Could two common plant extracts hold the key to solving our equine deworming dilemmas? Recent study results from Germany suggest that a mixture of micronized coconut and onion have the potential to substantially decrease fecal egg counts in horses, and could possibly be used in place of the traditional anthelmintics (deworming drugs) to which many worms have become resistant.

In the two-part study, Heinz Mehlhorn, PhD, a professor at University of Duesseldorf, and his colleagues employed two groups of horses (one group of eight and one group of 12) naturally-infected mainly with nematodes (roundworms) and small numbers of trematodes (flukes) and cestodes (flatworms) to evaluate the palatability and anthelmintic capacity of two similar treatments:

  1. Treatment 1—700 grams of 40% micronized (pulverized into particles a few micrometers in diameter and, thus, easier to mix into normal feed) onions, 40% coconut flakes, and 20% glucose (essentially, sugar) and sugar beet; and 2.

  2. Treatment 2—1.2 kg of 25% coconut flakes, 25% micronized onions, and 50% horse feed muesli (a granolalike concentrate mixture produced by the German company Hoeveler).

Before the treatments began, Mehlhorn and colleagues performed fecal egg counts on all study horses. They repeated the fecal egg counts on Days 1, 3, and 5 after each 10-day treatment.

Part 1

The eight horses in Part 1 of the study had medium shedding rates, except for the youngest one, which had a high shedding rate. The researchers used this group of horses to test the palatability of the two treatments. They separated the horses into two subgr