The trichostrongyloid parasites of sheep in South Australia and their regional distribution

Abstract

The species of trichostrongyloid nematodes present in 376 sheep from different agricultural regions of the state of South Australia were determined. Parasites encountered in the abomasum were Teladorsagia circumcincta, T. trifurcata, T. davtiani, Camelostrongylus mentulatus, Haemonchus contortus and Trichostrongylus axei. T. circumcincta was the species most commonly encountered, but C. mentulatus was widespread in arid areas. H. contortus was present in a small number of sheep only, mainly in southern areas. In the small intestine, Trichostrongylus vitrinus predominated in the wetter, southern districts, and T. rugatus in dry, northern areas. T. colubriformis was common, but was rarely dominant. T. probolurus was found in one sheep. Nematodirus filicollis was restricted to wetter, southern areas, while N. spathiger and N. abnormalis were widespread and predominated in dry areas. N. helvetianus was found once. Cooperia species were uncommon; species encountered were C. oncophora, C. surnabada and C. pectinata.

A survey of the prevalence ofNematodirus spathigerandN.filicollison farms in the North and South Islands of New Zealand

“…It has been inferred by the authors that climate is a key factor determining regional differences in the distribution of Nematodirus spp. in South Australia (Beveridge and Ford 1982). Vlassoff and McKenna (1994) concluded that the relatively uniform climate of New Zealand allows most parasite species to develop throughout the country and our conclusions on the distribution of N. spathiger and N. filicollis support this.…”

“…Whilst the climate in Iceland is more extreme and generally cooler than in most sheep farming areas of New Zealand it does indicate that both species can overlap. In contrast, differences in the regional distribution of these species were reported in South Australia, with N. filicollis found only in the southern wetter areas and N. spathiger predominated in low rainfall areas of the north and west (Beveridge and Ford 1982).…”

Helminth parasites of feral goats in South Australia

“…Regional differences in the occurrence of helminths of feral goats in South Australia generally follow the same pattern as that in sheep (Beveridge and Ford 1982 Camelostrongylus mentulatus was prevalent in feral goats from all pastoral zone sites, and occurs in sheep in the same areas (Beveridge and Ford 1982), but was not found at Williamstown and on Kangaroo Island. As the generic name implies, C. mentulatus is primarily a parasite of camels.…”

“…Oesophagostomum columbianum, Trichostrongylus probolurus and Trichuris ovis were the only helminth species found in Queensland which we did not find in goats in South Australia. However, the latter 2 species occur in sheep in this state (Beveridge and Green 1981;Beveridge and Ford 1982). With the exception of Nematodirella dromedarii, all the parasites found in goats in South Australia also occur in sheep in the state (Banks 1956(Banks , 1958Beveridge and Green 1981;Beveridge and Ford 1982).…”

Use of developmental temperature and gastrointestinal tract location to isolate pure Trichostrongylus vitrinus from mixed, naturally acquired trichostrongylid infections in sheep

“…Small intestinal Trichostrongylus species show variation in their geographic distribution (with overlap), influenced by rainfall and temperature, different pathogenicity and differences in host immune response . Trichostrongylus vitrinus is the most pathogenic of the Trichostrongylus spp .…”