Evaluation of the number of colony forming units on the skin of dogs after clipping the hair with two sizes of clipper blades

Abstract

OBJECTIVE: To evaluate erythema and number of CFUs on the skin of dogs with hair clipped by use of 2 sizes of clipper blades. ANIMALS: 67 client-owned dogs receiving an epidural. PROCEDURES: Hair was clipped with a No. 10 blade (approx hair length, 1.5 mm) on one half and a No. 40 blade (approx hair length, 0.25 mm) on the other half of each epidural site. Skin was surgically scrubbed with 2% chlorhexidine gluconate and 70% isopropyl alcohol. Samples were obtained immediately after clipping, after skin was scrubbed, and again 24 hours after clipping. Number of CFUs for both sides of the clipped areas, types of microorganisms, and growth on MacConkey agar were evaluated every 24 hours for 72 hours. Colonies were evaluated for bacterial morphology and Gram stain characteristics. Sites were evaluated 24 hours after clipping for evidence of erythema. RESULTS: 24 hours after hair was clipped, there was a significantly higher incidence of erythema and higher number of Micrococcaceae bacteria for the side clipped with the No. 40 blade than the side clipped with the No. 10 blade. Number of CFUs did not differ significantly between size of clipper blades. CONCLUSIONS AND CLINICAL RELEVANCE: Clipping hair with a No. 40 blade resulted in a significant increase in the incidence of erythema and higher number of Micrococcaceae bacteria, compared with results for clipping with a No. 10 blade. These results supported use of a No. 10 clipper blade to prevent erythema and reduce variation in the skin microbiome.