Frequency of dog erythrocyte antigen 1.1 expression in dogs from Portugal.

BACKGROUND Dog erythrocyte antigen (DEA) 1.1 is the antigen considered most responsible for severe hemolysis owing to incompatible blood transfusions in previously sensitized dogs. Few reports describe the frequency of DEA 1.1 expression in European dogs, and there are no reports in dogs from Portugal. OBJECTIVE The aims of this study were to identify the frequency of DEA 1.1 expression in Portuguese dogs, to examine the relationship between phenotypic traits and expression of this blood group, and to assess the risk of transfusing blood that is not typed or cross-matched. METHODS Expression of DEA 1.1 was determined in 274 dogs using a migration gel test. Weight, sex, breed, and hair length and color were recorded for each dog. Results were analyzed by descriptive statistical analysis, probabilistic analysis, and χ(2)-tests. RESULTS Of 274 dogs, 56.9% were DEA 1.1-positive and 43.1% were DEA 1.1-negative. All Boxers, German Shepherds, and Dobermans were DEA 1.1-negative, whereas all Saint Bernards, 88.9% of Golden Retrievers, 88.2% of Rottweilers, and 61.4% of mixed breed dogs were DEA 1.1-positive. A significant relationship between DEA 1.1 expression and phenotypic traits was not found. The probability of sensitization of recipient dogs following first-time transfusion with blood that was not typed or cross-matched was 24.5%; the probability of an acute hemolytic reaction following a second transfusion with blood from any other donor in the absence of pretransfusion compatibility testing was 6%. CONCLUSION The frequency of DEA 1.1 expression in dogs in Portugal is high, and there is a potential risk of sensitization following transfusion with blood that is not typed or cross-matched. Breed-related frequencies may help predict DEA 1.1-positivity, but the best practice is to type and cross-match blood before transfusion.