[Gastrointestinal parasitoses in sheep. Diffusion and economic impact]

anthelminthique anthelmintics antielmintici apparato digerente appareil digestif application rates control de plagas controllo dei parassiti controllo dell'inquinamento digestive system dose d'application dosi di applicazione drug therapy elmintosi encuestas sobre plagas epidemiologia epidemiologie epidemiology helminthose helminthoses helmintiasis infestation infestazione inquinamento losses lutte antipollution lutte antiravageur mortalidad mortalite mortality organisme nuisible aux animaux ovin ovini ovinos parassiti degli animali perdite perte pest control pest surveys pests of animals plagas de animales pollution pollution control productividad productivity residues residui residuos sheep sistema digestivo strongylidae terapia farmacologica trichostrongylidae