Prevalence of Ca Blood Type and Alloantibodies in a Population of Horses from Italy

SIMPLE SUMMARY: Indications for whole blood transfusion in equine critical care include severe anemia from surgical blood loss or acute hemorrhage, hemolysis and neonatal isoerythrolysis. In horses, as in other animals, transfusions are associated with a number of inherent risks such as transfusion reactions. Pretransfusion screening and blood typing are indicated to minimize the risk of incompatible red cell transfusions. Equine blood types include seven systems, namely A, C, D, K, P, Q, and U. The major RBC antigens that warrant identification before packed RBC or whole blood transfusions in horses are Ca and Aa. The frequencies of blood groups can vary from one population to another and from one breed to another. In some situations where testing compatibility is not possible, such as in rural practice, the knowledge of the breed blood type frequencies may help selecting the best donor candidate. The aims of this study were to: estimate the prevalence of Ca blood type in horses from northern Italy; estimate the association between Ca blood type sex and breed of horse; estimate the prevalence of anti-Ca alloantibodies in Ca− horses. The prevalence of the Ca+ blood type was 79.1%. No significant association was found between blood type Ca and sex. The total number of Ca− samples with detectable anti-Ca alloantibodies was 7/23 (30.4%). ABSTRACT: A knowledge of the blood groups and alloantibodies present is essential for the safe transfusion of blood products in horses. Pre-transfusion screening and blood typing minimizes the risk of incompatible RBC transfusions and prevents immunization of the recipient against incompatible RBC antigens. The frequencies of blood groups can vary among different breeds. Knowledge of a breed’s blood group prevalence can be very useful for identifying the best blood donors during transfusion in clinical practice. The aims of this study were to estimate the prevalence of the Ca blood type in horses from Italy using a monoclonal immunocromatographic method and to estimate the prevalence of anti-Ca alloantibodies in Ca− horses using agglutination on gel technique. Ca blood type was determined on 110 whole blood samples. The prevalence of the Ca+ blood type was 79.1%. This study also provides data about the prevalence of Ca+ blood group in Italian Saddle Horses (77,3%) and Dutch Warmblood (58,3%). No significant association was found between Ca blood type and sex with 79.5% and 78.8% of females and males testing Ca+, respectively. The total number of Ca− samples with detectable anti-Ca alloantibodies was 7/23 (30.4%).