Evaluation of a polyvalent enzyme-linked immunosorbent assay incorporatinga recombinant p44 antigen for diagnosis of granulocytic ehrlichiosis in dogs and horses

Objective-To develop and evaluate a polyvalent ELISA incorporating a highly specific recombinant antigen (p44) for diagnosis of granulocytic ehrlichio sis in dogs and horses. Animals-32 dogs and 43 horses. Procedure-Results of the ELISA were compared with results of indirect fluor escent antibody (IFA) staining and western immunoblotting incorporating who le-cell antigen. Results-For the canine and equine samples, percentages of samples with posi tive IFA staining, western immunoblotting, and ELISA results were similar. For 29 (91%) canine samples and 30 (70%) equine samples, results of IFA sta ining, western immunoblotting, and the ELISA were in complete agreement. Re sults of the ELISA for 3 canine serum samples known to contain antibodies t o Ehrlichia canis and 12 equine serum samples known to contain antibodies t o E risticii were negative. Conclusions and Clinical Relevance-Results of the present study suggest tha t a polyvalent ELISA incorporating a recombinant p44 antigen is suitable fo r detecting antibodies to E equi in dogs and horses.