Saturday, August 20, 2016

Results of DrenchRite® Test

A pooled fecal sample was collected from the goats on August 3. It was sent to Dr. Ray Kaplan's lab at the University of Georgia for a DrenchRite® test. A DrenchRite® test determines whether barber pole worms from a manure sample are resistant or susceptible to the four groups of dewormers commonly used in goats. The test also determines the fecal egg count of the sample and identifies the type of parasites in the sample.

The fecal egg count of the pooled sample was 2700 epg. In comparison, the average fecal egg count of the individual samples collected on August 3 was 1940 ± 1865 epg. The sample contained 95 percent barber pole worm (Haemonchus contortus) and 5 percent Trichostrongylus/Teladorsagia, with some Strongyloides. In comparison, samples collected from the goats upon arrival (on June 23-24) contained 70 percent Haemonchus.

The DrenchRite® test showed that a significant portion of the worm population (in the manure sample) was resistant to all four dewormer groups.  However, the actual efficacy of anthelmintic treatment could be anywhere from 0 to 95 percent. If resistance is low, the drug may still be highly effective. 

Combination treatments (2 or more drugs) may also result in an effective treatment. In other countries, products containing multiple drug combinations are commercially available. In the US, it is necessary to use different drugs sequentially, as is done when the goats arrive to the test site.  Combining dewormer use with the administration of copper oxide wire particles (COWPs) may also result in an effective treatment.

Dewormer group Trade names Resistance status
Benzimidazole (BZ) Panacur®, SafeGuard®, Valbazen® Resistant
Levamisole (LEV) Tramisol®, Levasol®, Prohibit®, LevaMed®
Ivermectin (IVM) Ivomec®, Eprinex®, Dectomax® Resistant
Moxidectin (MOX) Cydectin® Resistant

Read article about DrenchRite® Assay Test