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March 2014
Do Herbal Dewormers Work?


Dr. Dahlia O'Brien
Virginia State University

Internal parasite infections are a major cause for reduced productivity in the sheep and goat industry. Before the use of chemical dewormers became widespread, many livestock farmers used natural plant remedies in their herd/flock to control these infections.


With emerging dewormer resistance and an overall increase in the desire to promote sustainability, the use of non-chemical dewormers is desired and sometimes preferred. To this end, the use of commercially-available herbal dewormers might be a promising and viable alternative to chemical control. But, how effective are they in controlling internal parasites?

Over the last few years, a number of studies have been done to test the effectiveness of commercially available herbal dewormers. Most recently, two studies were conducted at Delaware State University to test how effective Hoegger’s Herbal Wormer was in reducing fecal egg counts in meat goat kids and lactating does.

This dewormer is distributed by Hoegger’s Goat Supply (Fayetteville, GA) and contains a mixture of dried plant materials including wormwood, gentian, fennel, psyllium and quassia. Individually, these ingredients have all been reported

to have possible deworming properties capable of reducing internal parasites in livestock. However, most of this information is anecdotal and not supported by scientific data. 


So far, scientific studies evaluating commercial, non-chemical dewormers have found that they fail to reduce fecal egg counts in sheep and goats. The results from these two studies also supports that at the recommended dose and under the conditions of the studies, Hoegger’s Herbal Wormer was not an effective dewormer.

There are still many producers that claim when combined with other methods of parasite control on their farms, such as pasture rotation, including a herbal wormer has been effective in reducing the number of animals requiring chemical treatment. However, when it comes to herbal dewormers, there is insufficient scientific data supporting their claims of effective parasite control. 

These products contain varying amounts of dried plant materials and doses that might not be enough to offer effective control. Therefore, herbal products alone should not be relied on for controlling/treating internal parasites. If their use is desired, they should always be combined with other integrated parasite management techniques.

In addition, it is important to know the status of drug resistance on your farm so that these techniques can also be used in conjunction with an effective chemical dewormer to prevent/reduce animal losses associated with parasitism.


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