Issue Description Thrombocytosis is defined as increased number
of circulating platelets.
Causes Proposed causes of thrombocytosis include
anemia, iron deficiency, inflammatory cytokines, and paraneoplastic
production of thrombopoietin. Anemia and thrombocytopenia can be seen
in dogs with primary and metastatic hepatic hemangiosarcoma(HSA).
Prolonged coagulation times and clotting factor abnormalities have
been identified in dogs with hepatobiliary tumors, although these are
rarely clinically relevant.
Symptoms High platelet levels do not necessarily signal
any clinical problems, and are picked up on a routine full blood
count. However, it is important that a full medical history be
elicited to ensure that the increased platelet count is not due to a
secondary process. Often, it occurs in tandem with an inflammatory
disease, as the principal stimulants of platelet production (e.g.
thrombopoietin) are elevated in these clinical states as part of the
acute phase reaction.
High platelet counts can occur in
patients with polycythemia vera (high red blood cell counts), and is
an additional risk factor for complications.
platelet counts usually produce the most severe symptoms.
Diagnosis Laboratory tests might include: full blood
count, liver enzymes, renal function and erythrocyte sedimentation
rate. If the cause for the high platelet count remains unclear, bone
marrow biopsy is often undertaken, to differentiate whether the high
platelet count is reactive or essential.
Treatment Treatment for thrombocytosis depends on the
underlying condition that causes it. In most cases, the platelet count
will return to normal after the condition is resolved.