Over the past few decades, it has been observed the emergence of antibiotic resistant microorganisms, among which stands out the Staphylococcus spp. methicillin-resistant (MRS). One of the major resistance mechanisms of the Staphylococcus is encoded by mecA gene, which is responsible for the production of additional penicillin-binding protein (PBP 2a), that has a low affinity for beta-lactam antibiotics. Analysis of the presence of this gene serves as an indicator and assists in selecting the best antimicrobial therapy. The purpose of this study was to detect phenotypic and genotypic strains form of MRS and to evaluate the antimicrobial resistance profile of these isolates. 80 Coagulase-positive Staphylococcus spp isolated were identified as S. pseudointermedius and evaluated by Oxacillin and Cefoxitin Disk Diffusion Tests and PCR amplified by a fragment of the mecA gene for the MRS strains characterization. Out of 2285 tests for antimicrobial drugs, 931 (40,74%) showed partial or total resistant. In phenotypic detection of MRS, 58.75% (47/80) of the isolates were oxacillin-resistant and 53.75% (43/80) were cefoxitin resistance. In genotypic detection, mecA gene was found in 23 isolates (28.75%), which only two presented both cefoxitin and oxacillin sensitivity in phenotypic test and only one presented resistance only to cefoxitin. In animals samples, mainly in Staphylococcus pseudintermedius isolates from dogs, cefoxitin is more sensitive than oxacillin to determinate resistance to beta-lactam antibiotics. Samples oxacillin and/or cefoxitin resistant showed higher both MAR and MCAR than isolated oxacillin / cefoxitin sensivity. The results for all antimicrobials tested have proven quite homogeneous to MRS samples detected phenotypically but not for the genotypic detection. However, despite the presence of the gene, it may not being phenotypically expressed.