This purpose of this study was to compare the rapid slide agglutination test (SAT) with the agarose immunodiffusion test (AGID) on dog serum that had, or had not, received treatment with 2-mercaptoethanol. 1072 dogs' sera were included in this study. A positive reaction occurred in 202 samples with the AGID test (18,84%); nine in the ME-AGID test (0,84%); 19 in the SAT (1,77%) and nine in the ME-SAT (0,84%). The statistical e valuation concludes there is no divergence among the SAT, ME-SAT and ME-AGID tests, but did show significant difference with AGID.