Characterization of the Microbial Flora Isolated from Horses with Hoof Thrush and Their Sensitivity for Selected Antibiotics

The horse industry is a large industry with a high scope for growth and employment. It encompasses production and nurturing of horses, as well as other activities involving horses. The domestic horse industry in South Korea has shown remarkable growth since the Horse Industry Promotion Act was enacted in 2012. However, research on horse health-care, especially hoof diseases, is insufficient. The most frequent hoof diseases in Korea are thrush, cracks, and white line disease. In this study, we aimed to identify the causative agents of thrush, the most frequent hoof disease among horses in Korea, and perform antibiotic sensitivity tests on the isolates. In 55 samples collected from 47 horses diagnosed with thrush during grooming among 2,973 horses raised in Korea, and the causative agents, Bacillus spp., Streptococcus spp., Staphylococcus spp., Pseudomonas spp., Enterococcus spp., Aerococcus spp., Corynebacterium spp., Clostridium spp., and Aspergillus flavus. However, Fusobacterium necrophorum was not isolated from horses with thrush in Korea. Moreover, antibiotic susceptibility tests for these isolates showed that they were sensitive to most of the 22 antibiotics tested, including amikacin. This is attributable to the fact that the treatment and prevention of thrush is primarily focused on stall and hoof management procedures, such as grooming, and that antibiotics have not been used for treatment. These results are expected to greatly contribute to the treatment of equine hoof diseases, especially thrush, in Korea. Research with more samples can improve our understanding of the relationship between thrush and occurrence of other hoof diseases.