Fluorescent bead-based multiplex assays improve serological disease diagnostics and have potential of identifying sensitive immune biomarkers for maintaining health and performance.

Fluorescent bead-based multiplex assays (multiplex assays) for serological detection of antibodies in patient samples have been used in veterinary diagnostics for a little over a decade. These quantitative assays offer several advantages compared to classical serological assays, like a lower limit of detection, less background, and a broader linear quantification range, all of which improve test accuracy. The simultaneous multiplex analysis of a patient's serological response to several specific antigens also improves the diagnostic result interpretation. This influences treatment and management decisions and often allows for a quantitative follow-up as treatment response evaluation. In this review article, we discuss examples of 3 diagnostic multiplex assays for antibody detection in veterinary patients: the Lyme Multiplex assay, the Canine Brucella Multiplex assay, and the Equine Herpesvirus Type-1 Risk Evaluation assay. In addition, multiplex assays for immune response markers, like soluble cytokines, chemokines, or other inflammatory proteins, have recently become available. Currently, these assays are mainly used as clinical research tools to broadly evaluate immune activation and/or inflammation during a variety of infectious and noninfectious diseases. Quantitative cytokine and inflammatory marker multiplex assays have the potential to identify sensitive immune biomarkers for maintaining health and performance in veterinary animals.