Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| repeatability of ovine faecal egg counts and blood packed cell volumes in haemonchus contortus infections. | 1987 | 3583550 | |
| the anthelmintic efficacy of netobimin against naturally acquired gastrointestinal nematodes in sheep. | the broad-spectrum anthelmintic efficacy of netobimin (sch 32481, schering corporation) was evaluated using 30 cross-bred spring lambs with naturally acquired infections of gastrointestinal nematodes. three groups of 10 animals each were allotted into either control (given a tap water drench as a placebo) or 7.5 and 20 mg kg-1 dosage groups (given the netobimin as an oral drench). seven to fourteen days post-treatment, animals were necropsied and nematodes recovered by standard techniques. exami ... | 1987 | 3439008 |
| changes in lipids and free fatty acid fractions in adult haemonchus contortus during incubation in vitro. | adult haemonchus contortus (rud., 1803) has been investigated for its ability to utilize lipids with regard to the total lipids, sterols, free fatty acids, acylglycerols and phospholipids produced during incubation in vitro. all these components exhibit extensive fluctuations, decreasing at some times and increasing at others, thus indicating both biosynthesis and utilization. also, changes in fatty acid components of total lipids have been analyzed by gas liquid chromatography. these observatio ... | 1987 | 3564346 |
| partial protection of lambs against haemonchus contortus by vaccination with a fractionated preparation of the parasite. | florida native lambs, less than 6 months of age, were successfully vaccinated against haemonchus contortus with a high mol. wt fraction (greater than 30,000 daltons) derived from a somatic extract of h. contortus larvae (sel) and excretions and secretions (es) of larvae isolated during in vitro development from the infective 3rd to 4th stage. a 59% reduction in adult worm numbers was obtained in vaccinates compared to naive lambs following challenge. the protection in vaccinated lambs was simila ... | 1987 | 3564350 |
| comparison of ivermectin and thiabendazole for treatment of naturally occurring nematode infections of goats in kenya. | the anthelmintic activity of thiabendazole (tbz) at 88 mg kg-1 and ivermectin at 0.2 mg kg-1 was examined in goats with naturally-acquired nematode infections. in one experiment, a herd of 450 does was treated with tbz or ivermectin at 4-week intervals for 9 months and efficacy was measured by reduction in faecal egg counts after each treatment. in a second experiment, 100 kids were treated with ivermectin and effectiveness measured at 2 and 4 weeks after treatment by comparison of their egg cou ... | 1987 | 3564349 |
| vaccination of young lambs by means of a protein fraction extracted from adult haemonchus contortus. | lambs aged 48-150 days which had been injected with extracts enriched in a functional antigen (contortin) obtained from adult haemonchus contortus developed specific circulating antibodies and were less susceptible to haemonchosis when challenged 1 month later with a single dose of 20,000-25,000 infective 3rd-stage larvae. sera from 18 out of a total of 19 lambs injected with the extract contained precipitating antibodies to 2-5 components of the extract. none of these lambs died. the one extrac ... | 1987 | 3588016 |
| epidemiology of gastrointestinal nematodes of sheep and goats in haryana, india. | epidemiological studies on some gastrointestinal nematodes of sheep and goats in karnal, ambala and rohtak districts of haryana (india) revealed that haemonchus contortus and trichostrongylus spp. were responsible for parasitic gastroenteritis in these hosts. the adult parasites persisted in the host throughout the year and there was no indication of hypobiosis. the maintenance of the parasite population depended on a continuous cycle of infection between the host and the pasture. the agroclimat ... | 1987 | 3590608 |
| systemic release of a mast cell proteinase following nematode infections in sheep. | an enzyme-linked immunosorbent assay (elisa) for sheep mast cell proteinase (smcp) has been developed. concentrations of smcp in homogenates of abomasal tissue from parasite-immune sheep (341 micrograms smcp/g tissues) were raised when compared to those in normal (non-infected) abomasa (0.145 micrograms smcp/g tissue). smcp was not detected in sera from normal animals challenged with haemonchus contortus but was present (less than 1.0 ng smcp/ml) in sera from 8/11 immune sheep 2 h after intra-ab ... | 1987 | 3479741 |
| efficacy of levamisole and netobimin against haemonchus contortus in lambs in louisiana. | efficacy of levamisole was evaluated in a suspected levamisole-resistant population of haemonchus contortus in the louisiana state university sheep flock. the efficacy of netobimin also was evaluated against this population of haemonchus. in trial 1, 5 lambs naturally infected with h contortus were given 8 mg of levamisole/kg of body weight as a drench, and 5 lambs were not treated (controls). nematode recovery after slaughter indicated 0% efficacy against h contortus. in trial 2, 30 nematode-fr ... | 1987 | 3662209 |
| haemonchus contortus resistance to ivermectin. | 1987 | 3681886 | |
| [benzimidazole-resistant haemonchus contortus in sheep in west germany]. | 1987 | 3593194 | |
| efficacy of fenbendazole-medicated feed blocks against gastrointestinal nematode infections in calves. | an anthelmintic trial was conducted to determine the efficacy of fenbendazole (fbz) incorporated into two types of feed blocks given daily for 3 or 10 days to calves naturally parasitized with gastrointestinal nematodes. each treated calf consumed 5 mg of fbz/kg of body weight. the fbz was greater than 99% effective in removing adults of haemonchus contortus, ostertagia ostertagi, o lyrata, cooperia punctata, c pectinata, c onchophora, trichostrongylus axei, bunostomum phlebotomum, and oesophago ... | 1987 | 3605803 |
| physiological and microbiological changes in the abomasum of sheep infected with large doses of haemonchus contortus. | the ph, po2 and the number of viable bacteria per ml of abomasal fluid were recorded before and after administering large doses of infective larvae of h. contortus to sheep. highly significant increases were observed in the ph, in numbers of viable bacteria and in the proportion of oxygen-sensitive bacteria in the abomasal fluid during the first 10 to 14 days of infection. at the same time a decrease in the abomasal fluid po2 was recorded. subsequently a slow recovery of ph, po2 and bacterial nu ... | 1987 | 3611432 |
| changes in lc50 in an in vitro egg development assay during the patent period of haemonchus contortus in sheep. | using an in vitro egg development assay with thiabendazole as anthelmintic the lc50 of eggs produced by two sheep infected with either a susceptible or a resistant strain of haemonchus contortus was followed during the patent period from 22 days to 77 days after infection. in both sheep the lc50 followed the same pattern. at the start of the patent period the average values for the susceptible and the resistant strain were, respectively, 0.05 and 0.21 micrograms ml-1 thiabendazole, after 40 to 6 ... | 1987 | 3616153 |
| the pathogenicity of haemonchosis in sheep and goats in iraq: 1. clinical, parasitological and haematological findings. | the response of awassi sheep and the local breed of iraqi goats to primary infection with a prevalent trichostrongylid nematode, haemonchus contortus, was compared by examining their worm burden and the pathogenic effects of the parasite on these hosts following experimental infection. the results showed that the goats had lower worm burdens and had suffered less severe clinical and haematological disturbances than the awassi sheep. the worm counts in sheep were higher than in goats but the coun ... | 1987 | 3617428 |
| detecting in vitro anthelmintic effects with a micromotility meter. | an in vitro target parasite anthelmintic assay utilizing a micromotility meter has been developed and validated. haemonchus contortus, an economically important ruminant helminth with worldwide distribution, was the parasite used in the model. four commercially available ruminant anthelmintics (albendazole, ivermectin, levamisole hydrochloride and coumaphos) were initially evaluated at concentrations of 200, 150, 100 and 50 micrograms ml-1. all four significantly affected helminth motor activity ... | 1987 | 3617429 |
| prevalence of benzimidazole resistance of nematodes in sheep in the netherlands. | a survey was carried out in the netherlands to determine the prevalence of benzimidazole resistance in sheep nematodes. it was shown that 47 per cent of the 59 investigated flocks harboured trichostrongylid populations with resistance to benzimidazoles, as demonstrated by an ld50 value of 0.12 micrograms ml-1 thiabendazole or higher in an in vitro egg hatch assay. on these farms haemonchus contortus was found to be the dominant species. in two flocks resistant ostertagia and, or, trichostrongylu ... | 1987 | 3628978 |
| development and survival of haemonchus contortus larvae on pasture in iraq. | the survival of haemonchus contortus infective larvae on pasture and soil was studied over a period of 12 months in the baghdad area. infective larvae were found on herbage and soil at all times except in the summer months. during autumn and winter infective larvae in pasture survived for periods of up to 32 weeks. little larval migration into soil was observed during this study and larvae did not survive for long in the faecal pellets during the summer. | 1987 | 3629723 |
| two field strains of haemonchus contortus resistant to rafoxanide. | two field strains of haemonchus contortus, one from pretoria on the highveld and the other from white river in the lowveld of the transvaal, showed pronounced resistance to rafoxanide at a dosage rate of 7.5 mg/kg live mass per os. both of these strains originated from kikuyu pastures under irrigation. resistance in south africa to rafoxanide and other anthelmintics, namely, closantel, ivermectin and the benzimidazoles is reviewed. it is concluded that apart from avoiding farming practices where ... | 1987 | 3306550 |
| the genetics of resistance and resilience to haemonchus contortus infection in young merino sheep. | 1987 | 3429127 | |
| lipid biosynthesis from 14c-glycerol in haemonchus contortus (nematoda: trichostrongylidae), in vitro. | 1987 | 3434509 | |
| further investigation of the primary mechanism of benzimidazole resistance in haemonchus contortus. | 1987 | 3440696 | |
| [ecoepidemiology of haemonchus contortus bahiensis, ecotype present in sheep of arid zones of venezuela]. | the frequency distribution of female haemonchus contortus bahiensis grisi, 1974 in sheep from venezuelan arid zones is 15.32% for the type with vulvar flap, 51.6% for the vulvar-knob and 33.07% for smooth type. a shannon-weaver diversity index corresponding to 1.44 bits was calculated for these forms with similarities in the general size, egg-size and in the number of the longitudinal cuticular ridges. an aggregated kind of distribution in the host population according to the k parameter of a ne ... | 1987 | 3507572 |
| [benzimidazole resistance in haemonchus contortus in a south german sheep herd]. | 1987 | 3297604 | |
| parasites as stressors: plasma cortisol responses of goats infected with the stomach worm haemonchus contortus to exogenous corticotropin (acth). | ten male, juvenile pigmy goats of similar age and weight were allocated randomly to two groups. goats in one group were each inoculated with 20,000 infective larvae of haemonchus contortus. the other group served as uninfected controls. goats were housed together, and precautions were taken to avoid the creation of differential, between group, stressogenic circumstances. body weights, nematode egg production, hematocrits, and clinical signs were monitored over a 61-day period following inoculati ... | 1987 | 3031870 |
| evaluation of an antigenic fraction of taenia hydatigena metacestode cyst fluid for immunodiagnosis of bovine cysticercosis. | an antigenic fraction (thfas) isolated from taenia hydatigena metacestode cyst fluid was used in an elisa to detect antibodies to t saginata in experimentally and naturally infected cattle. in 10 calves given 1,000 to 100,000 t saginata eggs (20% to 60% viability), igg and igm antibodies were detected in all the calves by post-inoculation week 3. immunoglobulin g antibody values remained increased until calves were slaughtered at post-inoculation weeks 13 to 26. six naturally infected calves (de ... | 1987 | 3631707 |
| protection of lambs with a purified metabolite of exsheathed third-stage haemonchus contortus larvae. | helminth-free lambs (approx 4 months old) were inoculated sc with a purified metabolite of exsheathed third-stage haemonchus contortus larvae. the metabolite was obtained from in vitro cultivation and was identified as xl3fa1. after 3 periodic xl3fa1 inoculations, lambs were challenge exposed with h contortus. multiple vaccinations with xl3fa1 did not inhibit the development of worm populations in the lambs; however, worm egg production seemed to be inhibited. | 1987 | 3631713 |
| 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 |
| 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 |
| 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 |
| interactions of benzimidazoles (bz) with tubulin from bz-sensitive and bz-resistant isolates of haemonchus contortus. | the binding of tritiated benzimidazoles (bzs)-albendazole, parbendazole, oxibendazole, mebendazole, oxfendazole and fenbendazole-to crude tubulin extracts from bz-susceptible and -resistant haemonchus contortus has been examined. for all bzs, the binding was substantially lower in the resistant isolate. the extent of this reduction was dependent on the structure of the bz, with mebendazole demonstrating superior binding to the resistant isolate than the other bzs. enrichment of the crude tubulin ... | 1986 | 3755220 |
| efficacy of repeated doses of levamisole, morantel, fenbendazole, and ivermectin against gastrointestinal nematodes in ewes. | levamisole, morantel, fenbendazole, or ivermectin was administered at 2-week intervals from may 1 through sept 14, 1985, to breeding ewes (20 ewes/drug) infected with various gastrointestinal nematodes. all ewes had fewer gastrointestinal nematode eggs per gram of feces (epg) after 2 treatments, compared with pretreatment epg counts. ewes administered ivermectin continued to have a low mean epg (0 to 3) throughout the study. the mean epg counts of ewes treated with levamisole increased from 3 to ... | 1986 | 3755877 |
| activity of ivermectin against natural infections by abomasal nematodes in lambs in controlled tests: evaluation of equine and bovine injectable formulations administered intraorally. | the efficacy of 2 injectable formulations of ivermectin, administered intraorally at the dosage of 200 micrograms/kg of body weight, was evaluated against naturally occurring infections by abomasal nematodes in lambs in 2 controlled tests. one test (a) included 17 lambs treated with the equine formulation and 16 nontreated lambs. for the other test (b), 14 lambs were treated with the bovine formulation, and 12 were nontreated. in controlled test a, only mature nematodes were recovered, and remov ... | 1986 | 3755309 |
| effect of ph and temperature on lipase and phospholipase of adult haemonchus contortus (nematoda: trichostrongylidae). | 1986 | 3735000 | |
| [haemonchus contortus: inhibition of prostaglandin synthesis by the abomasal mucosa promotes the development of the parasite]. | 1986 | 3943589 | |
| pathologic changes in lambs with ostertagia circumcincta infections associated with decreased infectivity of haemonchus contortus. | two experiments were done to examine the severity and type of abomasal lesions induced by moderate infections of ostertagia circumcincta in young lambs and to examine the differences in pathologic changes in lambs with monospecific and combined infections of o circumcincta and haemonchus contortus. observations included descriptions of gross and microscopic changes in the abomasums, as well as quantitative analysis of the thickness of the mucosa, numbers of mucus-containing cells, and inflammato ... | 1986 | 3954209 |
| control of helminthosis in lambs by strategic treatment with closantel and broad-spectrum anthelmintics. | treatment of ewes with broad-spectrum anthelmintic in august (pre-lambing) and early november, and of lambs in early november and early february, was effective in controlling infections with trichostrongylus spp in lambs reared on contaminated pastures under set-stocked conditions. it was ineffective in controlling infections with haemonchus contortus; 82% of lambs had to be withdrawn from the experiment because of severe haemonchosis. treatment with closantel (7.5 mg/kg) at the same times was v ... | 1986 | 3954695 |
| resistance to benzimidazole of haemonchus contortus utkalensis in sheep on martinique. | 1986 | 3962103 | |
| control of trichostrongylid pasture infestation in spring by the periparturient anthelmintic treatment of housed ewes prior to or at the time of turn out. | ewes, housed in late november and lambing in late february and march, were divided into three groups of eight, six and eight animals, and received a single treatment with ivermectin (approximately 200 micrograms kg-1) in late february (group i), on 15 april (group ii), or on 1 may (group iii), respectively. the egg output of the ewes and, subsequently, of eight lambs (group iv) was measured at 2-weekly intervals by counting and identifying the larvae after culture. group i showed a small rise in ... | 1986 | 3962158 |
| haemonchus contortus: lipid biosynthesis from 14c-labelled palmitic acid and sodium bicarbonate. | 1986 | 3034005 | |
| incorporation of carbon from 14c-labelled precursors into major chemical fractions of haemonchus contortus in vitro. | 1986 | 3034006 | |
| the periparturient rise in fecal egg counts in three strains of florida native ewes and its value in predicting resistance of lambs to haemonchus contortus. | 1986 | 3528003 | |
| the comparative efficacy of oxfendazole administered as bolus and suspension to naturally infected sheep in greece. | in a flock of 20 ewes naturally infected with those parasites of sheep most common in greece, and kept indoors during the whole trial, oxfendazole at the dose rate of approximately 2.9 and 2.8 mg/kg body-weight was tested as a 4 g bolus containing 112 mg active ingredient and a 2.265% suspension. the evaluation of its efficacy was based on the necropsy findings which were also supported by faecal egg counts. no differences in efficacy were noticed between the two formulations of the drug. both b ... | 1986 | 3745877 |
| cultivation of haemonchus contortus (nematoda: trichostrongylidae) from infective larvae to the adult male and the egg-laying female. | the parasitic nematode haemonchus contortus was cultured in vitro to the adult male and the egg-laying female. gastric contents from 2 cannulated calves and 2 sheep as well as extracts of stomach mucosa from both hosts were added to a mixture of api-1 culture medium and fildes' reagent (a pepsin digest of defibrinated bovine blood) adjusted to ph 6.4 for the first week and ph 6.8 thereafter. the gas phase was 85% n2:5% o2:10% co2. best results were obtained when api-1 culture medium plus fildes' ... | 1986 | 3734999 |
| the effect of dietary protein on the pathophysiology of acute ovine haemonchosis. | an experiment was conducted to examine the effect of dietary protein on the pathophysiology of acute haemonchosis in finn dorset/dorset horn lambs. erythrokinetic and metabolic studies using 51cr-red cells, 59fe-transferrin and 125i-albumin and digestive efficiency and nitrogen balance measurements were conducted between 19 and 39 days after infection. identical radioisotopic and nutritional studies were conducted later on pair-fed control lambs. the results demonstrated that lambs on a low prot ... | 1986 | 3716174 |
| developmental arrest of haemonchus contortus in sheep treated with a corticosteroid. | 1986 | 3804575 | |
| the effect of triflumuron (sir8514) on the free-living stages of sheep nematodes. | studies both in vitro and in vivo showed that the insect growth regulator, triflumuron, exhibited potent larvacidal effects against the free-living stages of trichostrongylus colubriformis. effects were not as marked on the closely related nematodes, haemonchus contortus and ostertagia circumcincta. nevertheless, these findings suggest that growth regulators may be used to develop novel methods of nematode control, and thus offer alternatives or adjuncts to conventional anthelmintic therapy and ... | 1986 | 3739204 |
| effect of cool storage of faecal samples containing haemonchus contortus eggs on the results of an in vitro egg development assay to test anthelmintic resistance. | an in vitro egg development assay was used to test the resistance of eggs from a benzimidazole susceptible and a resistant strain of haemonchus contortus to four benzimidazoles. storage of eggs contained in faecal samples at 4 degrees c for four, 24 or 72 hours did not appear to impair the results from the in vitro egg development assay or alter the ld50. storage for one week, however, proved to be lethal for the eggs. the average ld50 values for thiabendazole, albendazole, mebendazole and cambe ... | 1986 | 3704322 |
| haemonchus contortus and other trichostrongylid infections in parturient, lactating and dry ewes. | from autumn (april) to spring (november), groups of pregnant and dry merino ewes grazed pasture contaminated with infective larvae of haemonchus contortus, ostertagia circumcincta and trichostrongylus colubriformis. a periparturient rise in faecal egg counts occurred in the pregnant ewes, following the maturation in early spring of arrested fourth-stage larvae of h. contortus and failure of pregnant ewes to expel the resulting adult worms. peak egg counts were seen in september, just before lamb ... | 1986 | 3788026 |
| changes in serum pepsinogen and haemoglobin concentrations in calves infected with haemonchus contortus. | in four calves given haemonchus contortus larvae, the serum pepsinogen concentration rose quickly to reach a mean of 3.5 iu tyrosine on day 14 after infection. the mean concentration dropped to 1.8 iu tyrosine by day 23 and remained around 2.0 iu tyrosine until an anthelmintic was given on day 57, when concentrations returned to preinfection values. | 1986 | 3764097 |
| in vitro demonstration of in utero larval development in an oviparous parasitic nematode: haemonchus contortus. | the life-cycle of haemonchus contortus, a pathogenic stomach nematode of sheep, is typical of those of the other members of the superfamily trichostrongyloides, all of which require a period of development outside the definitive host. classically, gravid h. contortus, known as strictly oviparous, releases her eggs into the abomasal lumen. the eggs are passed out in the faeces in which they hatch into the 1st-stage larvae and then develop into the infective 3rd-stage larvae. we have developed a m ... | 1986 | 3785975 |
| [microecological characterization of parasitic nematoda present in goats of arid zones of venezuela]. | goats from the venezuelan northern arid zones were found infested by the following nematodes: haemonchus contortus, trichostrongylus axei, t. colubriformis, cooperia curticei, oesophagostomum columbianum, skrjabinema ovis y trichuris globulosa. the shannon-weaver index of diversity values oscillated between 0.045 and 1.73 bits (means = 1.16 +/- 0.24 bits). the maximum value of montly diversity ranged from 1 to 2.80 bits (means = 2.49 +/- 0.28 bits) and the equitability ranged from 0.045 to 0.67 ... | 1986 | 3587000 |
| effects of anthelmintics on haemonchus contortus (nematoda: trichostrongylidae). | the review summarizes and evaluates recent information about the effects of anthelmintics on haemonchus contortus. the topic is discussed under the headings effects of drugs on the absorptive surfaces, effects of drugs on metabolism, effects of drugs on the neuromuscular system, effects of drugs on developmental stages, anthelmintic efficacy, and resistant strains. possible future lines of work are suggested in the conclusions. | 1986 | 3511606 |
| the effect of dietary protein on the pathogenesis of acute ovine haemonchosis. | two experiments were conducted to examine the influence of dietary protein on parasite establishment and pathogenesis in finn dorset/dorset horn lambs infected with haemonchus contortus. the lambs were introduced to high (169 g) or low (88 g crude protein (cp) kg-1 dry matter (dm)) protein diets at 3 months of age and infected 1 month later with 350 larvae kg-1 body weight (bw). blood and faecal samples were collected for analysis and body weights recorded weekly. in the first experiment some of ... | 1986 | 3716173 |
| evaluation of three formulations of fenbendazole (10% suspension, 0.5% pellets, and 20% premix) against nematode infections in cattle. | anthelmintic efficacies of 3 formulations of fenbendazole were evaluated in cattle naturally parasitized with nematodes: a 10% oral suspension, 0.5% pellets as a top dressing on feed, and a 20% premix. all formulations of fenbendazole were greater than 99% effective in removing adults of haemonchus contortus, ostertagia spp, cooperia spp, and oesophagostomum radiatum. fenbendazole was greater than 96% effective in removing adults of strongyloides papillosus and greater than 85% effective in the ... | 1986 | 3516024 |
| the helminth parasites of various artiodactylids from some south african nature reserves. | the helminth species composition and helminth burdens of 4 grey duikers, 12 bushbuck, 2 nyala, 2 giraffe, a steenbok, an oribi, a waterbuck and a tsessebe from the kruger national park (knp); of a steenbok and a greater kudu from the farm riekerts laager, transvaal; of a single blue duiker from the tsitsikama forest national park, and of a blue wildebeest, a red hartebeest, a gemsbok and 2 springbok from the kalahari gemsbok national park (kgnp) were collected, counted and identified. new parasi ... | 1986 | 3725333 |
| transcuticular solute movement in parasitic nematodes: relationship between non-polar solute transport and partition coefficient. | the rate constants (k) for steroid transport across the isolated cuticle of ascaris suum were, linearly related to partition coefficients (p) of steroids in model solvents. the slope of log p vs log k for an isolated cuticle was closest to unity for the more polar solvents, octanol and ether, suggesting that the barrier to steroid movement across the cuticle has partition properties similar to these solvents. the transcuticular movement of steroids into intact adult a. suum and infective larvae ... | 1986 | 2874926 |
| haemonchus contortus: effect of ph and temperature on some dehydrogenases. | 1985 | 2940824 | |
| haemonchus contortus and ostertagia circumcincta: fenbendazole treatment and abomasal permeability changes in sheep. | effects of fenbendazole (7.5 mg/kg of body weight infused during 90 minutes) on abomasal transmural potential difference (pd), ph, and ionic concentrations were determined in 8 lambs fitted with permanent abomasal cannulae. four sheep were treated before inoculation and on day 28 after inoculation, with 200,000 3rd-stage ostertagia circumcincta larvae and 4 others were similarly inoculated with 15,000 3rd-stage haemonchus contortus larvae. in worm-free lambs, the unique effect was an increase in ... | 1985 | 3970427 |
| influence of dietary protein on the pathophysiology of ovine haemonchosis in finn dorset and scottish blackface lambs given a single moderate infection. | two experiments were conducted to examine the influence of dietary protein on the pathophysiology of haemonchus contortus in lambs of two breeds, namely finn dorset and scottish blackface. erythrokinetic and metabolic studies using 51cr-red cells, 59fe-transferrin and 125i-albumin, and digestive efficiency and nitrogen balance measurements were conducted between four and six weeks after infection. identical radioisotopic and nutritional studies were also conducted on pair-fed control lambs of bo ... | 1985 | 3975482 |
| influence of dietary protein on parasite establishment and pathogenesis in finn dorset and scottish blackface lambs given a single moderate infection of haemonchus contortus. | an experiment was conducted to examine the influence of dietary protein on parasite establishment and pathogenesis of haemonchus contortus in lambs of two breeds. finn dorset and scottish blackface. the lambs were introduced to high protein (170 g crude protein (cp) kg-1 dry matter (dm) or low protein (88 g cp kg-1 dm) diets at three months old and infected one month later with 125 larvae (kg bodyweight)-1. blood and faecal samples were collected for analysis and bodyweights recorded weekly. the ... | 1985 | 3975483 |
| resistance of exotic and domestic lambs to experimental infection with haemonchus contortus. | 1985 | 3980138 | |
| efficacy of ivermectin against induced gastrointestinal nematode infections in goats. | the efficacy of ivermectin (0.08 per cent w/v oral solution) at different dose levels was evaluated against induced infections of adult haemonchus contortus (21 days old) and trichostrongylus colubriformis (21 days old) and fourth stage larvae of oesophagostomum columbianum (17 days old), ostertagia circumcincta (five days old) and strongyloides papillosus (five days old). twenty-five boergoats (mutton goats) were randomly allocated by bodyweight within each sex to an untreated control group and ... | 1985 | 3840299 |
| anthelmintic activity of ivermectin against immature gastrointestinal nematodes of sheep. | twenty-four lambs of mixed breeding with mixed experimental infections of haemonchus contortus, ostertagia circumcincta, trichostrongylus axei, and t colubriformis were allotted to 4 groups. one group (control) was given the vehicle propylene glycol, and the others were given 100, 200, or 300 micrograms of ivermectin/kg of body weight by mouth. twelve days after treatment, the sheep were necropsied. the compound was greater than 99% effective against immature stages of 4 nematode species at all ... | 1985 | 3840965 |
| potentiation of the anthelmintic activity of oxfendazole by parbendazole. | the ability of parbendazole (pbz) to potentiate co-administered oxfendazole (ofz) was investigated. administration of a range (1.35-36.0 mg/kg) of doses of pbz with 4.53 mg ofz/kg demonstrated that significant potentiation occurred at 4.5 mg pbz/kg. at 4.5 mg pbz/kg, the area under the plasma ofz concentration curve was about twice that obtained from oral administration of ofz alone. when tested against benzimidazole-resistant haemonchus contortus and trichostrongylus colubriformis, the mixture ... | 1985 | 3840535 |
| [haemonchus contortus and ostertagia circumcincta: expulsion of parasites and restoration of the integrity of the abomasal mucosa after intraabomasal administration of arachidonic acid to the experimentally infested sheep]. | 1985 | 3935475 | |
| cuticular carbohydrates of three nematode species and chemoreception by trichostrongylus colubriformis. | the cuticle of haemonchus contortus, nippostrongylus brasiliensis and trichostrongylus colubriformis contained n-acetylgalactosamine and n-acetylglucosamine, based on the binding of fluorescein-labelled lectins. binding of the lectins varied between the sexes and body regions of the nematodes. treatment of male t. colubriformis with the lectin lens culinaris agglutinin (lca) reduced the feeding by helminths that was stimulated by histamine and the male's response to their female's pheromone, bas ... | 1985 | 3998961 |
| study of gastro-intestinal strongylosis in a sheep flock on permanent pasture 2. sheep parasitism in 1978-1979. | the epidemiological study carried out in 1977 in the limousin region of france was continued for the next two years. eighty-five lambs were slaughtered at the rate of five animals every weeks: sixty were slaughtered from may 1978 to march 1979 and twenty-five from may to september 1979. total parasite counts and coprological examinations were carried out. in spring the infestation of the lambs was early and heavy, and revealed that certain free-living stages can survive in low temperatures. the ... | 1985 | 4014986 |
| effects of season and physical condition on the gastrointestinal helminth community of white-tailed deer from the texas edwards plateau. | eighty-six adult female white-tailed deer, odocoileus virginianus (zimmermann), collected over a 12-mo period in the texas edwards plateau, harbored six species of nematodes (haemonchus contortus, gongylonema pulchrum, oesophagostomum venulosum, ostertagia ostertagi, cooperia sp., and apteragia odocoilei), and two cestodes (moniezia sp. and taenia hydatigena). the patterns of distribution of the three common species of gastrointestinal helminths (h. contortus, o. venulosum, and g. pulchrum) were ... | 1985 | 4032624 |
| haemonchus contortus: qualitative and quantitative analysis of lipids. | 1985 | 4050203 | |
| anthelmintic resistance in nematode parasites of goats. | cases of anthelmintic resistance on 3 goat farms in gippsland were investigated. on the first farm haemonchus contortus, trichostrongylus colubriformis and ostertagia (teladorsagia) circumcincta were found to be resistant to fenbendazole, but the first 2 species were fully susceptible to levamisole. on the second farm a population of t. colubriformis, resistant to concurrent full doses of levamisole and a benzimidazole, was found to retain this resistance when transferred to sheep. on the third ... | 1985 | 4051913 |
| enhancement of resistance of lambs to haemonchus contortus by previous infection with ostertagia circumcincta. | two experiments were performed to determine whether previous infection of young lambs with ostertagia circumcincta increased their resistance to the development of haemonchus contortus and to explore alterations in the microenvironment of the abomasum related to the interaction. the parasitic infections were monitored with periodic fecal egg counts and by recovery and enumeration of parasites at necropsy of the lambs. alteration of the microenvironment was examined by measurement of serum gastri ... | 1985 | 4062019 |
| the contribution of a partial tricarboxylic acid cycle to volatile end-products in thiabendazole-resistant and susceptible trichostrongylus colubriformis. | acetate, propionate, ethanol and propanol were the predominant end-products released during incubation of a thiabendazole resistant and a susceptible strain of trichostrongylus colubriformis. the parasites in all the incubations appeared to be deficient in reducing equivalents if the end-products arose from the classical catabolic pathway through fumarate reductase (ec 1.3.1.6). possible alternative pathways for accounting for redox balance, including beta-oxidation, the pentose phosphate pathwa ... | 1985 | 3990706 |
| the seasonal prevalence of inhibited development of haemonchus contortus in sheep in senegal. | throughout a period of 13 months, the abomasa of 1024 sheep, living in a sahelian region, were examined for adult haemonchus contortus and their inhibited l4 larvae. of these 796 (78%) were found harbouring h. contortus, but with low worm burdens (geometric mean 37). significant numbers of inhibited larvae appeared early in the dry season (november) and they represented 49% of the total in december. a similar proportion of inhibited larvae were present until april and after that their number dec ... | 1985 | 3992869 |
| regulation of haemonchus contortus populations in sheep exposed to continuous infection. | 1985 | 4066146 | |
| studies on the abomasal pathology of immunized and non-immunized sheep infected with haemonchus contortus. | five adult ewes and five lambs were repeatedly immunized with weekly doses of 10,000 irradiated haemonchus contortus l3 before challenge with 100,000 and 10,000 normal larvae respectively. two groups of non-immunized ewes and lambs were similarly challenged and one animal from each of the four groups killed on days 3, 5, 7, 10 and 24 post-challenge. the cellular changes in the abomasal mucosa were less marked in the non-immunized groups than in the immunized animals and appeared later in the lam ... | 1985 | 4093592 |
| 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 helminths of various antelope species from natal. | helminth parasites were collected from 2 bushbuck, tragelaphus scriptus, 2 red duiker, cephalophus natalensis, 1 oribi, ourebia ourebi, and 4 reedbuck, redunca arundinum, that died or were culled in various parts of natal. one trematode genus, 1 cestode genus and 12 nematode species were recovered. haemonchus contortus. ostertagia harrisi, trichostrongylus capricola, trichostrongylus vitrinus, cooperia rotundispiculum and setaria scalprum are new parasite records for the red duiker. trichostrong ... | 1984 | 6241958 |
| effect of ph and temperature on four dehydrogenase enzymes of haemonchus contortus. | 1984 | 6242277 | |
| partial biochemical and serological characterization of exsheathing fluid and somatic extracts of infective larvae and adult females of haemonchus contortus. | exsheathing fluid from infective larvae of haemonchus contortus may contain antigens which induce protective immunity upon infection in sheep. in this study, a rapid method of preparing exsheathing fluid was used to determine its biological activity, purity and antigenic complexity. protein in exsheathing fluid ranged from 21-59.5 micrograms/ml and no carbohydrate was detected. gel filtration showed a single broad peak which retained biological activity and polyacrylamide gel electrophoresis dem ... | 1984 | 6426763 |
| energy metabolism of adult haemonchus contortus in vitro: a comparison of benzimidazole-susceptible and -resistant strains. | in vitro biochemical characteristics of three strains of haemonchus contortus, benzimidazole-susceptible, mebendazole-resistant and thiabendazole-resistant isolates, were investigated. steady-state pool sizes of glucose and metabolic intermediates, including adenine nucleotides and end-products revealed no differences between adult worms resistant or susceptible to benzimidazoles in 30-60 min incubations. possible regulatory steps in the glycolytic pathway are identified as those involving the e ... | 1984 | 6427605 |
| effect of cimetidine on abomasal ph and haemonchus and ostertagia species in sheep. | cimetidine, a histamine h2-receptor blocking agent which reduces gastric acid flow in simple stomach animals was administered directly into the abomasum of sheep at 100 mg kg-1 twice daily for five consecutive days and again on the eighth day. the drug caused a significant increase in the ph values of the abomasal contents and was highly effective in reducing the adult population of haemonchus contortus (100 per cent) and ostertagia circumcincta (70 per cent) in the abomasum of sheep. the possib ... | 1984 | 6463375 |
| studies on haemonchus contortus. ix. the effect of trichostrongylus axei in merinos on natural pasture. | four groups of 6-7-month-old merino lambs were each dosed with 40 000 infective larvae of trichostrongylus axei on 2 november 1976 and subsequently exposed to challenge with haemonchus contortus on natural grazing at the university of pretoria's experimental farm in the eastern suburbs of pretoria. one of these groups and one group of controls were killed every 8 weeks from the end of december 1976-june 1977. predosing with t. axei was greater than 50% effective against 5th stage and adult h. co ... | 1984 | 6462631 |
| studies on haemonchus contortus. x. the effect of trichostrongylus axei in merinos on artificial pastures. | a recently established eragrostis curvula pasture 1,1 ha in size at hennops river in the transvaal highveld was contaminated from 6 october 1976 until 20 may 1977 by 30 weaned merinos, each infested with 7 000 infective larvae of h. contortus. on 2 november 1976 3 groups of weaned merinos and again on 10 january 1977 a further group of merinos were infested with 40 000 infective larvae of trichostrongylus axei. from 19 november a single group of sheep, predosed with t. axei, and a control group ... | 1984 | 6462632 |
| prevalence of anthelmintic resistant nematodes in sheep in south-east england. | the prevalence of anthelmintic resistant nematodes among 52 commercial flocks in south-east england was investigated by comparing the faecal egg counts of groups of lambs before, and seven days after, treatment with thiabendazole and levamisole. evidence of thiabendazole resistance was found on seven farms. in each case haemonchus contortus was the only species of nematode involved. in vitro egg hatch assays carried out for isolates from these farms gave ed50 estimates of 0.065 to 0.332 microgra ... | 1984 | 6464318 |
| the effect of anaerobiosis on adenosine triphosphate levels in larval nippostrongylus brasiliensis and haemonchus contortus. | the adenosine triphosphate (atp) content of the pre-parasitic stages of nippostrongylus brasiliensis, haemonchus contortus (l1, l2 and l3) and the adults of the free-living nematode, panagrellus redivivus, have been measured by bioluminescent photometry in aerated or near-anoxic conditions. the atp content of the l1 and l2 stages of both parasitic species was unaltered by a lack of oxygen over a 90-min period. however, the l3 stage of both species and the adults of p. redivivus showed a signific ... | 1984 | 6506845 |
| studies on the pathophysiology of chronic ovine haemonchosis in merino and scottish blackface lambs. | an experiment was conducted to examine, under laboratory conditions, the pathophysiology of chronic ovine haemonchosis. in the present study, groups of merino and scottish blackface lambs were maintained on a low plane of nutrition and infected with 50 haemonchus contortus larvae/kg live weight. the parasitized lambs along with respective breed controls were examined over a 27-week period. in addition to the body weight, haematological and parasitological parameters, erythrokinetic, metabolic, d ... | 1984 | 6514383 |
| the effect of transfer factor treatment on two challenge infections of haemonchus contortus in immuno-competent 7-month-old lambs. | a number of immuno-competent blackface lambs were infected with 10,000 haemonchus contortus third stage larvae and were later challenged with a second dose of 10,000 h. contortus third stage larvae. one group of lambs was treated with dialysed transfer factor prior to the second challenge dose. histological changes in the abomasal wall, reductions in abomasal worm burdens at slaughter and faecal egg counts monitored throughout the experiment suggested the presence in some animals of an innate re ... | 1984 | 6516210 |
| stocking rate effects on the worm burdens of angora goats and merino sheep. | worm egg counts of yearling angora or merino wethers grazing in mixed flocks at either 4/ha or 8/ha were observed over a 5 month period. based on faecal egg counts infection levels in the sheep increased for the first 3 months and then decreased as the animals developed resistance. egg counts in the goats did not decrease during the experiment. post mortem worm counts indicated that there was a significant host species--stocking rate interaction on worm burdens of haemonchus contortus adults and ... | 1984 | 6517775 |
| the structure of excretory system of the infective larva of haemonchus contortus. | 1984 | 6526575 | |
| effects of bovine heme on development of haemonchus contortus in vitro. | 1984 | 6527196 | |
| wool production of sheep chronically infected with haemonchus contortus. | a chronic infection was established in a group of twenty 18-month-old non-reproductive merino ewes by oral administration of 3000 infective h. contortus larvae twice weekly for 12 weeks. their live-weights and wool production were compared with those of 20 uninfected ewes grazing the same pasture. in the infected sheep, faecal egg counts increased over a period of 9 weeks to reach a mean of 5000 eggs per gram, accompanied by small, but significant effects on packed-cell volume and live-weight. t ... | 1984 | 6541834 |
| studies on haemonchus contortus. xi. the effect of a bovine strain of trichostrongylus axei in merinos on natural pastures heavily infested with h. contortus. | sheep grazed on natural pastures heavily infested with infective larvae of haemonchus contortus. sixty-eight weaned merinos were divided into 6 groups on day 0 (23 november 1977), and on day +14 (7 december) 79 merinos were divided into 7 groups. there were 2 groups of undosed controls and other groups were either dosed with infective larvae of trichostrongylus axei (bovine strain) only on days 0 and +14, or in combination with h. contortus, or with subsequent doses of h. contortus, 28 days late ... | 1984 | 6462634 |
| studies on haemonchus contortus. xii. effect of trichostrongylus axei in dorper lambs on natural pasture lightly infested with h. contortus. | weaned dorper lambs on natural pasture were predosed with 40 000 infective larvae (l3) of trichostrongylus axei, irradiated (0,3 kgy) l3 of t. axei or closantel at 10 mg/kg either in september or november 1978 and were compared with merino yearlings predosed with 40 000 l3 of t. axei in november 1977. the following summer (december-march) only 178,6 mm of rain fell and very few h. contortus were present on pastures. artificial challenge with 20 000 l3 of haemonchus contortus with the local strai ... | 1984 | 6462635 |
| [kinetics of the population of worms in various developmental stages, haemonchus contortus in sheep after a single experimental infection] experimental infection]. | this work was performed to study, in 147 month-old male lambs experimentally infected with 14000 haemonchus contortus infective larvae and slaughtered at 6, 12, 18 and 24h and at 2, 6, 8, 11, 15 and 39 days post-infection (pi): 1, the importance, localisation and nature (with or without sheath) of the worms during the first 24 h pi; 2, the kinetics of the total worm population and of each evolutionary stages from the first to the 39th day pi: 3, the period of emergence of the fourth-stage larvae ... | 1984 | 6529116 |
| serum and abomasal antibody response of sheep to infections with haemonchus contortus. | serum and abomasal iga, igg and igm antibody response against adult worm, l3 and egg antigens of haemonchus contortus was monitored by the elisa technique after one or two infections with this nematode. following the first infection, antibody levels in serum did not change materially. after administration of a challenge dose of infective larvae, antibodies of the three immunoglobulin classes in infected animals rose slightly, but this rise appeared later than the fall in the faecal egg counts. i ... | 1984 | 6538719 |
| resistance to haemonchus contortus transferred between genetically histocompatible sheep by immune lymphocytes. | the pattern of faecal egg counts after infection with 10,000 haemonchus contortus larvae was similar within but not between, four pairs of monozygous twin sheep. transfer of whole lymph or washed lymph cells from three immune donor sheep to their identical co-twin recipients reduced the susceptibility of the recipients to challenge with 10,000 larvae as measured by faecal egg counts. cells from a nonimmune donor did not have this effect. in a final experiment, washed cells from an immune triplet ... | 1984 | 6542246 |
| some factors influencing the immunisation of sheep with irradiated haemonchus contortus larvae. | over the last 6 years a number of experiments in which sheep were successfully immunised with 2 doses of 10 000 haemonchus contortus larvae, irradiated at 60 krad in a gamma-source, have been reported by the authors. in this paper, the failure of such a regimen of immunisation, using the same strain of larvae, is reported together with an investigation of the possible causes. technical errors were eliminated as a cause, on the grounds that the failure occurred in 2 separate laboratories using di ... | 1984 | 6542728 |