Advances in control of ectoparasites in large animals.

In continuation of a publication on "Large-scale management systems and parasite populations: ectoparasites" in Vet. Parasitol. 11 (1982): 61-68, advances and present state of the control of ectoparasites in herds of cattle, sheep and camels are discussed. An intensified animal production necessitates permanent veterinary control of the status of ectoparasites. Strategically, control is basically directed towards achieving three aims: eradication, reduction of losses by means of dilution of ectoparasites regulations, and therapeutic measures. In the last few years, important progress has been made in effective ectoparasites control, mainly resulting from the discovery of new insecticides and acaricides, the improvement of the application techniques and the recent results in the biological control of arthropods; finally, an immunological approach will open new alternative ways of control. The control of mange and demodicosis in cattle; sarcoptic mange and sucking lice infestations in pigs; mange, biting lice infestations and nasal bots in sheep; ectoparasite infestations in camels and tick infestations are the main topics of the paper. The discovery of Ivermectin, a derivate of Streptomyces avermitilis which is now already fully integrated in to the spectrum of antiparasitic drugs, created a new generation of broad spectrum insecticides/acaricides. Current problems of the chemical control of arthropods, like the risk of residues in meat, milk and their products, the insecticide resistance and the possible environment pollution are critically outlined. But on the other hand, it can be predicted hypothetically that the amount of pest control measures in farm animals will increase in the near future to eliminate arthropods as causes of skin diseases and of damages to hides entailing negative effects on leather processing and as vectors of important infection agents. Finally, the proposal is submitted to elaborate international control programmes against ectoparasite species of global importance.