Dr. Murai Éva szerk.: Parasitologia Hungarica 25. (Budapest, 1992)

From New Zealand llamas, Arthur (1991) demonstrated the nematode genera Nematodirus, Ostertagia, Trichostrongylus and Cooperia. He established that the anthelmintics used in domestic ruminants can be successfully used also in llamas. Gevrey (1991) reported on an experiment conducted in Lyon, in which 6 ewes and 7 llamas were kept on the same pasture for 21 days (from 3 to 24 March). He found that parasitic infections were intertransmissible between the two species. By faecal examination, first Trichostrongylus and Trichuris spp. were demonstrated from both llamas and sheep. Later on, the lancet fluke (Dicrocoelium lanceolatum) was also found in both species. (Trichostrongylus colubriformis and Metastrongylus species were also observed at postmortem examination). The lambs that had been raised helminthfree were infected by larvae present in the llamas' faeces. Their abomasum was found to contain Trichostrongylus colubriformis while in their small intestine Metastrongylus spp. were present. Therapy and prevention of nematode infection Ruminants affected with nematode infections are often treated with benzimidazole derivatives. Several of the benzimidazole derivatives have the advantageous property of destroying both the eggs and the hypobiotic nematode larvae (Kassai 1989). Cheney and Allen (1989) tested the efficacy of preparations that had already been tried out in other ruminants, e.g. mebendazole, fenbendazole, thiabendazole, levamisole or ivermectin. They found that levamisole was slightly toxic when used simultaneously as a pour-on against ectoparasites. Of the preparations tested, ivermectin and fenbendazole were the most effective against the nematode parasites of llamas. Vermitan, a preparation containing albendazole as active ingredient, has been used successfully against the endoparasites of sheep and cattle. When administered at a dose of 7.5 mg/kg body weight, it had 99-100% efficacy against the adult stages of Haemonchus, Ostertagia, Cooperia, Trichostrongylus and Oesophagostomum. At a lower dose, it showed 95% efficacy against Bunostomum infection. Against Trichuris species, however, the efficacy of Vermitan administered at a dose of 10 mg/kg body weight was only 83%. Albendazole is effective against fasciolosis, too (Merényi 1990). The basic aim of anthelmintic treatment is to destroy the adult worms. The following two basic processes are essential for the survival of adult worms: - Availability of chemical energy for the different vital functions (energy-generating metabolic processes). - Possibility to feed within the host organism (neuromuscular coordination). Depending on their active ingredient, anthelmintics have different points of attack. Albendazole belongs to the benzimidazole compounds which exert their effect through the inhibition of energy-producing metabolic processes. They locally block the fumarate reductase enzyme system, thereby inhibiting mitochondrial function; as a result, energy release will be inhibited. Albendazole kills helminths through its metabolites (albendazole sulfoxide, albendazole sulfone) "detoxified" by the host organism. It is absorbed through the wall