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===Artefactual or spurious thrombocytopaenia===
 
===Artefactual or spurious thrombocytopaenia===
 
*'''Cavalier King Charles spaniels''' have a genetic abnormality which produces a small number of giant platelets (macrothrombocytes) in the circulation with a corresponding reduction in free platelets; they do not suffer from bleeding disorders as they maintain a similar total platelet mass as do dogs of other breeds. Automated blood counts will include the macrothrombocytes in the white or red cell count and the apparent thrombocytopenia will be exaggerated.  
 
*'''Cavalier King Charles spaniels''' have a genetic abnormality which produces a small number of giant platelets (macrothrombocytes) in the circulation with a corresponding reduction in free platelets; they do not suffer from bleeding disorders as they maintain a similar total platelet mass as do dogs of other breeds. Automated blood counts will include the macrothrombocytes in the white or red cell count and the apparent thrombocytopenia will be exaggerated.  
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*'''Greyhounds''' and other sight hounds frequently have platelet counts at the lowest end of the reference range (as well as increased haematocrit, mild neutropaenia and reduced T4 levels) but this is a normal finding for this breed.
 
*If venepuncture is traumatic (using small viens with excessive suction or patient agitation) '''platelet clumps''' may form and these will not be counted by automated machines.  The presence of clumps can be investigated by making a blood smear and examining the feathered edge for large agglomerations of platelets. Time, temperature and contact with glass can also cause clumping of platelets once the sample has been taken.
 
*If venepuncture is traumatic (using small viens with excessive suction or patient agitation) '''platelet clumps''' may form and these will not be counted by automated machines.  The presence of clumps can be investigated by making a blood smear and examining the feathered edge for large agglomerations of platelets. Time, temperature and contact with glass can also cause clumping of platelets once the sample has been taken.
  
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