Occurrence, hematologic and serum biochemical characteristics of neonatal isoerythrolysis in Arabian horses of Iran

Neonatal isoerythrolysis is a major cause of anemia in newborn foals. However, there are no documented data regarding the occurrence of neonatal isoerythrolysis in Arabian horses of Iran, which are mostly raised in Khouzestan province. Hence, this study was carried out to investigate the occurrence of neonatal isoerythrolysis in Arabian horses of Khouzestan and assess the hematologic and serum biochemical profile of affected foals. A total of 20 neonatal foals, under one week of age, and their dams were involved in this study. Clinical examinations revealed no abnormality except in one foal with icteric mucous membranes, lethargy, tachycardia, tachypnea, hypothermia and hemoglobinuria which led to death. The diagnosis of neonatal isoerythrolysis was made based on erythrocyte agglutination in crossmatch test between the mare serum and foal erythrocytes with the titer of 1:128, while other studied cases were assumed negative according to the test results. In the laboratory assessment, the foal with hemolytic anemia showed a major decline in hematocrit, hemoglobin concentration and erythrocyte count along with considerable leukocytosis and neutrophilia. Serum total and direct bilirubin concentrations in the NI case was about ten times higher than in the rest of the foals. This study revealed that neonatal isoerythrolysis can occur in Arabian foals of Khouzestan and is associated with severe anemia and icterus which may lead to death. These findings can be beneficial in the establishment of preventive measures in Arabian horse breeding industry in the region, as well as improving therapeutic methods.