In recent years the increase in reports of antibiotic resistance has made the introduction of new therapeutic strategies necessary. In the dog, the use of topical antiseptics for superficial pyoderma has proven of equivalent efficacy compared to systemic antibiotics. In particular, in canine surface pyoderma topical antiseptics have often shown equal efficacy compared to antibiotic treatments. Aim of this study was to test the in vitro antibacterial efficacy of a shampoo/conditioner containing blackcurrant seed oil, piroctone olamine, 18-beta-glycyrrhetic acid and ceramides. Fifty (50) bacterial strains were selected from dogs with superficial pyoderma, consisting of: 10 Staphylococcus pseudintermedius, 10 Staphylococcus aureus, 10 methicillin-resistant Staphylococcus pseudintermedius, 10 Escherichia
coli and 10 Pseudomonas aeruginosa strains. A concentration of 106 CFU/mL of selected bacteria was used for serial dilutions in a 96-well sterile plate; the wells were filled with 100ml of the tested shampoo (Ribes Pet Shampoo® Ultra, NBF Lines, Milan) and dilutions were incremented from 1:2 to 1:256. After incubation for 30 minutes at 37°C an aliquot of 10ml was taken from each well, seeded on Tryptone Soya agar with 5% sheep blood and incubated for 24 hours to evaluate the MIC. The product showed bactericidal activity against all strains up to and including the 1:16 dilution. At 1:34 dilution the first bacterial growth was shown for 4 MRSP, 4 P. aeruginosa, 2 S. pseudintermedius and 2 E. Coli strains; at 1:64 dilution for 6 S. pseudintermedius, 6 S. aureus, 4 MRSP, P. aeruginosa and E. Coli strains; at 1:128 dilution for 4 E. coli, 2 MRSP, S. pseudintermedius, S. aureus and P. aeruginosa strains. Finally, at 1:256 dilution growth was shown for only 2 strains of S. aureus.