Differential white cell count Differential white cell count

The differential count provides the clinician with additional information upon which to interpret the laboratory findings.


Neutrophils

Cat
Juvenile cells (band cells) Normal range: 0-0.3 x 1 09/1 ( 0-3%)
Adult cells Normal range: 2.5-12.5 x 109/1 (35-75%)


Dog
Juvenile cells (band cells) Normal range: 0-0.3 x 1 09/1 ( 0-3%)
Adult cells Normal range: 2-11.5 :: 109/1 (60-70%)


In old animals high neutrophil counts (neutrophilia) are most often assowith inflammation, infection, the presence of exogenous or endocorticosteroids, stress and some forms of myeloproliferative disorder (e.g. lymphosarcoma).

Low neutrophil counts (neutropenia) are most often associated with bacterial, viral or protozoal infections, immune-mediated disorders, testineoplasia, uraemia and bone marrow disease.

Large numbers of juvenile band cells (a so-called 'shift to the left') is usually associated with the presence of infection (particularly septicaemia), inflammation or regenerative anaemia. It is also associated with toxand dirofilaria infections - both of which are rare in the UK.



Eosinophils
Cat Normal range: 0-0.5 x 109/1 (2-12%)
Dog Normal range: 0.1-1.25 x 109/1 (2-10%)


High eosinophil counts (eosinophilia) are associated with allergies, parasystemic eosinophilic syndrome in cats, hypoadrenocorticism, and infection, e.g. pyometra in cats and dogs.

Low eosinophil counts (eosinopenia) are associated with stress, hyperadrenocorticism and acute infection or inflammation. Eosinopenia has also been reported to occur in old dogs as part of the ageing process.



Basophils

Cat Normal range: Rare
Dog Normal range: Rare


Basophils are rarely seen on blood smears from cats and dogs. When present they are usually associated with allergic reactions. They are also seen associated with hyperlipoproteinaemia in dogs due to diabetes, liver disease, hyperadrenocorticism and nephrosis.



Monocytes
Cat Normal range: 0.1-0.85 x 109/1 (1-4%)
Dog Normal range: 0.15-1.35 x 109/1 (3-10%)


Only small numbers are usually seen in cat and dog blood. High monocyte counts are associated with hyperadrenocorticism, exogenous or endosteroids, and stress, inflammation, infection, immune-mediated tissue damage and malignancy. In fact any condition in which tissue damage is a feature.

Monocytosis is also reported to occur in old dogs as part of the ageing process.



Lymphocytes
Cat Normal range: 1.5-7 x 109/1 (20-55%)
Dog Normal range: 0.8-4.8 x 109/1 (12-30%)


In old animals high lymphocyte (lymphocytosis) counts are most likely associated with lymphocytic leukaemia or lymphosarcoma, stress, FIV infection, chronic immunestimulation or hypoadrenocorticism.

Hyperthyroid cats treated with methimazole or carbimazole may also develop lymphocytosis.

Low lymphocyte counts (lymphopenia) are usually associated with the effects of steroids (exogenous or endogenous), acute systemic infections, neoplasia of the lymphatic system, other lymphatic disease (including loss of lymph) and chronic renal failure. Atrophy of lymphatics is reported to occur in old age leading to lymphopenia.