The disclosure generally relates to the detection of symmetrical dimethylarginine (SDMA). More particularly, the disclosure relates to the detection of SDMA using a solid phase. The disclosure provides devices, reagents, kits and methods for detecting symmetrical dimethyl arginine (SDMA) in sample, such as a biological sample from an animal. The method includes detecting the presence or amount of SDMA in the sample by using an immunoassay format, such as a competitive immunoassay. The assay includes the use of antibodies to SDMA that are specific for SDMA and that have less affinity for other arginine derivatives.