Herbal dewormer fails to control gastrointestinal nematodes in goats

Gastrointestinal nematode (GIN) parasitism is the most important disease of small ruminants. Control is usually based on the use of chemical anthelmintics (dewormers); but these are prohibited from use in organic livestock, and the effectiveness of chemical anthelmintics in conventional operations is limited by high levels of anthelmintic resistance. Consequently, herbal dewormers are increasing in popularity as an alternative to chemical dewormers for GIN control. However, the effectiveness of herbal dewormers remains unproven. The objective of this study was to examine the effectiveness of a commercially available herbal dewormer to control GIN in goats. Lactating (n=16) and young (n=8) dairy goats grazed poor quality mixed grass pastures between March and July 2006 at the Heifer International Ranch in Perryville, AR. Goats were supplemented with grass hay and concentrate. Goats were untreated or administered herbal dewormer (n=12/treatment) according to manufacturer recommendations. FAMACHA scores (1=red or healthy; 5=severely anemic) were determined and fecal samples collected for fecal egg count (FEC) determination every 14 days between Days 0 (day of first herbal treatment) and 112. FAMACHA scores in the herbal treated group were greater than in the untreated control group (P<0.005), indicating a higher level of anemia. FEC were greater for herbal treated goats on Pasture A compared with B by Day 42, but similar among groups thereafter. FEC (P<0.03) and FAMACHA scores (P<0.001) were greater in lactating than in non-lactating goats. Herbal dewormer treatment yielded no measurable health benefits indicating that the herbal dewormer failed to control GIN in these goats.