title: Residual antibacterial activity of dog hairs after therapy with antimicrobial shampoos.
abstract: BACKGROUND
  Topical antimicrobial treatment for canine pyoderma is becoming increasingly important, but little is known about the mechanism of action and persistence of activity of antimicrobial shampoos.
  
  
  OBJECTIVE
  To determine the residual antimicrobial activity on canine hairs treated with antimicrobial shampoos.
  
  
  METHODS
  Forty-two dogs from a research institution.
  
  
  METHODS
  Dogs were treated with six different shampoos and the combination of one shampoo and conditioner containing benzoyl peroxide, chlorhexidine in different concentrations (0.8, 2, 3 and 4%), ethyl lactate and miconazole twice weekly for 2 weeks. A shampoo vehicle without antimicrobial ingredients was used as the control. Hairs were collected immediately after and 2, 4 and 7 days after the last shampoo therapy and placed onto an agar plate streaked with Staphylococcus pseudintermedius. After incubation, the growth inhibition zone around the hair shafts was measured.
  
  
  RESULTS
  The largest zone of inhibition of bacterial growth was seen after shampoos containing 2 and 3% chlorhexidine and the combination of chlorhexidine shampoo and conditioner. The zone of inhibition was smaller with the shampoos containing 0.8 and 4% chlorhexidine. There was no difference between the inhibition zones post-treatment with benzoyl peroxide, ethyl lactate and control.
  
  
  CONCLUSIONS
  The efficacy of a shampoo is dependent not only on the concentration of the active ingredients but also on the shampoo formulation. Hair shafts treated with shampoos containing 2 and 3% chlorhexidine and the combination of shampoo and conditioner inhibited bacterial growth significantly and seem suitable to treat canine bacterial pyoderma.
authors: Centre for Clinical Veterinary Medicine, Veterinary Faculty, LMU Munich, Veterinaerstraße 13, Munich, Germany.
authors: Isabell
authors: I
authors: Kloos
authors: Reinhard K
authors: RK
authors: Straubinger
authors: Christiane
authors: C
authors: Werckenthin
authors: Ralf S
authors: RS
authors: Mueller
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D018592:Cross-Over Studies; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D006197:Hair / Q000737:chemistry*; D006203:Hair Preparations / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D006203:Hair Preparations