Physiological adjustments of haematological profile during the last trimester of pregnancy and the early post partum period in mares

The aim of the study was to assess changes in some haematological parameters of periparturient mares from the last three months of pregnancy until the third week after foaling. The study was carried out on 15 healthy pregnant mares (Group A) and 7 healthy non-pregnant non-lactating mares (Group B). Blood samples were collected by jugular venipuncture into EDTA tubes and tested for Haematocrit (Hct), Red Blood Cell (RBC), Haemoglobin (Hb), Platelets (Plt) and White Blood Cell (WBC). Peripheral blood smears were also performed to assess changes in the leucocyte differential count. Group A showed a progressive reduction in Hct and Hb levels over the experimental period, whereas Plt and WBC (P < 0.05) peaked at parturition. Among WBC, neutrophils increased until parturition when lymphocytes reached the lowest values. The statistical analysis also revealed significant interactions time × pregnancy on Hb (P < 0.001), WBC (P < 0.001), neutrophils (P < 0.001) and lymphocytes (P < 0.001). Analysing the last trimester of pregnancy and the first post partum period the present study provides suitable information about the influence of peripartum on mares' haematological parameters.