Platelet indices in dogs with thrombocytopenia and dogs with normal platelet counts

Abstract

It is well known that thrombocytopenia is the most commonly acquired haemostatic disorder in dogs and can be potentially life-threatening. With the use of automated analysers, platelet indices such as Mean Platelet Volume (MPV), Platelet Distribution Width (PDW), and Platelet Large Cell Ratio (P-LCR), became routinely available, allowing data comparison and error checks which results in a more effective quality control. The aim of this study was to evaluate the pattern of platelet indices (MPV, PDW and P-LCR) in dogs with thrombocytopenia and with normal platelet values. The results of 351 CBCs processed in an automated veterinary haematology counter Sysmex^® pocH-100iV Diff were analysed. Two groups of dogs were established, those with thrombocytopenia (45) and those with normal platelet counts (306). Thrombocytopenic dogs were subdivided in dogs with less than 150,000 platelets/μL of blood (19/42,2%) and dogs with over 150,000 platelets /μL of blood (26/ 57,8%). Mean values of PDW and P-LCR indices in thrombocytopenic animals were significantly higher than the mean values of animals with normal platelet counts. There was no significant difference in any of the indices in either group of thrombocytopenic dogs. Macroplatelets were present in the blood smears of thrombocytopenic dogs. Results suggested increased thrombopoiesis and release of different sized platelets. It was concluded that both PDW and P-LCR increase in dogs with thrombocytopenia and they are more sensitive than MPV. P-LCR is also important in thrombocytopenic dogs, especially when associated to the presence of large platelets in blood smears.