Intense laboratory tests on experimentally infected mice and rats had shown that a mixture of micronized onions and coconut pulp decreases substantially (until disappearance) the worm load (trematodes, cestodes and nematodes) after oral uptake. As a consequence, feeding experiments of naturally infected sheep had been done in Egypt, in Saudi Arabia, and in Germany, which showed that treated animals grow up much better than untreated ones. The mean gain of body weight per animal was up to 6 kg within 4 weeks compared to untreated ones. These experiments were repeated again in the present study with naturally infected sheep and horses in Germany. Two types of professionally produced forage had been used: (1) mixture of 40% micronized onions, 40% coconut flakes, and 20% glucose besides sugar beet treacle; (2) mixture of 25% coconut flakes, 25% micronized onions, and 50% of the so-called muesli forage of Fa. Höveler, Dormagen, Germany consisting of some oils plus 20 different plant extracts and several vitamins. All experiments showed that feeding for 10 days led either to the full disappearance of the previously existing worm load or at least to an enormous reduction. When comparing the body weights of infected sheep before the start of the feeding and 4 weeks later, it was found that there was an increase of 5-8 kg (mean 7.5 kg) body weight in each treated animal, while nontreated ones had only weight increases between 0 and 5 kg (mean 2.37 kg). In the case of the horse treatment, the worm load decreased so enormously that mostly only single eggs or larvae were found in those horses that had accepted the onion-coconut food addition.