The study aimed to determine the in vitro antimicrobial activity of Cefovecin (Convenia®/Pfizer), a new semi-synthetic broad spectrum cephalosporin, against clinical bacterial isolates obtained from dogs and cats in Sao Paulo state, Brazil. A total of 211 samples from several animals suspected of having skin (superficial and deep lesions), urinary tract and otic infections were examined. The clinical specimens of dogs and cats originated from Private Practices as well as Veterinary Hospitals during a 4 months period (August to December 2008) were submitted to laboratory microbiological examination. Swabs with cutaneous and ear samples and tubes containing urine samples were submitted to bacteriological culture and identification according to standard microbiological techniques. Subsequent susceptibility tests were performed utilizing 15 distinct antibacterial drugs, including Cefovecin. From the skin samples a total of 70 isolates were obtained. The principal isolated bacteria were Staphylococcus sp (n = 49). The other 21 isolates involved E. coli (n = 4), Proteus sp (n = 4), Pseudomonas sp (n = 1), Enterococcus sp (n = 3), Bacillus sp (n = 3), Klebsiella sp (n = 2) and Micrococcus sp (n = 4). The Cefovecin susceptibility against Staphylococcus sp, E. coli and Proteus sp isolates were 89,8% (44/49), 100% (4/4) and 100% (4/4), respectively. On the other hand the one Pseudomonas sp and three Enterococcus sp isolates were resistant to Cefovecin. Considering urinary samples analyzed, 20 isolates were identified and represented by E. coli (n = 5), Proteus sp (n = 2), Staphylococcus sp (n = 7), Enterococcus sp (n = 3), Klebsiella sp (n = 1), Pseudomonas sp (n = 1) and Streptococcus sp (n = 1). Both E. coli (5/5) and Proteus sp (2/2) isolates had in vitro susceptibility of 100% whereas staphylococcal samples showed a value of 85,7% (6/7). From the ear samples 118 otic isolates was achieved. Staphylococcus sp (n = 60) represented the majority whereas gram-negative were represented by E. coli (n = 9), Proteus sp (n = 12) and Pseudomonas sp (n = 21). Against Staphylococcus sp, E. coli and Proteus sp, the susceptibility of Cefovecin were respectively 96.7% (58/60), 88.9% (8/9) and 91.7% (11/12). The remaining isolates were Bacillus sp (n = 5), Corynebacterium (n = 3), Enterococcus sp (n = 3) and Klebsiella (n = 5). All Pseudomonas sp and Enterococcus sp strains were resistant. Based on the in vitro susceptibility results obtained in this study, Cefovecin were a suitable antibiotic therapeutic option in the treatment of dogs and cats with pyoderma, urinary tract infections as well as bacterial otitis. The exception is when Pseudomonas sp and/or Enterococcus sp play a role as primary bacterial pathogens involved.