Prevalence and significance of gastrointestinal helminths and protozoa in South American Camelids in Switzerland

A cross sectional study was conducted to determine the prevalence and significance of endoparasitic infections in South American Camelids (SAC) in Switzerland. Qualitative and quantitative coproscopic examinations were performed in 38 farms during the grazing period. Management practices with possible interference with parasitic infections were analyzed. On the farm level prevalences of endoparasitic infections were: trichostrongyles 87%; Trichuris sp. 74%; Capillaria sp. 68%; Nematodirus battus 63%; Nematodirus sp. 53%; Dicrocoelium dendriticum 34%; Moniezia sp. 8%; Fasciola hepatica 5%; protostrongylids 5%; Eimeria macusaniensis 68%. The level of helminth egg excretion was generally low. The highest values were recorded for trichostrongyles with an average of all investigated farms of 53 eggs per gram of faeces. The mean trichostrongyle egg output was approximately three-fold in SAC on farms that also kept sheep and/or goats, although this difference was not significant (P = 0.11). Clinical trichostrongylidosis was not reported from any of the farms. The low infection level with gastrointestinal nematodes is attributed to the defaecation behaviour of the SAC depositing their faeces focally on small spots on pasture. As a consequence, pasture infectivity is largely restricted to the area adjacent to the dung piles. Dicrocoeliosis is regarded as the most relevant parasitic infection of llamas and alpacas in Switzerland causing severe clinical symptoms and death in untreated animals. Sixteen per cent of the owners regularily treated their herds against dicrocoeliosis using praziquantel at a dose of 50 mg/kg body weight orally.