Evaluation of Skin Bacterial Flora Before and After Aseptic Preparation of Clipped and Nonclipped Arthrocentesis Sites in Horses

Authors

  • BRENT A. HAGUE DVM,

    Corresponding author
    1. Department of Large Animal Medicine and Surgery, and the Department of Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX
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  • CLIFFORD M. HONNAS DVM, Dipiomate ACVS,

    1. Department of Large Animal Medicine and Surgery, and the Department of Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX
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  • R. BRUCE SIMPSON DVM, MS, Dipiomate ACVM,

    1. Department of Large Animal Medicine and Surgery, and the Department of Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX
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  • JOHN G. PELOSO DVM, MS, Dipiomate ACVS

    1. Department of Large Animal Medicine and Surgery, and the Department of Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX
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Department of Large Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station, TX 77843

Abstract

Objective—This study evaluates skin bacterial flora before and after aseptic preparation of clipped and nonclipped arthrocentesis sites in horses.

Study Design—The hair over one midcarpal joint and one distal interphalangeal joint on each horse was clipped. The contralateral joint served as the nonclipped comparison.

Animals or Sample Population—Twelve adult horses.

Methods—A prescrub sample for microbial culture was taken from the dorsal surface of all four joints for each horse. Each site was aseptically prepared with povidone iodine and 70% alcohol, followed by postscrub sampling for microbial culture. Colony forming units (CFUs) were determined for each sample, 24 hours after inoculation of blood agar plates.

Results—There was no significant difference (P >.05) in number of postscrub CFUs between clipped and nonclipped skin over the midcarpal or distal interphalangeal joints. Percent bacterial reduction (mean ± SD%) after aseptic preparation differed significantly (P=.02) between clipped (99.8 ±.003%) and nonclipped (96.2 ±.05%) skin at the midcarpal joint, but not at the distal interphalangeal joint (clipped, 98.5 ±.03% and nonclipped, 97.8 ± 0.21%). There was a significant difference (P=.009) in number of prescrub CFUs obtained from clipped and nonclipped skin for the midcarpal joint. There was no significant difference in number of prescrub CFUs between clipped and nonclipped skin at the distal interphalangeal joint. Bacteria isolated from both clipped and nonclipped skin sampled postscrub included Bacillus sp, nonhemolytic Staphylococcus sp, and Micrococcus sp.

Conclusions—The presence of hair over the midcarpal and distal interphalangeal joints does not appear to inhibit the ability of antiseptics to effectively reduce bacterial flora to an acceptable level for arthrocentesis.

Clinical Relevance—Aseptic preparation of the skin over the midcarpal and distal interphalangeal joints can be accomplished without hair removal in horses.

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