Your questions about strategically deworming horses, answered by an expert.

How often should you deworm a horse? Can you overdo it? Do natural dewormers work? Can my dogs give my horses their worms? Members of who participated in The Horse's Strategic Deworming Webinar asked these questions and about 70 more–and they received answers by presenter Heidi A. Brady, PhD, an associate professor at Texas Tech University, during the Aug. 7, 2008 webinar. A complete transcript of these questions and answers follows.

For the complete video presentation along with the questions and answers, visit You'll need to be a member of to watch the webinar; if you haven't already done so, create a login or sign in to watch!

Q: There seem to be many opinions as to the frequency of worming, how do we decide what is appropriate? Quarterly, bi-monthly, monthly?

A: You have asked a very important question and one that is not simple to answer. A complex number of factors should be looked at. Without baseline fecal egg counts on your horses, you really do not have a good basis for making a decision. Further, without FECRT (fecal egg count reduction tests; more on these later), the possible resistance of the parasites in your group of animals is unknown. We are advocating a comprehensive approach where a screening can be done for your farm and based on what is seen, specific recommendatio