By The Pawline veterinary teamVeterinary-reviewed by Alastair Greenway, BVM&S MRCVS · 25 July 2026
Reference range · 10³/µL
311.5
Reference
3–11.5
Direction
Both unusually high and low values carry meaning.
This is the conventional reference interval. Your pet’s own report may print a slightly different range, so always read the value against that. Sign in to see your pet’s value on this strip.
Neutrophils are the immune system's front-line responders to infection and inflammation, and they are usually the largest part of the white cell count. Shifts here — up or down — help characterise what the total count is reacting to, and a supporting detail called a 'left shift' adds important context.
Neutrophils are the shock troops of the immune system: abundant, fast-moving cells that rush to sites of bacterial infection and inflammation to engulf and destroy invaders. Because they usually make up the biggest share of the white cell count, changes in neutrophils often drive changes in the total — which is why they are the first part of the differential to read.
Neutrophils are the front-line responders that engulf bacteria. Their number, and how mature they are, characterise the body's response.
Two things matter about neutrophils: how many there are, and how mature they are.
Reading a high result
A raised neutrophil count (neutrophilia) is one of the commonest blood findings and typically reflects:
Inflammation or bacterial infection, the classic driver — the marrow ramps up production and dispatches cells to the fight.
Stress and steroids, which shift stored neutrophils into circulation (part of the "stress leukogram"), raising the count without infection.
Excitement/adrenaline, a brief rise, especially in cats and young animals.
The vital piece of extra information is the left shift: the appearance of immature neutrophils (band cells) in the blood. Their presence means the marrow is working so hard it is releasing cells early — a strong indicator of genuine, active inflammation or infection rather than a mere stress response. So a neutrophilia with a left shift reads very differently from the same count without one.
Reading a low result
A low neutrophil count (neutropenia) can be important because neutrophils are a first line of defence — too few, and infection risk rises. Causes include overwhelming infection consuming them faster than they can be made, bone-marrow suppression (some viruses, drugs, or marrow disease), and certain immune processes. A marked neutropenia, especially with a sick pet, usually prompts prompt investigation and precautions against infection.
In chronic disease
Followed over time, the neutrophil count tracks the intensity of an inflammatory or infectious process and the marrow's response to it, and monitors treatments that can suppress the marrow. A falling neutrophilia (and a resolving left shift) tracks recovery; a rising count or a new left shift flags a process that is escalating.
Cat vs dog
Neutrophils behave similarly in both species, with slightly different reference ranges. The stress and excitement responses can be pronounced in cats, so a modestly raised neutrophil count in a stressed cat is interpreted with that in mind, and the presence or absence of a left shift again helps separate true inflammation from a stress effect. In both species, the neutrophil count is always read together with the rest of the differential.
How it's measured
Neutrophils are reported both as a percentage and as an absolute count (×10³/µL) within the CBC differential; the absolute number is the more meaningful figure. A blood smear allows the immature band cells of a left shift to be identified and counted. Read the value against your own report's ranges.
What to do next
A raised neutrophil count is read in the light of the clinical picture, whether stress could explain it, and — crucially — whether a left shift is present. A neutrophilia with a left shift in an unwell pet points towards active infection or inflammation to pursue; a low neutrophil count is a reason to look for a marrow or consumption problem and to guard against infection. Your vet weighs these together, not the count alone.
Reference ranges reflect conventional laboratory intervals. Always interpret against your own lab's printed range and your veterinary surgeon's judgement. A brighter optimal band is shown only where a published guideline defines one, and it is cited.
This page is educational and is not a diagnosis. Lab results are interpreted in the full clinical context by your veterinary surgeon; a single value rarely tells the whole story.
