| how long before resistance makes it impossible to control some field strains of haemonchus contortus in south africa with any of the modern anthelmintics? | this paper describes an exceptional spectrum of multiple anthelmintic resistance in two strains of haemonchus contortus in south africa, one from howick in kwazulu-natal, and the other from badplaas, in mpumalanga. apparently for the first time, a helminth strain is described with resistance to compounds from all five of the modern anthelmintic groups used for nematode control in sheep; also, two strains of h. contortus show resistance to the two substituted phenols, dinitrophenol and nitroxynil ... | 1997 | 9195715 |
| anthelmintic resistance in south africa: surveys indicate an extremely serious situation in sheep and goat farming. | surveys to determine the prevalence and degree of resistance of haemonchus spp. of sheep and goats to the available anthelmintics in south africa indicate that small ruminant production is entering a crisis situation. three surveys employing the faecal egg count reduction (fecr) test to determine resistance were conducted in some of the main sheep-producing areas in the summer rainfall region of south africa, where h. contortus is the principal worm species in sheep. after analyzing the data rec ... | 1999 | 10689700 |
| genetic parameters for resistance to haemonchus contortus in merino sheep in south africa. | resistance to natural infections of haemonchus contortus (wireworm) was studied in merino sheep. from february 1995 to july 1996 data were collected from the otk merino stud on the farm wildebeesfontein near hendrina in mpumalanga province. from march 1998 to january 2000 another merino flock at irene in gauteng province was included in the study. in both cases, 50 randomly-chosen animals from each group of lambs weaned were sampled weekly for faecal egg count (fec) until a mean of 2500 eggs per ... | 2002 | 12088074 |
| an overview of the eradication of brucella melitensis from kwazulu-natal. | brucella melitensis is a gram-negative bacterium whose primary hosts are goats and sheep. like the other brucelia spp., with the exception of brucella ovis, it is not particularly host specific as it is pathogenic for a variety of other mammal species including humans. in humans the disease caused by it is rated as one of the most important zoonoses. three outbreaks have been recorded in goats and sheep in south africa; the first outbreak occurred in sheep in 1965 in the mpumalanga and northern ... | 2002 | 12233997 |
| linognathus weisseri n. sp. (phthiraptera: linognathidae) of impalas, aepyceros melampus: description and biology. | the adult male and female and first instar nymph of the sucking louse linognathus weisseri n. sp. are described. this louse was collected from impalas, aepyceros melampus, at three localities in limpopo province, and at three in mpumalanga province, south africa. although it usually accounted for only a small proportion of the total louse burden, its overall prevalence exceeded 27%. its prevalence on adult male impalas (9%) was significantly lower (p = 0.004) than that on adult females (39%), bu ... | 2004 | 15185576 |