Comparison of two methods for presurgical disinfection of the equine hoof

Objectives-To determine for equine hooves the normal resident aerobic bacte rial population and the efficacy of 2 methods of disinfection. Study Design-Measurement of total bacterial, gram-positive bacterial, and g ram-negative bacterial surface populations from the frog, sole, and hoof wa ll after each step of 2 different preoperative surgical disinfection techni ques. Animals-Six adult horses. Methods-Hoof wall, sole, and frog samples were collected for quantitative b acteriology before, during, and after 2 multistep antiseptic preparation te chniques: Method A-6-minute scrub with povidone-iodine soap, followed by 24 -hour submersion in povidone-iodine solution-soaked cotton; and Method B-in itial removal of superficial layer of hoof capsule before completing Method A disinfection procedures. Results-Removal of the superficial hoof layer, application of the povidone iodine scrub, and completion of the povidone-iodine soak all significantly (P < .0008) decreased total bacterial numbers. Method B had significantly l ower bacterial counts than method A at each consecutive step. Final total b acterial counts remained greater than 105 bacteria per gram of tissue regar dless of preparation method. Conclusions-The hoof surface hosts a broad spectrum of aerobic gram-positiv e and -negative bacteria, many of which are potential pathogens. Bacterial numbers can be significantly reduced by removal of the superficial hoof sur face, by application of a povidone-iodine scrub, and by use of a 24-hour po vidone-iodine soak. However, bacterial populations > 10(5) g per tissue per sist after these disinfection procedures. Clinical Relevance-Regardless of the preparation methods used in this study , bacterial populations capable of inducing wound infection remain on the h oof capsule. (C) Copyright 2001 by The American College of Veterinary Surge ons