Stress leukogram
Key concepts ·Also called: stress leucogram, steroid leukogram, cortisol pattern, stress response bloodwork
What it is
Cortisol released during illness, pain or stress — or given as steroid medication — moves four white cell types in a predictable direction: neutrophils and monocytes up, lymphocytes and eosinophils down. Vets learn it as a single recognisable signature.
Why it matters
The pattern is extremely common on veterinary panels and it is easy to misread the raised neutrophils as infection. Seeing all four changes together says the numbers are reflecting cortisol. It also works in reverse: an unwell dog that fails to show the pattern raises the question of Addison's disease, where cortisol cannot be produced.
What it can point to
- Any significant illness, pain or injury — cortisol rises with the body's stress response, not just with fear
- Steroid treatment, including skin, ear and eye preparations that are absorbed
- Cushing's disease in dogs
- The absence of this pattern in a sick dog is itself a clue, and points towards hypoadrenocorticism
Dogs and cats differ
Dogs show the steroid pattern more reliably and more strongly than cats, particularly the rise in monocytes. Cats have a separate and often confusing pattern of their own — an adrenaline response to being handled, which pushes both neutrophils and lymphocytes up, the opposite of the cortisol effect on lymphocytes.
Questions worth asking your vet
- Does the whole white cell picture fit a stress response rather than infection?
- Is my pet on any steroid medication, in any form?
- Would a repeat once my pet is settled at home look different?
Related terms
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