packed column is what this number describes. It is the fastest, cheapest read on anaemia in practice.

Also called: HCT, PCV, packed cell volume, haematocrit

The iron-containing protein inside red cells that actually binds oxygen and carries it around the body. Measuring it tells your vet how much oxygen-carrying capacity your pet has, which is not always the same thing as how many red cells they have.

Also called: HGB, Hb, haemoglobin, blood pigment

Red blood cells breaking open and releasing their contents into the surrounding fluid. It happens for two very different reasons — inside the body as a disease, or inside the tube as a sample problem — and telling the two apart changes everything.

Also called: haemolysis, hemolysed sample, haemolysed, red cell breakdown

A fat-digesting enzyme largely produced by the pancreas. General lipase on a routine panel is a rough screen only; the specific pancreatic lipase tests, reported as cPL for dogs and fPL for cats, are far more reliable for diagnosing pancreatitis.

Also called: LIPA, LIP, pancreatic lipase, DGGR lipase, cPL, fPL

Fat suspended in a blood sample, giving it a milky appearance. It is most often just a sign that your pet ate before the blood draw, but it scatters light in the analyser and can make several unrelated results unreliable.

Also called: lipaemia, lipemic sample, milky blood, high blood fat

The immune cells that recognise specific threats and carry immune memory. Their count is unusually informative because it falls reliably under stress and steroids — a low value is one of the most common findings on a routine panel, and usually not a disease in itself.

Also called: LYM, LYMPH, lymphocyte count

A mineral involved in hundreds of enzyme reactions, in nerve conduction and in heart rhythm. It is not on every routine panel, but it becomes important in seriously ill patients — particularly when a low potassium refuses to correct.

Also called: Mg, magnesium, serum magnesium

How much oxygen-carrying pigment sits inside an average red cell, expressed as a weight per cell. It tends to track cell size closely, so it is usually read as a supporting number rather than a headline one.

Also called: MCH, mean cell hemoglobin

How densely packed with pigment the red cells are, rather than how much each one holds in total. Of the three red cell indices this is the one most often thrown off by the sample itself, so a flagged value is checked before it is believed.

Also called: MCHC, hemoglobin concentration

The average size of your pet's red blood cells. Size is a clue to cause: cells that are unusually large often mean the marrow is pumping out young replacements, while unusually small cells point towards a shortage of iron or an inherited quirk.

Also called: MCV, mean cell volume, red cell size

Large scavenging white cells that arrive after the first wave of neutrophils and clear up debris, dead cells and organisms that are hard to kill. A raised count usually signals that something inflammatory has been going on for a while.

Also called: MONO, monocyte count

The most numerous white cell in dogs and cats, and the first responder to bacterial infection and tissue damage. They also rise sharply with stress hormones, so a raised count does not automatically mean infection.

Also called: NEU, NEUT, segs, segmented neutrophils, bands, left shift

A mineral cleared by the kidneys and stored with calcium in bone. It rises as kidney function declines, and controlling it is one of the most effective things that can be done to slow chronic kidney disease in cats and dogs.

Also called: PHOS, P, phosphate, inorganic phosphorus

Tiny cell fragments that plug damaged blood vessels and start the clotting process. A genuinely low count risks bleeding, but a low number on a feline report is far more often a clumping artefact than a real problem.

Also called: PLT, thrombocytes, platelet count, thrombocytopenia

The main mineral inside cells, and the one with the most immediate effect on the heart. Both a high and a low value can be dangerous, and a markedly high potassium in a straining male cat is one of the true emergencies in small animal practice.

Also called: K, potassium, serum potassium, hyperkalaemia, hypokalaemia

The count of oxygen-carrying cells in a set volume of blood. It is the headline number for whether your pet is anaemic, and it moves for three broad reasons: blood lost, blood destroyed, or blood not being made fast enough in the bone marrow.

Also called: RBC, erythrocytes, red cell count, red blood cell count

A measure of how much the red cells vary in size from one another. Uniform cells give a low number; a mix of small old cells and large new ones gives a high one. It is often the earliest hint that a marrow has started responding.

Also called: RDW, anisocytosis, red cell size variation

The band of values printed beside each result, showing where most healthy animals fall. It is not a verdict on your pet — it is a statistical range built from a group of other animals, and healthy individuals routinely sit outside it.

Also called: reference interval, normal range, normal values, lab range

Young red blood cells released from the bone marrow before they are fully mature. Counting them answers the single most important question in an anaemic pet: is the marrow trying to fix the problem, or has it stopped responding?

Also called: RETIC, reticulocyte count, young red cells, regenerative response

A newer kidney marker that starts rising after roughly 40 per cent of kidney function is lost, rather than waiting for 75 per cent like creatinine. It is also unaffected by muscle mass, which makes it particularly useful in thin, older cats.

Also called: SDMA, symmetric dimethylarginine, early kidney marker

The main salt in the fluid outside your pet's cells, and the value that governs how water is distributed around the body. It is really a measure of water balance rather than of salt intake — a change usually means fluid has been lost or gained, not that the diet was too salty.

Also called: Na, sodium, serum sodium, hyponatraemia, hypernatraemia

A blood test that measures lipase coming specifically from the pancreas in dogs, rather than the mixture of lipases a general panel picks up. It is the most reliable single blood test for canine pancreatitis, though it is still read alongside the examination and imaging.

Also called: cPL, canine pancreatic lipase, Spec cPL, SNAP cPL, pancreatitis test dog

The feline version of the specific pancreatic lipase test. It matters more in cats than the canine equivalent does in dogs, because feline pancreatitis is easy to miss — affected cats often just go quiet and stop eating, with none of the dramatic signs dogs show.

Also called: fPL, feline pancreatic lipase, Spec fPL, SNAP fPL, pancreatitis test cat

A recognisable pattern in the white cell counts caused by the body's own cortisol rather than by any infection. Spotting it prevents a panel being read as evidence of disease when it is really evidence of a stressed, unwell, or steroid-treated animal.

Also called: stress leucogram, steroid leukogram, cortisol pattern, stress response bloodwork

The yellow pigment left over when old red blood cells are broken down. The liver normally clears it into bile, so a rise means one of three things: too many red cells are being destroyed, the liver cannot process it, or bile cannot get out.

Also called: TBIL, total bili, bilirubin total, jaundice, icterus

The combined weight of all protein circulating in the blood, made up mostly of albumin and globulin. The total alone rarely tells the story — which of the two halves moved, and in which direction, is where the meaning lies.

Also called: TP, total protein serum, serum protein

The main hormone the thyroid gland produces, measured as everything circulating in the blood — bound and free together. It is the starting point for two very different diseases: an overactive thyroid in older cats, and an underactive one in middle-aged dogs.

Also called: T4, TT4, total thyroxine, thyroid hormone

The main type of fat carried in blood after a meal. This is the value most sensitive to whether your pet was fasted — a sample taken a few hours after breakfast can look alarming and mean nothing at all.

Also called: TRIG, TG, blood fats, lipaemia

The pituitary gland's instruction to the thyroid to work harder. When the thyroid underperforms, the pituitary shouts louder and this value climbs — so a high TSH alongside a low T4 is the most convincing evidence of hypothyroidism in a dog.

Also called: TSH, cTSH, thyrotropin, thyroid stimulating hormone

The yellow bile pigment appearing in urine. What counts as normal differs sharply between the two species: a small amount in a dog's concentrated urine can be unremarkable, while any bilirubin in a cat's urine is abnormal and worth pursuing.

Also called: BIL urine, bilirubinuria, urine bile pigment

A dipstick reaction that turns positive for three different things: intact red cells, free haemoglobin from cells that have burst, and muscle pigment. Only the sediment examination under a microscope can tell you which of the three it actually was.

Also called: BLD, haematuria, hematuria, occult blood urine, haemoglobinuria

Sugar appearing in the urine, which healthy kidneys reabsorb completely. It shows up once blood sugar rises past a threshold the kidneys can no longer keep up with — so its presence usually means the blood glucose has been high, not just briefly elevated.

Also called: GLU urine, glucosuria, sugar in urine, glycosuria

Acidic by-products the body makes when it burns fat instead of sugar for energy. In a diabetic pet, finding them alongside glucose is a warning sign that the situation is tipping towards a genuine emergency.

Also called: KET, ketones, ketonuria, ketoacidosis

How acidic or alkaline your pet's urine is. Dogs and cats on a meat-based diet normally produce slightly acidic urine, and a persistent shift in either direction changes which type of bladder stone is likely to form.

Also called: pH, urine pH, urinary acidity

A dipstick check for protein leaking into the urine. It is a screening test only, and a genuinely unreliable one in cats — a positive result means the next step is a UPC ratio and a look at the sediment, not a diagnosis.

Also called: PRO, protein urine, proteinuria, urine dipstick protein

A number that measures protein loss properly by correcting for how concentrated the urine happens to be. It replaces the dipstick's guesswork and is the value used to decide whether protein-losing kidney disease needs treating.

Also called: UPC, UPCR, protein creatinine ratio, urine protein to creatinine

What a laboratory sees under the microscope after spinning down a urine sample: cells, crystals, casts and bacteria. It is the part of the urinalysis that explains the dipstick, and it frequently changes the interpretation of everything above it.

Also called: sediment, microscopic exam, urine microscopy, casts, crystals

A measure of how concentrated your pet's urine is. It is the value that turns a raised kidney result from a question into an answer — high blood urea with dilute urine means the kidneys, while high urea with concentrated urine usually means dehydration.

Also called: USG, specific gravity, SG, urine concentration, isosthenuria

The total count of immune cells in circulation, pooling five different types that do quite different jobs. On its own the total is a blunt instrument — the differential underneath it, showing which cell types moved, carries most of the meaning.

Also called: WBC, leukocytes, white cell count, white blood cell count