By The Pawline veterinary teamVeterinary-reviewed by Alastair Greenway, BVM&S MRCVS · 25 July 2026
Reference range · fL
814
Reference
8–14
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 — always read the value against that. Sign in to see your pet’s value on this strip.
MPV is the average size of the platelets. Larger, younger platelets can indicate the marrow is actively replacing them — a useful clue when the platelet count is low. In cats this figure is often unreliable because platelets clump so readily.
MPV (mean platelet volume) is the average size of the platelets — the cell fragments that form clots. It matters because platelet size is a rough marker of age: newly-made platelets released from the marrow are larger, and older circulating ones are smaller. So MPV offers a window on whether the marrow is actively producing fresh platelets, which is especially useful when trying to understand a low platelet count.
MPV is the average platelet size. Large, young platelets suggest the marrow is actively replacing them — but the figure is unreliable in cats.
Reading MPV with the platelet count
MPV is most informative read against the platelet count:
Low platelet count with a high MPV suggests the marrow is responding — pumping out large, young platelets to replace ones being lost or destroyed. This fits consumption or destruction (e.g. immune-mediated) rather than a marrow that has stopped producing.
Low platelet count with a low or normal MPV raises the concern that the marrow is not producing platelets (marrow suppression), because there is no wave of large young platelets.
So MPV helps distinguish a "using them up but making more" picture from a "not making enough" one — a genuinely useful fork when investigating thrombocytopenia.
Reading in isolation
On its own, and with a normal platelet count, MPV rarely carries a strong message. Its value is contextual, as a clue to platelet production when the count is abnormal.
In chronic disease
MPV is followed alongside the platelet count to track whether a low count is being met by a regenerative marrow response over time — a helpful sign in immune-mediated or consumptive thrombocytopenia under treatment. It is one supporting piece of the platelet picture rather than a stand-alone marker.
Cat vs dog
Here the species difference is a major caveat: in cats, MPV (and the platelet count itself) is frequently unreliable because feline platelets clump so readily and are naturally large and variable, which distorts the analyser's measurement. So a feline MPV is interpreted with real caution and often confirmed on a blood smear. In dogs it is more dependable, though a smear still adds context. In both, MPV is read with the platelet count, not alone.
How it's measured
MPV is measured by the analyser as part of the platelet analysis in the CBC, reported in femtolitres (fL). Because platelet clumping (especially in cats) distorts it, a blood smear is used to corroborate the platelet picture. Read the value against your own report's range.
What to do next
MPV is most useful when the platelet count is low — a high MPV suggesting an actively responding marrow (consumption or destruction), a low-normal MPV raising the concern of reduced production. In cats especially, the figure is confirmed on a smear because of clumping. As a contextual index, it is interpreted together with the platelet count rather than on its own.
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.
