Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| high genetic correlation between resistance to haemonchus contortus and to trichostrongylus colubriformis in inra 401 sheep. | to compare the protection acquired by infection with haemonchus contortus or trichostrongylus colubriformis, successive cross infections with the two species were conducted in two genetically similar groups of 150 ewe lambs from 30 sires of inra 401 breed. at 6 and 7.5 months of age, each group received two doses of 10000 l3 separated by a treatment of one of the species, followed by a similar infection with the second species at 9 and 11.5 months. faecal egg counts (fecs) were done 28 and 35 da ... | 2004 | 15036576 |
| field studies on the biological control of nematode parasites of sheep in the tropics, using the microfungus duddingtonia flagrans. | long-term field studies were conducted on two government managed small ruminant research farms, located in different geo-climatic regions and approximately 300 km separate from each other, on peninsula malaysia. the infoternak trial (48 weeks) and the chalok trial (43 weeks) each compared nematode parasite control in separately managed groups of young sheep, either short-term rotationally grazed around a suite of 10 paddocks in addition to receiving a daily supplement of duddingtonia flagrans sp ... | 2004 | 15041093 |
| aspartyl proteases from the intestinal brush border of haemonchus contortus as protective antigens for sheep. | a novel pepsin-like aspartyl protease was identified as a component of haemonchus galactose-containing glycoprotein (h-gal-gp), which is an integral membrane glycoprotein complex located on the intestinal cells of haemonchus contortus, and a highly protective antigen for sheep. this molecule, designated hcpep2, showed 50% sequence identity with a previously described aspartyl protease from h-gal-gp known as hcpep1. fractions of h-gal-gp, either containing both hcpep1 and 2 or other lower molecul ... | 2003 | 15053773 |
| capability of the nematode-trapping fungus duddingtonia flagrans to reduce infective larvae of gastrointestinal nematodes in goat feces in the southeastern united states: dose titration and dose time interval studies. | infection with gastrointestinal nematodes, particularly haemonchus contortus, is a major constraint to goat production in the southeastern united states. non-anthelmintic control alternatives are needed due to increasing resistance of these nematodes to available anthelmintics. two studies were completed in central georgia in august 1999, and april-may 2000, using spanish does naturally infected with haemonchus contortus, trichostongylus colubriformis, and cooperia spp. to evaluate effectiveness ... | 2004 | 15063939 |
| in vivo electroporation improves immune responses to dna vaccination in sheep. | in vivo electroporation was utilised to enhance plasmid dna expression in sheep muscle to improve the immune response to dna vaccination. dna encoding enhanced green fluorescence protein expressed at higher levels in sheep muscle following in vivo electroporation which caused minimal muscle damage. groups of seven sheep were then given three intramuscular injections of plasmids encoding two haemonchus contortus ag, with and without electroporation at 0, 3 and 7 weeks. humoral responses were enha ... | 2004 | 15068866 |
| moxidectin-resistant haemonchus contortus in sheep in northern new south wales. | 2003 | 15080459 | |
| binding of hematin by a new class of glutathione transferase from the blood-feeding parasitic nematode haemonchus contortus. | the phase ii detoxification system glutathione transferase (gst) is associated with the establishment of parasitic nematode infections within the gastrointestinal environment of the mammalian host. we report the functional analysis of a gst from an important worldwide parasitic nematode of small ruminants, haemonchus contortus. this gst shows limited activity with a range of classical gst substrates but effectively binds hematin. the high-affinity binding site for hematin was not present in the ... | 2004 | 15102788 |
| speckle interferometry applied to pharmacodynamic studies: evaluation of parasite motility. | the work reported here describes the application of the optical technique known as dynamic speckle interferometry to evaluate the motility of nematode parasites exposed to different anthelmintic drugs. this technique, a well proven tool for assessing the time evolution of different phenomena, is here successfully used to quantify parasite motility in pharmacodynamic assays. the characterization of the pharmacological properties of anthelmintic drugs is critical to optimize their use in parasite ... | 2004 | 15133648 |
| concurrent parasitic infections of sheep: depression of trichostrongylus colubriformis populations by a subsequent infection with oestrus ovis. | concurrent infections of sheep with oestrus ovis and trichostrongyles of the digestive tract are common in the field. previous results have shown that a previous infection with o. ovis adversely affects worm populations of either trichostrongylus colubriformis or haemonchus contortus. however, no information was available to determine the influence of the succession of infections on the expression of interactions between these parasites located in remote anatomical sites. in order to investigate ... | 2004 | 15135870 |
| morphological identification of nematode larvae of small ruminants and cattle simplified. | a simplified system has been developed to facilitate identification of nematode larvae of the common nematodes of cattle, sheep and goats. firstly, in addition to the characteristics conventionally used for identification (such as the shape of the cranial extremity and numbers of intestinal cells), the lengths of the infective sheath tails of infective larvae of each genus/species are related to that of trichostrongylus spp. instead of using measurements for differentiation. for instance, if the ... | 2004 | 15154594 |
| variability in the resistance of the nigerian west african dwarf goat to abbreviated escalating trickle and challenge infections with haemonchus contortus. | the west african dwarf (wad) goat is known to be relatively resistant to infection with haemonchus contortus. an experiment was carried out to assess variability in resistance under escalating trickle and single pulse challenge infection protocols. thirty two 7-8 month old goats were subjected to trickle infection beginning with a thrice weekly dose of 100 l3 and increasing to 500 l3 by week 5, the last dose being administered on d30. infection was abbreviated with fenbendazole on d32 and the an ... | 2004 | 15158556 |
| haemonchus contortus: in vitro drug screening assays with the adult life stage. | motility and feeding assays were assessed as in vitro systems for screening of novel compounds for anthelmintic activity against adult haemonchus contortus. the study aimed to develop an assay with the parasitic adult stage of this species that could be used in conjunction with, or as an alternative to, the free-living larval stage screens commonly used for drug discovery with many parasitic nematode species. the feeding assay showed limitations due to the apparent continuation of a significant ... | 2004 | 15172224 |
| genetic variability in cysteine protease genes of haemonchus contortus. | to increase the existent genetic variability in cysteine proteases, a polymorphism study was performed in haemonchus contortus by comparing 2 different strains of the parasite: north american (na) and spanish (sp) strains. for this purpose, the polymorphism of 5 previously reported genes (ac-1, ac-3, ac-4, ac-5 and gcp-7) were analysed by pcr-sscp and sequencing procedures. based on the sscp results, a total of 20 different alleles were identified for the 5 loci assessed. except locus ac-5, all ... | 2004 | 15180323 |
| interrelationships among physicochemical properties, absorption and anthelmintic activities of 2-desoxoparaherquamide and selected analogs. | the interrelationships between physicochemical properties, absorption and potency of 2-desoxoparaherquamide and five analogs, representing a new anthelmintic class, were evaluated in in vitro and in vivo assays. at ph 7.5, rates of drug absorption by the gastrointestinal nematode haemonchus contortus and jird small intestine, parameterized by the permeability coefficient, p(e), ranged from 1.2-2.4 x 10(-4) cm/min (nematode) to 2.5-5.5 x 10(-3) cm/min (jird). in the jird intestine, absorption was ... | 2004 | 15189303 |
| inheritance of fecal egg count and packed cell volume and their relationship with production traits in sheep infected with haemonchus contortus. | this study describes responses to artificial infection with haemonchus contortus in ewes and lambs of 50% dorset, 25% rambouillet, and 25% finn-sheep ancestry and provides estimates of genetic parameters for measures of parasite resistance. one hundred ninety-eight ewes out of 64 sires, and 386 lambs out of 25 sires were evaluated in autumn and spring of 2 yr. ewes were dewormed shortly after weaning their lambs and lambs were dewormed at about 120 d of age. one week after deworming, ewes and la ... | 2004 | 15216985 |
| the epidemiology of abomasal nematodes of sheep in sweden, with particular reference to over-winter survival strategies. | in may 2002, studies on the seasonal patterns of nematode infection of sheep were undertaken on four commercial sheep farms in southern sweden, which had previously reported problems with nematode parasitism, especially due to haemonchus contortus. one farm was used for intensive investigation. this entailed the establishment of two replicate groups of sheep, each consisting of 20 ewes and their lambs, on adjacent pasture paddocks. the seasonal patterns of nematode infection were followed by reg ... | 2004 | 15219362 |
| novel thiophenes and analogues with anthelmintic activity against haemonchus contortus. | a new series of analogues of 4-(4-fluorophenyl)-2-methylthio-thiophene-3-carbonitrile (1) were synthesized and evaluated for their in vitro and in vivo anthelmintic activity against haemonchus contortus. | 2004 | 15225722 |
| identification of variant abc-transporter genes among onchocerca volvulus collected from ivermectin-treated and untreated patients in ghana, west africa. | treatment with ivermectin (ivm) is known to cause a loss of polymorphism at certain loci of the beta-tubulin, gamma-aminobutyric-acid-receptor, glutamate-gated-chloride-channel and atp-binding-cassette (abc) transporter genes of ivm-resistant haemonchus contortus. the genetic variation of four abc-transporter homologues from onchocerca volvulus was therefore investigated, to determine if any change in genetic polymorphism occurs in these genes following repeated treatment with ivm. samples were ... | 2004 | 15228718 |
| efficacy of eprinomectin pour-on against gastrointestinal nematodes and the nasal bot fly (oestrus ovis) in sheep. | the efficacy of the pour-on formulation of eprinomectin, at a dose rate of 0.5 mg/kg bodyweight, was assessed in sheep against three main species of gastrointestinal nematodes and against the nasal bot fly, oestrus ovis, and some pharmacokinetic parameters were determined for 21 days after the treatment. by comparison with untreated control sheep, infected experimentally with haemonchus contortus, teladorsagia circumcincta and trichostrongylus colubriformis, eprinomectin was 100 per cent effecti ... | 2004 | 15233455 |
| anthelmintic activity of artemisia brevifolia in sheep. | this paper describes the in vitro and in vivo anthelmintic activity of artemisia brevifolia in comparison with levamisole. in vitro studies revealed anthelmintic effects of crude aqueous (cae) and methanol extracts (cme) of artemisia brevifolia (whole plant) on live haemonchus contortus as evident from their paralysis and/or mortality at 6 h post exposure. for in vivo studies, the whole plant of artemisia brevifolia was administered as crude powder (cp), cae and cme at graded doses (1, 2 and 3 g ... | 2004 | 15234763 |
| ivermectin resistant and susceptible third-stage larvae of haemonchus contortus: cholinesterase and phosphatase activities. | cholinesterase and acid phosphatase (ap), but not alkaline phosphatase activities, were detected in cytosolic and membrane-bound fractions of ivermectin resistant and susceptible haemonchus contortus infective-stage larvae. some differences in acetylcholinesterase activity of cytosolic fractions and in the ap activity of these fractions as well as in the response to ap inhibitors by membrane-bound fractions were detected. data are discussed. | 2004 | 15250480 |
| validation of the famacha eye color chart for detecting clinical anemia in sheep and goats on farms in the southern united states. | recent studies on sheep and goat farms in the southern united states indicate that multiple-anthelmintic resistance in haemonchus contortus is becoming a severe problem. though many factors are involved in the evolution of resistance, the proportion of the parasite population under drug selection is believed to be the single most important factor influencing how rapidly resistance develops. therefore, where prevention of resistance is an important parallel goal of worm control, it is recommended ... | 2004 | 15265575 |
| copro-antigen capture elisa for the detection of teladorsagia (ostertagia) circumcincta in sheep: improvement of specificity by heat treatment. | a copro-antigen capture elisa for the detection of teladorsagia circumcincta infection in sheep was developed and evaluated. experiments with faeces from worm-free sheep, that had been spiked with known concentrations of excretory-secretory (e-s) antigen indicated that a positive signal was generated with 180 ng of e-s/ml. a nested design, based on 8 infected and 8 worm-free sheep, was employed to assess the stages during sample preparation contributing to variation in signal from the assay. thi ... | 2004 | 15267118 |
| extracellular matrix: a tool for defining the extracorporeal function of parasite proteases. | the significance of cysteine protease activity present in excretory/secretory products of the feeding stages of haemonchus contortus is discussed here by marcia rhoads and raymond fetterer. based, in part, on the in vitro degradation and uptake of extracellular matrix components by live parasites, they argue that the cysteine proteases have an essential extracorporeal function in the digestion of host tissues. they also outline the merits of the extracellular matrix model, which mimics the in vi ... | 1997 | 15275116 |
| genomic organization of the schistosoma mansoni aspartic protease gene, a platyhelminth orthologue of mammalian lysosomal cathepsin d. | schistosomes are considered the most important of the helminth parasites of humans in terms of morbidity and mortality. schistosomes employ proteolytic enzymes to digest host hemoglobin from ingested human blood, including a cathepsin d-like, aspartic protease that is overexpressed in the gut of the adult female schistosome. because of its key role in parasite nutrition, this enzyme represents a potential intervention target. to continue exploration of this potential, here we have determined the ... | 2004 | 15302411 |
| amphids: the neuronal ultrastructure of macrocyclic-lactone-resistant haemonchus contortus. | the development of anthelmintic resistance by nematode parasites is a growing problem for veterinarians and producers. the intensive use of the macrocyclic lactones for the treatment of a variety of parasitic diseases has hastened the development of resistance to this family of parasiticides among sheep, goats and cattle. as a result, resistance to ivermectin, moxidectin and doramectin by haemonchus contortus has been documented throughout the world. while the exact sites of action of the macroc ... | 2004 | 15305725 |
| an ivermectin-sensitive glutamate-gated chloride channel subunit from dirofilaria immitis. | dirofilaria immitis is a filarial nematode that infects dogs and causes cardiopulmonary disease. the most effective way of controlling the infection is by chemoprophylaxis, using members of the avermectin/milbemycin (a/m) class of anthelmintics, which includes ivermectin; these drugs act at invertebrate glutamate-gated chloride channels (glucl). we have cloned two cdnas encoding d. immitis glucl subunits and demonstrated that at least one may be an important molecular target for the a/ms in vivo ... | 2004 | 15313134 |
| effect of copper oxide wire particles dosage and feed supplement level on haemonchus contortus infection in lambs. | the objective of the experiment was to determine the optimal dose of copper oxide wire particles (cowps) to reduce infection of haemonchus contortus in male lambs. five to six-month-old hair breed lambs were housed on concrete and fed 450 (l; n = 25) or 675 g (h; n = 25) corn/soybean meal supplement and bermudagrass hay. in july, lambs were inoculated with 10,000 l(3) larvae (97% h. contortus; day 0). lambs were administered 0, 2, 4, or 6 g cowp on day 28. concentrations of copper in the liver w ... | 2004 | 15325049 |
| cdna cloning and expression patterns of a peroxiredoxin, a catalase and a glutathione peroxidase from haemonchus contortus. | the range of antioxidant enzyme systems available to haemonchus contortus for detoxification of hydrogen peroxide was investigated using cdna cloning of candidate genes. pcr with primers based on conserved amino acid regions and spliced leader sequences was used to obtain full-length sequences for a 2-cys peroxiredoxin, a catalase, and a selenium-independent glutathione peroxidase, indicating that h. contortus expresses a number of antioxidant systems with the potential to detoxify peroxide (nuc ... | 2004 | 15368124 |
| immunoprotection in goats against haemonchus contortus after immunization with cysteine protease enriched protein fractions. | haemonchus cysteine proteases, because of their apparent critical function in worm physiology, are considered important candidates in the immunological control of haemonchosis in sheep. only limited information is, however, available on the immunoprotective properties of these molecules in goats. in the present study cysteine proteases of haemonchus contortus adult worms isolated from a goat strain (gran canaria, spain) were enriched by affinity chromatography and evaluated as immunoprotective a ... | 2004 | 15369659 |
| evaluation of anthelmintic properties of some plants used as livestock dewormers against haemonchus contortus infections in sheep. | gastrointestinal helminth infections remain a major constraint to livestock production globally. this study evaluated anthelmintic efficacy of 7 plants used as dewormers by farmers and pastoralists in kenya. thus 3 commercial anthelmintics and 7 plant preparations were tested in lambs infected with 5000 or 3000 l3 haemonchus contortus in 4 experiments. in the first experiment, ivermectin, levamisole and albendazole were tested in 46 lambs. seven plant preparations of hagenia abyssinica, olea eur ... | 2004 | 15376783 |
| the effect of supplementary feeding on the resilience and resistance of browsing criollo kids against natural gastrointestinal nematode infections during the rainy season in tropical mexico. | the objective was to determine the effect of supplementary feeding on the resilience and resistance of criollo kids against natural gastrointestinal nematode (gin) infections, when browsing native vegetation during the wet season in tropical mexico. thirty-four 2-month old criollo kids, raised nematode free, were included at weaning in a 22-week trial. the kids were placed into four groups. two groups of 8 kids were offered 100g/day soybean and sorghum meal (26%:74%, respectively fresh basis) (t ... | 2004 | 15381302 |
| mrna sequences for haemonchus contortus intestinal cathepsin b-like cysteine proteases display an extreme in abundance and diversity compared with other adult mammalian parasitic nematodes. | cathepsin b-like cysteine protease (cbl) genes produce the most abundant mrnas ( approximately 16%) detected in the adult female intestine of the parasitic nematode haemonchus contortus. cbl enzymes appear to digest host proteins and are vaccine candidates for immune control of h. contortus and potentially other parasitic nematodes. hence, it is important to quantify the extent of diversity of h. contortuscbl genes. here, expressed sequence tags (ests) were used to assess both the size and diver ... | 2004 | 15383300 |
| observations on the vertical migrations of the third-stage larva of haemonchus contortus (rud.) on experimental plots of lolium perenne s24, in relation to meteorological and micrometeorological factors. | 1950 | 15401178 | |
| genetic resistance to haemonchosis in sheep. | parasitic nematodes cause huge economic losses to the domestic livestock industry. control requires skilled farm management and heavy use of anthelmintics, but breeding for resistant animals has long been held a possibility. for about 20 years after world war ll, the genetics of association between sheep breeds and haemonchus contortus - the main parasite of importance in sheep - was studied in the usa and europe. since the early 1970s, however, such studies have received greater emphasis in aus ... | 1987 | 15462974 |
| development of a vaccine against haemonchus contortus. | haemonchus contortus is an economically important nematode parasite of sheep and the occurrence worldwide of strains resistant to anthelmintic chemicals has emphasized the need to develop a vaccine against it. here, ed munn describes the approach to this problem adopted in his laboratory. the principle developed should be applicable to other gastrointestinal parasites. | 1993 | 15463800 |
| protection studies in sheep using affinity-purified and recombinant cysteine proteinases of adult haemonchus contortus. | vaccination with a membrane-bound thiol sepharose-binding fraction (tsbp) of adult haemonchus contortus has been shown to confer significant levels of protection against homologous challenge in sheep. this fraction is greatly enriched for cysteine proteinase activity. following fractionation of tsbp by anion-exchange chromatography on monoq, protection was found to partition with those fractions further enriched for cysteine proteinase activity. in this study, the cysteine proteinases of adult h ... | 2004 | 15474716 |
| prospect for anthelminthic plants in the ivory coast using ethnobotanical criteria. | sixty plant species were collected in the ivory coast on the basis of an ethnobotanical literature using the following three criteria: activity against worms, diarrhoea and/or abdominal pain. eighty six plant extracts were prepared using 90% ethanol and tested for potential anthelminthic activities with a larvicidal test of haemonchus contortus. 25.6% of the extracts showed a high activity, 12.8% were active or marginally active and the remaining 61.6% were inactive. the fact that a relatively h ... | 2004 | 15507349 |
| total anthelmintic failure to control nematode parasites of small ruminants on government breeding farms in sabah, east malaysia. | government-owned small-ruminant breeding farms in malaysia provide the source of sheep and goats to smallholder farmers in the country. in the eastern malaysian state of sabah, high-level stock losses have been recorded on these farms for several years, frequently accompanied by clinical signs indicating pathogenic levels of infections with the nematode parasite haemonchus contortus. this suggests that their dependence on chemotherapy to control parasite infections had failed. accordingly, tests ... | 2004 | 15509022 |
| a possible model of benzimidazole binding to beta-tubulin disclosed by invoking an inter-domain movement. | although it is well established that benzimidazole (bzms) compounds exert their therapeutic effects through binding to helminth beta-tubulin and thus disrupting microtubule-based processes in the parasites, the precise location of the benzimidazole-binding site on the beta-tubulin molecule has yet to be determined. in the present study, we have used previous experimental data as cues to help identify this site. firstly, benzimidazole resistance has been correlated with a phenylalanine-to-tyrosin ... | 2004 | 15530823 |
| a conserved metalloprotease mediates ecdysis in caenorhabditis elegans. | molting is required for progression between larval stages in the life cycle of nematodes. we have identified four mutant alleles of a caenorhabditis elegans metalloprotease gene, nas-37, that cause incomplete ecdysis. at each molt the cuticle fails to open sufficiently at the anterior end and the partially shed cuticle is dragged behind the animal. the gene is expressed in hypodermal cells 4 hours before ecdysis during all larval stages. the nas-37 protein accumulates in the anterior cuticle and ... | 2004 | 15539494 |
| evaluation of caenorhabditis elegans glycoproteins as protective immunogens against haemonchus contortus challenge in sheep. | high levels of protection can be attained against haemonchus contortus challenge infection in sheep using native antigens isolated from the gut of the adult parasite. however, vaccination with recombinant forms of these antigens, or components thereof, has disappointingly failed to generate similar levels of protection, suggesting that appropriate nematode glycosylation may be a prerequisite for protection. the free-living nematode, caenorhabditis elegans is closely related to h. contortus and h ... | 2004 | 15542095 |
| evidence of p-glycoprotein sequence diversity in cyathostomins. | p-glycoproteins (pgps) are adenosine triphosphate-binding transporter proteins thought to be associated with multi-drug resistance in mammals and protozoans and have been suggested to be involved in the mechanism of ivermectin (ivm) resistance in haemonchus contortus. until now, resistance to ivm has not been reported in cyathostomins in horses in spite of its widespread and frequent use. reasons for this might be differences in the molecular mechanism of the development of resistance. based on ... | 2004 | 15562598 |
| in vitro effects of four tropical plants on three life-cycle stages of the parasitic nematode, haemonchus contortus. | alcoholic extracts of four tropical plants (zanthoxylum zanthoxyloides, newbouldia laevis, morinda lucida and carica papaya) were screened in vitro for potential anti-parasitic effects against eggs, infective larvae and adult haemonchus contortus. significant effects were obtained with all four plants but differences were observed depending on the parasitic stage. the effects of the four plant extracts were similar on egg hatching and were dose dependent. in contrast, no dose-response relationsh ... | 2005 | 15563923 |
| observations of the sheath extension of the third stage, infective larvae of trichostrongylus rugatus. | the length of the sheath extension of third stage (l(3)), infective larvae of trichostrongylus rugatus is reported. the total length and length of the sheath extension of l(3) recovered from the faeces of sheep originating from two localities in south australia were measured. the total length of larvae was 615-722 microm and the length of the sheath extension was 46-56 microm (mean 51.5). the larvae of t. rugatus comprised up to 72% of the larvae recovered. worm free sheep were infected with lar ... | 2004 | 15567044 |
| [use of famacha scoring system as a diagnostic aid for the registration of distinguishing marks in the breeding program for lambs exposed to an experimental haemonchus contortus infection]. | the control of gastro-intestinal nematodes in sheep has almost entirely been based on the use of anthelmintics and pasture management. therefore anthelmintic resistance escalated in the past. one way of reducing this problem may be the limitation of anthelmintic treatment to those animals with clinical symptoms only. the famacha eye-colour-chart is based on the principle knowledge that the colour of mucous membranes are correlated with the anaemiae situation of an animal. to monitor anaemic anim ... | 2004 | 15573778 |
| intestinal dnases of 36 and 38.5kda from the parasitic nematode haemonchus contortus have non-classic dnase characteristics and produce dna fragments with 3'-hydroxyls. | treatment with the anthelmintic fenbendazole induces fragmentation of genomic dna in intestinal cells of haemonchus contortus. this effect is characterized by dna fragments with 3'-hydroxyls (oh). investigation into dnases responsible identified intestinal dnase activities that produce dna fragments with 3'-oh. however, this interpretation was complicated by a mixture of activities in the intestinal fractions evaluated. in addition, intestinal activities displayed non-classic characteristics. he ... | 2004 | 15582511 |
| genomic organization and expression analysis for hcstk, a serine/threonine protein kinase gene of haemonchus contortus, and comparison with caenorhabditis elegans par-1. | the organization and expression of a putative serine/threonine kinase gene (designated hcstk), proposed to relate to a conserved eukaryotic signal transduction pathway, was characterized for the socio-economically important pathogen haemonchus contortus (nematoda). the entire hcstk gene is approximately 26.7 kb in size, has 26 exons and is inferred to produce multiple isoforms via alternative splicing in its n-terminal header and spacer domains. comparison of hcstk with its caenorhabditis elegan ... | 2004 | 15588586 |
| the failure of haemonchus contortus excretory/secretory products to stimulate gastrin secretion in vitro. | excretory/secretory (es) products collected from exsheathed l3 or parasitic stages of haemonchus contortus were tested in vitro for gastrin stimulatory properties using an ovine abomasal antral mucosal preparation. in addition, the motility of exsheathed l3 and parasites recovered on weeks 2, 6 and 8 post-infection was studied in water, saline, saline with glucose or ovine blood and in hbss ph 2.5-7.4. parasitic stages became immotile rapidly in water and hbss ph 2.5, more slowly in hbss ph 3.5, ... | 2004 | 15611860 |
| genetic variability of glutamate-gated chloride channel genes in ivermectin-susceptible and -resistant strains of cooperia oncophora. | the glutamate-gated chloride channels (glucls) are members of the ligand-gated ion channel superfamily that are thought to be involved in the mode of action of ivermectin and mechanism of resistance. using reverse-transcriptase pcr techniques, 2 full-length glucl cdnas, encoding gluclalpha3 and gluclbeta subunits, were cloned from cooperia oncophora, a nematode parasite of cattle. the two sequences show a high degree of identity to similar subunits from other nematodes. the c. oncophora gluclalp ... | 2004 | 15648697 |
| evaluation of copper supplementation to control haemonchus contortus infections of sheep in sweden. | a pen study was conducted to assess the effect of providing daily copper mineral supplement, or copper wire particle (cowp) capsules, on established or incoming mixed nematode infections in young sheep. for lambs with established (6 week old) infections, cowp resulted in 97% and 56% reduction of the adult and early l4 stages of h. contortus, respectively, compared with controls (p<0.001). additionally there was a 74% reduction in teladorsagia circumcincta infections in the cowp lambs compared wi ... | 2004 | 15663075 |
| increased resistance to anthelmintics of haemonchus contortus eggs associated with changes in membrane fluidity of eggshells during embryonation. | the embryonation of nematode eggs has been shown to increase their resistance to anthelmintics when parasites are submitted to egg hatch assays. nevertheless, no mechanism has been suggested to explain this phenomenon. earlier observations by other authors showed that the biochemical composition of eggshells is altered during the embryonation of eggs. the functional consequences of these changes have not been identified. we studied the changes in membrane environment (eggshells) of haemonchus co ... | 2005 | 15678352 |
| evaluation of the phenotypic performance of a red maasai and dorper double backcross resource population: indoor trickle challenge with haemonchus contortus. | six f(1) dorper (d) x red maasai (r) rams were mated to both d and r ewes to produce backcross lambs. these six double backcross resource families are being analysed to identify quantitative trait loci that may be controlling resistance to gastro-intestinal (gi) nematode parasites, mainly haemonchus contortus. after assessing the phenotypic performance of the lambs following exposure to natural infections, the surviving lambs were drenched and moved indoors for an artificial challenge with h. co ... | 2004 | 15710527 |
| effects of the repeated distribution of sainfoin hay on the resistance and the resilience of goats naturally infected with gastrointestinal nematodes. | due to the high prevalence of anthelmintic resistance in goats, the need to explore novel approaches to control nematodes and to reduce the exclusive reliance on chemotherapy is strongly demanded in this host species. in sheep, several studies have shown that the consumption of tannin-rich legume forages was associated with positive effects on host resilience and resistance to parasite infection. in goats, studies on such interactions between tanniferous plants and nematode infections remain few ... | 2005 | 15710528 |
| characterization of haemonchus contortus calreticulin suggests its role in feeding and immune evasion by the parasite. | haemonchus contortus, a gastrointestinal parasite of sheep and goat feeds on the blood of its host and causes bleeding at the biting site. in this report, we demonstrate that the ca2+ binding protein, calreticulin (calr), is present in excretory/secretory products of adult worms. the secreted calr enhanced plasma coagulation time. using recombinant fragments, this property has been mapped to c-terminal part of the molecule which has binding sites for ca2+ as well as clotting factors. complement ... | 2005 | 15716049 |
| excretory/secretory products of sheep abomasal nematode parasites cause vacuolation and increased neutral red uptake by hela cells. | excretory/secretory (es) products of ostertagia (teladorsagia) circumcincta and haemonchus contortus have been implicated in the inhibition of gastric acid secretion and vacuolation, and the loss of parietal cells associated with abomasal parasitism. vacuolation of epithelial (hela) cells caused by adult o. circumcincta or l3 o. circumcincta or h. contortus es products have been examined by differential interference contrast microscopy and by the neutral red uptake assay. es products caused visi ... | 2005 | 15723269 |
| the modulatory influence of trypanosoma brucei on challenge infection with haemonchus contortus in nigerian west african dwarf goats segregated into weak and strong responders to the nematode. | although nigerian west african dwarf (wad) goats are relatively resistant to infection with haemonchus contortus and are also trypanotolerant, natural outbreaks of both infections are known to occur. despite their relative resistance to h. contortus wad goats nevertheless show variability in response phenotype and it was of interest to examine the effect of this variability on the outcome of concurrent trypanosome infection. trypanosoma brucei infections were established in goats that were initi ... | 2005 | 15725530 |
| characterization of moxidectin resistant trichostrongylus colubriformis and haemonchus contortus. | the development of moxidectin resistance (mox-r) in sheep parasitic gastrointestinal nematodes already carrying multiple resistances to other anthelmintic groups has made control of these strains very difficult. the anthelmintic resistance patterns of mox-r strains of trichostrongylus colubriformis and haemonchus contortus were characterized to provide an insight into the remaining role of anthelmintics in the control of such strains. homozygous mox-r individuals of both genera were unaffected b ... | 2004 | 15725536 |
| relationship of abomasal histology and parasite-specific immunoglobulin a with the resistance to haemonchus contortus infection in three breeds of sheep. | this study was carried out to evaluate the relationship of abomasal inflammatory cells and parasite-specific immunoglobulin a (iga) in mucus, with the resistance to haemonchus contortus infection in three breeds of sheep naturally infected with gastrointestinal nematodes. the breeds were the native santa ines sheep, and the european suffolk and ile de france breeds. mast cells, eosinophils and globule leucocytes were enumerated in abomasal mucosa. eosinophils within the sub-mucosa also were coun ... | 2004 | 15725538 |
| effect of urea-molasses block supplementation on grazing weaner goats naturally infected with gastrointestinal nematodes. | the influence of feeding urea-molasses blocks (umb) on growth and gastrointestinal (gi) nematode parasitism of weaner goats grazing the same pasture was investigated on a farm in nyandarua district, kenya. thirty female small east african goat kids at an average age of 5 months were initially treated with albendazole orally (5 mg kg(-1) body mass) and randomly assigned into one of two groups: group i were fed umb prepared using a cold process and group ii kids (controls) received no block supple ... | 2004 | 15732455 |
| haemonchus contortus egg excretion and female length reduction in sheep previously infected with oestrus ovis (diptera: oestridae) larvae. | mixed parasitic infection of animals is a common phenomenon in nature. the existence of one species often positively or negatively influences the survival of the other. our experimental study was started with the objectives to demonstrate the interaction of haemonchus contortus and oestrus ovis in relation to cellular and humoral immune responses in sheep. twenty-two sheep of tarasconnais breed (france) were divided into four groups (o, oh, h and c) of five or six animals. group o and oh receive ... | 2005 | 15740864 |
| multiple anthelmintic resistance in haemonchus contortus isolated from south african boer goats in switzerland. | a suspected case of multiple anthelmintic resistance on a farm in the canton of zurich, switzerland, into which south african boer goats had previously been imported, was confirmed in a controlled test. twenty sheep were allocated into one control group and three treatment groups to determine the efficacy of mebendazole, ivermectin and moxidectin applying the faecal egg count reduction test (fecrt). the sheep were slaughtered 1 week later and post-mortem worm counts were performed. benzimidazole ... | 2005 | 15740865 |
| effect of ivermectin on feeding by haemonchus contortus in vivo. | while several in vitro studies have shown that the anthelmintic ivermectin inhibits feeding by parasites, the relevance of this putative site of action in vivo has not been demonstrated. for this study, techniques to measure feeding by haemonchus contortus in vivo relied on the blood feeding characteristics of the worm, and utilised tritiated inulin administered to sheep intravenously and subsequently measured in worms recovered from abomasa. nematodes recovered from sheep treated with ivermecti ... | 2005 | 15740872 |
| in vivo effects of fagara leaves on sheep infected with gastrointestinal nematodes. | infections of the gastrointestinal tract with parasitic nematodes, and particularly haemonchus contortus, represent one of the main pathological constraints on the breeding of small ruminants in tropical countries. owing to the constant development of anthelmintic resistance in worm populations, alternative control methods are being evaluated, including an assessment of the value of the traditional plants. the effect of the consumption of fagara leaves on sheep infected with gastrointestinal nem ... | 2005 | 15747857 |
| investigations on the seasonal patterns of strongyle infections in grazing lambs, and the occurrence of anthelmintic resistance on sheep and goat farms in western anatolia, turkey. | the seasonal patterns of strongyle infections in untreated, weaned lambs were determined on four governmental farms during a grazing season. in three farms, the infection level (predominantly teladorsagia spp. and trichostrongylus spp.) measured by egg counts or worm burdens remained low throughout the study; higher egg counts mainly caused by haemonchus contortus were transiently recorded on the fourth farm. significant body weight gains were observed in all groups, but they varied between farm ... | 2005 | 15765247 |
| isolation and characterisation of a beta tubulin isotype 2 gene from two species of cyathostomin. | this study describes the isolation and characterisation of beta tubulin isotype 2 cdna sequences from two common species of cyathostomin, cylicocyclus nassatus and cyathostomum catinatum. the full-length cdnas for these species were 1709 and 1753 bp in length, respectively, including 1350 bp of sequence inferred to encode 450 amino acids of peptide sequence. they had greatest identity with previously characterised isotype 2 sequences from trichostrongylus colubriformis, cooperia oncophora and ha ... | 2005 | 15777911 |
| efficacy of two cyclooctadepsipeptides, pf1022a and emodepside, against anthelmintic-resistant nematodes in sheep and cattle. | resistance against the major currently available anthelmintics has reached a critical level in many small ruminant herds world-wide, and is increasingly becoming a problem in horses and cattle. therefore, new products with different modes of action are urgently needed. recently, such a new class of compounds, the anthelmintically active cyclooctadepsipeptides, was described. here, the effects of cyclooctadepsipeptides on benzimidazole-, levamisole- and ivermectin-resistant populations of haemonc ... | 2005 | 15796017 |
| presence of the ldnf glycan on the host-protective h-gal-gp fraction from haemonchus contortus. | immunization of sheep with the gut membrane-associated protein complex h-gal-gp of adult haemonchus contortus induces high levels of protection against a homologous challenge infection. protection is correlated with a systemic igg response against the antigen. analysis of the antibody response showed that the majority of the antigen-specific igg was of the igg2 isotype. a substantial proportion (74%) of this response was directed against the glycan component of h-gal-gp. the high immunogenicity ... | 2005 | 15813723 |
| the possibilities and limitations of evasive grazing as a control measure for parasitic gastroenteritis in small ruminants in temperate climates. | between 1999 and 2003 studies were done at utrecht university on the population dynamics of gastrointestinal nematodes and the potential to use evasive grazing for the control of nematode infections in small ruminants. on most pastures grazed in may and june it took at least 3 weeks before high pasture infectivity levels for haemonchus contortus developed while it took at least 2 weeks on pastures grazed in july, august and september. occasionally, larvae emerged earlier on pasture when high tem ... | 2005 | 15817209 |
| characterisation of the two most abundant genes in the haemonchus contortus expressed sequence tag dataset. | analysis of the haemonchus contortus expressed sequence tag (est) dataset revealed that almost 10% of all ests (1719 ests) belong to a family of related genes. close analysis of the ests suggests that these represent two genes (called here hc-nim-1 and hc-nim-2) with multiple alleles of each. these genes show significant similarity to two genes from caenorhabditis elegans, f54d5.3 (wormbase accession wbgene00010049, corresponding protein wp:ce28033) and f54d5.4 (wbgene00010050, wp:ce03409) of un ... | 2005 | 15826643 |
| persistent efficacy of doramectin against haemonchus contortus in goats. | 2005 | 15828727 | |
| molecular and biochemical characterization of a protein cyclophilin from the nematode haemonchus contortus( p ). | we have cloned, sequenced and expressed a gene of haemonchus contortus that encodes a protein (termed hccyp) consisting of a cyclophilin domain and an rna recognition motif (rrm). an antiserum raised against the recombinant protein showed that hccyp was present in the insoluble fraction (mostly nuclear) of the parasite homogenate. the recombinant protein possessed the typical cis-trans peptidyl-prolyl isomerase activity of cyclophilins and this activity was inhibited by the immunosuppressant cyc ... | 2005 | 15830208 |
| characterization of proteinases in different isolates of adult haemonchus contortus. | a high degree of intra- and inter-geographical variation has been demonstrated previously in the excretory/secretory proteinases released by adult haemonchus contortus. proteinase activity has also been associated with host-protective 'hidden' antigens isolated from the gut of adult h. contortus. if similar geographical strain variation also exists within the gut-associated proteinases, this will have important implications for the development of a globally effective vaccine. the proteinases act ... | 2005 | 15830817 |
| synthesis and anthelmintic activity of 7-substituted 3,4a-dimethyl-4a,5a,8a,8b-tetrahydro-6h-pyrrolo[3',4':4,5]furo[3,2-b]pyridine-6,8(7h)-diones. | the racemic 7-substituted 3,4a-dimethyl-4a,5a,8a,8b-tetrahydro-6h-pyrrolo[3',4':4,5]furo[3,2-b]pyridine-6,8(7h)-diones represent novel tricyclic compounds with strong in vivo efficacy against the parasitic nematode haemonchus contortus rudolphi in sheep. here we report on the synthesis of tricyclic endo-2,3-dihydro[3,2-b]pyridine-type cycloadducts and describe the separation of the racemic 3,4a-dimethyl-7-ethyl-4a,5a,8a,8b-tetrahydro-6h-pyrrolo[3',4':4,5]furo[3,2]pyridine-6,8(7h)-dione into the ... | 2005 | 15837328 |
| real time pcr for the diagnosis of benzimidazole resistance in trichostrongylids of sheep. | this report describes a new molecular method for the diagnosis of benzimidazole susceptibility or resistance in three main species of trichostrongylids of sheep (haemonchus contortus, teladorsagia circumcincta and trichostrongylus vitrinus). this assay is based on the use of real time polymerase chain reaction (pcr) to detect mutations of residue 200 on isotype 1 of beta-tubulin. the technique allows calculation of the proportion of each allelic variant as it combines kinetic (real time quantita ... | 2005 | 15845285 |
| rapid selection for ivermectin resistance in haemonchus contortus. | lambs infected with two isolates, one british and one american, of haemonchus contortus were treated with increasing doses of ivermectin. eggs from the highest dose that had not eliminated the infection were cultured and larvae used to infect another lamb. after three generations the h. contortus was resistant to 0.2 mg/kg ivermectin. the results stress the ease with which ivermectin resistance can be selected if high selection pressure is applied. | 2005 | 15845291 |
| studies on the spring rise phenomenon in ovine helminthiasis. i. spring rise in stabled sheep. | serial ova count studies were conducted to determine some of the characteristics of the spring rise in faecal shedding of nematode ova by parasitized sheep in flocks in the montreal area. it was discovered that substantial spring rises occurred in most ewes following their lambing but that great variation existed in the magnitude, duration, and pattern of the rises. although rams did not display increased ova counts, a slight but well-defined rise developed in one unbred ewe. larval studies in e ... | 1968 | 15846886 |
| immunolocalisation of an abc transporter, p-glycoprotein, in the eggshells and cuticles of free-living and parasitic stages of haemonchus contortus. | recent data have suggested that p-glycoprotein (pgp), working as membrane efflux "pumps", plays a major role in the transport of anthelmintic drugs in parasitic nematodes of ruminants. flow cytometry analyses has shown that active pgp is probably present in the external layers of haemonchus contortus eggshells, following staining with the mouse monoclonal anti-human mdr1 antibody uic2, which binds to pgp in its active conformation. we evaluated the presence and distribution of this protein in th ... | 2005 | 15856301 |
| new oral linguiform projections and their associated neurons in the third-stage infective larva of the parasitic nematode oesophagostomum dentatum. | the infective larvae (l3i) of the nematode parasite of swine, oesophagostomum dentatum, are passively ingested by their hosts. the l3i exhibit certain behaviors that are probably selected to increase the likelihood of ingestion, by strategic positioning in the environment. the larvae show positive geotactic behavior and respond to temperature variations in their environment, as shown by their behavior on a thermal gradient. to investigate neuronal control of this behavior, we initiated a study o ... | 2005 | 15856873 |
| the predatory capability of arthrobotrys cladodes var. macroides in the control of haemonchus contortus infective larvae. | one hundred compost samples were examined for the presence of nematophagous fungi on the sheep farms of mazanderan, province, iran. arthrobotrys cladodes var. macroides (iran 677c=cbs 143565) was isolated from 3% of the samples examined. nematophagous activity of this fungus which was shown for the first time in this study, revealed the addition of 1000, 8000, 20000 and 100000 conidia per gram of feces of sheep reduced significantly (p<0.001) the number of haemonchus contortus infective larvae i ... | 2005 | 15899553 |
| protection induced by vaccinating sheep with a thiol-binding extract of haemonchus contortus membranes is associated with its protease components. | previous work has shown that a protein extract enriched for cysteine protease activity (tsbp) prepared from adult haemonchus contortus using thiol sepharose affinity chromatography confers substantial protection against a single challenge infection. tsbp comprised proteases and other proteins. here, tsbp were further fractionated using anion-exchange chromatography and fractions pooled on the basis of containing (1) protease activity, (2) a prominent non-protease peptide and (3) material which d ... | 2005 | 15910420 |
| effects of excretory/secretory products of haemonchus contortus on cell vacuolation. | excretory/secretory (es) products of the gastric nematode, haemonchus contortus, have been implicated in the inhibition of gastric acid secretion which follows infection. parietal cell vacuolation has been observed in abomasal sections from parasitised sheep, and es prepared in vitro has been reported to cause vacuolation and to increase neutral red (nr) uptake in epithelial cell cultures. we have used the latter approach to examine, at the cellular level, the effects of es prepared from l3 and ... | 2005 | 15918071 |
| impact of the nematophagous fungus duddingtonia flagrans on muellerius capillaris larvae in goat faeces. | the small lungworm muellerius capillaris is very prevalent in goats and causes production losses. its control is particularly difficult. the nematophagous fungus duddingtonia flagrans has been shown to be effective in trapping a large range of gastro-intestinal nematode larvae but its trapping activity against small lungworm remains to be assessed. the purpose of this work was firstly, to evaluate the ability of first-stage larvae of m. capillaris (l1) to induce trap formation in in vitro condit ... | 2005 | 15936150 |
| cloning and characterization of a novel immunogenic protein 3 (nip3) from brugia malayi by immuno screening of a phage-display cdna expression library. | iterative screening of a phage display cdna expression library of the third-stage larvae (l3) of brugia malayi with sera from putatively immune individuals (endemic normal, en) identified a novel clone with insert showing significant homology to onchocerca volvulus novel immunogenic protein-3 (ov-nip3) gene and caenorhabditis elegans nip3-like protein and hence the gene was designated brugia malayi nip3-like protein (bmnip3). est database analysis showed that ests from several gastrointestinal n ... | 2005 | 15952042 |
| toxicity of bacillus thuringiensis to parasitic and free-living life-stages of nematode parasites of livestock. | a collection of bacillus thuringiensis (bt) strains (bts) were screened for activity against the free-living larval stages of nematode parasites of livestock. two strains were identified with significant activity in inhibiting larval development of haemonchus contortus, trichostrongylus colubriformis and ostertagia circumcincta. these strains were also toxic to the adult parasitic stages of these nematode species in vitro. adult h. contortus and o. circumcincta showed complete cessation of movem ... | 2005 | 15964574 |
| production of eosinophil chemoattractant activity by ovine gastrointestinal nematodes. | eosinophilia is a well documented feature of helminth infections but the precise nature of the interaction between parasite and eosinophil remains an enigma. this paper describes experiments demonstrating that ruminant gastrointestinal trichostrongyles produce potent chemoattractant activity for ovine bone marrow-derived eosinophils in vitro. this activity was initially identified as a constituent of whole worm extracts of third and fourth larval (l3, l4), and adult stages of teladorsagia circum ... | 2005 | 15982478 |
| an evaluation of serial analysis of gene expression (sage) in the parasitic nematode, haemonchus contortus. | this study evaluated a relatively new molecular technique, serial analysis of gene expression (sage), as a tool for quantifying gene expression in the ovine abomasal nematode haemonchus contortus for which there is relatively limited (approximately 20% gene coverage) sequence information. sage technology generates data that are both qualitative and quantitative and, as such, compliments other functional genomics approaches such as est analysis and micro-array. prior to embarking on large-scale c ... | 2005 | 15991498 |
| consequences of the unusually warm and dry summer of 2003 in the netherlands: poor development of free living stages, normal survival of infective larvae and long survival of adult gastrointestinal nematodes of sheep. | during 2003 a grazing study was performed at utrecht university to evaluate evasive grazing and application of duddingtonia flagrans for the control of parasitic gastroenteritis in sheep. however, the summer of 2003 (june-august) was unusually warm and dry. as a result the patterns of gastrointestinal nematode infections deviated from those observed in more average years. the proportion of eggs that developed to infective larvae was far lower than normal in july-august. on the other hand, surviv ... | 2005 | 16009492 |
| anthelmintic resistance survey in new zealand. | the prevalence and level of thiabendazole resistance of sheep nematodes in the north island of new zealand was investigated by means of an in vitro egg-hatch technique; samples from sheep on 52 properties in six country areas were examined. resistance of haemonchus contortus and trichostrongylus spp. was identified on the basis of egg hatch in 0.1 ppm thiabendazole. evidence of resistance was obtained on 11(21.2%) of the properties. ld 50's and resistance ratios were calculated for the resistant ... | 1982 | 16030902 |
| a strain of haemonchus contortus resistant to thiophanate. | the occurrence of a field strain of haemonchus contortus resistant to thiophanate is reported for the first time in new zealand. in a controlled anthelmintic trial with experimentally infected animals, thiophanate at 50-100 mg/kg had no appreciable effect on the haemonchus burden. albendazole reduced faecal strongylate egg counts by 95% in animals with naturally acquired 59 infections. | 1985 | 16031158 |
| the persistence of the anthelmintic activity of ivermectin in sheep. | the persistent anthelmintic effect of subcutaneously and orally administered ivermectin given at a dose rate of 0.2 mg/kg was evaluated against experimentally induced infections of haemonchus contortus, ostertagia spp., trichostrongylus spp. and cooperia curticei in sheep. while both ivermectin treatments apparently resulted in some reduction in the establishment of most of the parasite species examined, only for c. curticei were these reductions statistically significant. for c. curticei, stati ... | 1986 | 16031290 |
| non-confirmation of anthelmintic resistance in ostertagia spp. | an investigation was undertaken to confirm the existence of a mebendazole-resistant strain of ostertagia spp. on a ram-breeding property in taihape. the results indicated that while a strain of haemonchus contortus from this farm was highly resistant to mebendazole, an isolate of ostertagia spp. was fully susceptible. possible reasons for the discrepancy between previous and present findings are briefly discussed. | 1986 | 16031304 |
| the comparative efficacy of four broad spectrum anthelmintics against some experimentally induced trichostrongylid infections in sheep and goats. | a controlled slaughter trial was undertaken to compare the efficacies of oxfendazole (5 mg/kg), morantel citrate (10 mg/kg), levamisole (8 mg/kg) and ivermectin (0.2 mg/kg) against experimentally induced infections of adult haemonchus contortus, ostertagia spp., trichostrongylus colubriformis and cooperiacurticei in sheep and goats. ivermectin and oxfendazole achieved similar levels of efficacy in both hosts against all four worm genera as did levamisole and mortantel against h. contortus and c. ... | 1987 | 16031344 |
| removal of haemonchus contortus, ostertagia circumcincta and trichostrongylus spp. from goats, by morantel citrate, levamisole hydrochloride, fenbendazole, and oxfendazole. | young feral goats harbouring 3, 7 and 36 day old experimental infections of strains of gastrointestinal nematodes, known to be susceptible to anthelmintics in sheep, were dosed orally with commercially available anthelmintics at the manufacturers' recommended rates for sheep. the drugs and overall removals of ostertagia circumcincta and trichostrongylus spp. (t. colubriformis and t. vitrinus) respectively were: morantel citrate 69% and 68%; levamisole hydrochloride 55% and >99%; fenbendazole 98. ... | 1987 | 16031353 |
| the efficacy of albendazole against some gastrointestinal nematodes in goats. | on the basis of worm counts in naturally infected angora-x goats, albendazole at either 3.8 mg/kg repeated after 24 hours or as a single dose at 7.6 mg/kg, was >99% effective in removing adult ostertagia and trichostrongylus spp. small numbers of adult haemonchus contortus, cooperia sp. and chabertia ovina were present in control but not treated animals. the single dose of 7.6 mg/kg removed >99% of adult oesophagostomum venulosum whereas the repeated dose of 3.8 mg/kg removed only 96%. | 1988 | 16031461 |
| failure of young goats to acquire resistance to haemonchus contortus. | two experiments were carried out to investigate the acquisition by goats of resistance to haemonchus contortus. in experiment 1, five saanen wethers reared worm-free and averaging 5 1/2 months of age at the start of the experiment, were dosed with 200 h. contortus infective larvae three times per week for 10 weeks (approximately 23 infective larvae/kg mean initial liveweight/week) and then given anthelmintic treatment. each goat and an equal number of worm-free controls were then challenged with ... | 1989 | 16031502 |
| multigeneric resistance to benzimidazole anthelmintics in sheep. | benzimidazole resistance involving several gastrointestinal nematode genera on a single sheep farm in new zealand is reported for the first time. a controlled slaughter trial showed that at the recommended dose rate of 12.5 mg/kg, mebendazole had efficacies of 0, 60, 66, 90, 54 and 38% against haemonchus contortus, ostertagia spp., nematodirus spp., intestinal trichostrongylus spp., strongyloides spp. and oesophagostomum venulosum, respectively. the relevance of such multigeneric resistance to p ... | 1989 | 16031521 |
| an evaluation of an oral formulation of moxidectin against selected anthelmintic-resistant and -susceptible strains of nematodes in lambs. | the efficacy of an oral formulation of the newly developed parasiticide, moxidectin, was tested against benzimidazole-resistant haemonchus contortus, trichostrongylus colubriformis, and nematodirus spathiger, levamisole-resistant ostertagia circumcincta, and susceptible cooperia curticei infections in weaned lambs. thirty-two lambs were experimentally infected with mixed doses of the above strains of nematodes. they were allocated into four treatment groups by stratified randomisation using live ... | 1992 | 16031668 |
| efficacy of a topical formulation of eprinomectin against endoparasites of cattle in new zealand. | two controlled studies involving 24 cattle were conducted in new zealand to determine the efficacy of a topical, non-flammable formulation of eprinomectin against induced and naturally acquired nematode infections. in trial 1, nematode infections were induced on day -5 with third-stage larvae of cooperia spp., haemonchus contortus, ostertagia ostertagi and trichostrongvlus colubriformis so that the nematodes would be at the fourth larval stage when the cattle were treated. in trial 2, cattle had ... | 1997 | 16031938 |
| resistance to macrocyclic lactone anthelmintics by haemonchus contortus and ostertagia circumcincta in sheep in new zealand. | to establish the efficacy of oral formulations of ivermectin and moxidectin against naturally acquired abomasal nematode infections on a north island sheep farm. | 2001 | 16032171 |