Infective larvae of selected batched of the following nematode species from sheep and cattle were examined for survival and infectivity (by injection into either the abomasum, the duodenum, or the jugular vein) after having been stored in liquid nitrogen for 103-136 months: Haemonchus contortus, Haemonchus placei, Ostertagia circumcincta, Ostertagia ostertagi, Marshallagia marshalli, Cooperia s...

During a pilot survey of the parasites of some artiodactylids in the Kalahari Gemsbok National Park a new species of Trichostrongylus Looss, 1905 was recovered from the small intestine of a steenbok, Raphicerus campestris (Thunberg, 1811), a gemsbok, Oryx gazella (Linnaeus, 1758), and a red hartebeest, Alcelaphus buselaphus (Pallas, 1766). The male spicules were 0,120-0,148 mm long and an ear-s...

A group of 12 Merino lambs, 3,5 months of age, which were still suckling, were each dosed with 40 000 infective larvae of Trichostrongylus axei on Day 0. From Day +62-Day 64 each of these lambs and those of a 2nd group of 11 controls were dosed with 30 000 infective larvae of Haemonchus contortus, and all the lambs of both groups were killed on Day +90. Attempts to use T. axei to protect them a...

Thirteen bushbuck, Tragelaphus scriptus, and 13 grey duikers, Sylvicapra grimmia, were culled in the Weza State Forest, Natal, from May 1983-May 1984. The maximum number of worms recovered from a single bushbuck was 393. Of the total number of worms recovered from all the bushbuck, Paracooperia devossi were the most numerous, followed by Ostertagia harrisi, a Cooperia sp. and Haemonchus vegliai...

As the prevalence and severity of anthelmintic resistance continue to rise, nematode infections in sheep correspondingly reduce the profitability of the sheep industry. In Costa Rica, sheep production systems are increasing in both number and importance. A field trial study was carried out to detect the level of anthelmintic resistance to albendazole and ivermectin in gastrointestinal nematodes...

From July 1979-December 1980, 48 springbok were culled for a parasite survey at Benfontein. Lice were the dominant parasites and reached a peak in September. Damalinia antidorcus, Linognathus antidorcitis, Linognathus armatus and Linognathus euchore were the most prevalent species, nymphs in most cases outnumbering adults. During the winter months, 2nd and 3rd instar Rhinoestrus antidorcitis an...

This study aimed to identify the parasites that inhabit the digestive system of Sus scrofa scrofa from a commercial breeding facility in southern Brazil, and reports the first occurrence of Trichostrongylus colubriformis in wild boars. The gastrointestinal tracts of 40 wild boars from a commercial breeding facility were collected and individualized during slaughter in a cold-storage slaughterho...

Seasonal forcing represents a pervasive source of environmental variability in natural systems. Whilst it is reasonably well understood in interacting populations and host-microparasite systems, it has not been studied in detail for host-macroparasite systems. In this paper we analyse the effect of seasonal forcing in a general host-macroparasite system with explicit inclusion of the parasite l...