Sustainable helminth control of ruminants in developing countries.

Widespread anthelmintic resistance, at least amongst the important nematode parasites of small ruminants, threatens the sustainability of these livestock industries throughout both the developed and developing world. The exacerbation of this problem over the last decade or so, has provided the impetus for research into non-chemotherapeutic parasite control alternatives, such as host genetic resistance, grazing management, worm vaccines and biological control. Although some of these options provide practical benefits if currently adopted, or exciting prospects for the future, collectively they are unlikely to dispense with the need for the timely intervention of effective anthelmintic treatment. The issue of sustainability of helminth control practices therefore rests with the preservation of anthelmintic effectiveness through the implementation of principles of integrated pest management. Herein lies the difficulty-putting the principles into practice. Much of the research into sustainable nematode parasite control of ruminants has been done in the developed rather than the developing world, and the efforts to transfer this information to livestock owners has also been commensurately greater in the former. However the need for research and technology transfer is much more urgent in the developing world because of the lack of scientific and financial resources, the greater dependence on livestock industries and the much greater severity of the problem of anthelmintic resistance. This will require a major philosophical change in the affluent western world to the funding of national and international aid organisations who are largely responsible for these activities.