AGE-related differences in the hematological profile of Andalusian broodmares of Carthusian strain

Normal hematological values need to be defined for each equine breed and age in order to increase diagnostic precision. No published data on hematology exist for Carthusian horses. This research compares the hematological characteristics of pregnant Carthusian broodmares of different ages. Forty-four pregnant Carthusian broodmares were divided into three age Groups: A (4-7 years; n = 18), B (8-12; n = 15) and C (13-17; n = 11). Jugular blood samples were taken every 14 days during pregnancy and data were pooled for each animal. The following hematological variables were determined: red blood cells (RBC), hemoglobin (HB), hematocrit (HCT), volumetric indices, white blood cells (WBC) and platelets (PLT). Furthermore, the numbers and percentages of lymphocytes (LYMP), band (BNL) and total neutrophils (NL), eosinophils (EOS), monocytes (MON), basophils (BAS) and the neutrophil/lymphocyte ratio (N/L) were counted on blood smears. Total serum protein concentrations (TSP) were also measured. The lower values of RBC, WBC, LYMP and PLT in the older broodmares (Group C) possibly reflected a decline in bone marrow activity. The lower RBC of these mares was compensated by an increased MCV. The higher NL values in Group C, both BNL and NL, could have represented subclinical infections, since these animals also presented the highest TSP. Likewise, the animals of Group C showed the highest EOS counts. This research demonstrated that ageing significantly influences the hematological values of Carthusian broodmares, with the most marked differences in mares older than 13 years and that these physiological variations must be taken into account in a clinical context.