Document Type

Honors Project

First Advisor

Dr. Michael Hensley

Degree Award Date

Fall 2007


Fenbendizole, endoparasites, Strongyle Fecal Egg Counts, Equine Herd, Augusta County Virginia


Large or Food Animal and Equine Medicine | Veterinary Infectious Diseases | Veterinary Medicine | Veterinary Microbiology and Immunobiology | Veterinary Pathology and Pathobiology


The family of endoparasites known as the "strongyles" poses a significant health risk to .equine hosts, and infection with these helminths is a constant problem. An additional cause for concern in recent years has been the emergence of strongyle populations that are resistant to commonly used antihelmintic compounds such as fenbendazole. The purpose of the study was to determine whether a significant reduction in strongyle fecal egg counts would be observed over time in horses treated with fenbendazole when compared to the fecal egg counts of untreated horses within the same herd. The null hypothesis stated that there is no difference in the mean strongyle fecal egg counts between horses treated with fenbendazole and horses not treated with fenbendazole. Fecal samples were collected from nine horses over the course of five weeks, and fecal egg counts were conducted to determine the fluctuation in the number of strongyle eggs passed in the weeks following antihelmintic treatment. Chi-squared analyses were used to gauge the degree of reduction of strongyle FECs in the treatment group. The null hypothesis was rejected, and it was concluded that fenbendazole was effective in reducing the strongyle fecal egg count of treated horses for a period of two weeks.