细化搜索
结果 1-10 的 31
Occurrence of gastrointestinal parasites in camels in the Tianshan Mountains pastoral area in China
2020
Guowu, Zhang | Kai, Zhang | Xifeng, Wang | Chunhui, Ji | Chengcheng, Ning | Yue, Zhao | Jun, Qiao | Qingling, Meng | Xingxing, Zhang | Kuojun, Cai | Jinsheng, Zhang | Zaichao, Zhang | Xuepeng, Cai
Gastrointestinal parasites are some of the most common pathogens which are seriously harmful to the camel’s health. The infection status of gastrointestinal parasites in camels (Camelus bactrianus) in the Tianshan Mountains pastoral area in China is still unclear. The aim of this study was to investigate the species and infection intensity of gastrointestinal tract parasites in local camels. A total of 362 fresh faecal samples were collected and examined for parasite eggs using the saturated saline floating and natural sedimentation method. The parasite eggs were subjected to morphological and molecular examination and identification, and the infection rate and mean intensity of the parasites were analysed. A total of 15 gastrointestinal tract parasite species’ eggs were identified, with a detection rate of 100%. Ostertagia spp. (100%) and Trichostrongylus spp. (98.1%) were dominant. Camels were often coinfected by 5–14 species. The average number of eggs per gram of faeces was higher for Ostertagia spp. (298), Haemonchus contortus (176) and Nematodirus spp. (138). The number of species of parasites infecting young camels was significantly lower than that of adult camels, but the infection intensity in young camels was significantly higher. Gastrointestinal parasites were highly prevalent in camels from the Tianshan Mountains pastoral area in China. This finding provides important epidemiological data for the prevention and control of associated infections in camels.
显示更多 [+] 显示较少 [-]Multidrug resistance in Haemonchus contortus in sheep - can it be overcome?
2023
Babják Michal | Königová Alžbeta | Komáromyová Michaela | Kuzmina Tetiana | Nosal Pawel | Várady Marián
Gastrointestinal nematodes pose a threat to animal health and affect farmers by negatively impacting farm management.
显示更多 [+] 显示较少 [-]Controlled tests on activity of contemporary parasiticides on natural infections of helminths in lambs, with emphasis on strains of Haemonchus contortus isolated in 1955
1992
Lyons, E.T. | Drudge, J.H. | Tolliver, S.C. | Stamper, S.
Ten controlled tests were done between 1972 and 1989, in lambs on pasture, evaluating activity of fenbendazole (FBZ; 5 mg/kg of body weight), oxfendazole (OFZ; 3.5 and 10 mg/kg), oxibendazole (OBZ; 10 mg/kg), pyrantel pamoate (PRT; 25 mg of base/kg), and thiabendazole (TBZ; 44 and 50 mg/kg) against natural infections of helminths, with emphasis on 2 strains (A and B) of Haemonchus contortus. Strain A was phenothiazine-susceptible and strain B was phenothiazine-resistant when isolated in 1955. For approximately 10 years prior to these tests, sheep infected with both strains had been treated periodically each year with several compounds, including thiabendazole, which was used many more times than the other drugs. For this study, 4 (FBZ, OFZ, OBZ, and PRT) of the 5 compounds were evaluated in either 1 or 2 controlled tests. The fifth compound, TBZ, was used for 5 tests. Strain A H contortus was resistant to TBZ for all years tested, but more susceptible to FBZ, OFZ, OBZ, and PRT. Overall, strain B was susceptible to TBZ (with a few exceptions), and also to FBZ, OFZ, OBZ (activity less on immature forms), and PRT. Other abomasal parasites (2 species of Ostertagia and 3 of Trichostrongylus) were found in low numbers, but removal overall was good for the compounds tested. Trichostrongylus axei, found in higher numbers than species of Ostertagia and other species of Trichostrongylus, were effectively removed by all compounds in most cases. Activities of TBZ and PRT were also evaluated against several species of intestinal helminths, most of which were found in low numbers. Cooperia curticei were inconsistently removed by TBZ, but activity of PRT was effective. Both compounds were active on mature Nematodirus spathiger, but TBZ had variable activity on immature forms. Strongyloides papillosus were effectively removed by TBZ. Other parasites found in lower numbers than the aforementioned 3 species were Capillaria spp, Trichuris spp, and Oesophagostomum columbianum; removal was variable for both drugs.
显示更多 [+] 显示较少 [-]Evaluation of Haemonchus contortus infections in sexually intact and ovariectomized ewes
1988
Fleming, M.W. | Rhodes, R.C. III. | Gamble, H.R.
Three experiments were conducted to investigate experimentally the occurrence of periparturient nematode egg rise in ewes and the hormonal modulation of Haemonchus contortus infections. In the first experiment, fall-bred and winter-bred pregnant (n = 4 and 14, respectively) and nonpregnant (n = 5 and 29, respectively) ewes were treated with anthelmintic and were pastured together on fields that were contaminated with H contortus. Three weeks before lambing, all ewes were placed in concrete pens; fecal egg counts for the winter-bred group were obtained on alternate days. Pregnant and lactating ewes had significantly larger numbers (P < 0.01) of H contortus eggs than did the nonpregnant controls 1 week before and after lambing. Lactating, fall-bred ewes had significantly (P < 0.01) more adult worms in their abomasum through natural acquisition than the nonpregnant controls. In the second experiment, fall-bred and winter-bred helminth-free, pregnant (n = 4 and 8, respectively) and nonpregnant (n = 3 and 15, respectively) ewes were inoculated on 5 alternate days, beginning 70 days after breeding with 20,000 infective H contortus larvae. The ewes were maintained on concrete pens throughout pregnancy. Fecal egg counts were significantly (P < 0.05) greater in pregnant ewes, beginning 1 week before lambing until 1 week after lambing. Abomasums of lactating ewes from both lambing seasons yielded significantly (P < 0.01) more adult worms at necropsy than nonpregnant ewes. In the third experiment, ewes were ovariectomized (n = 15) or sham-operated (n = 9); half of the control ewes were bred. Beginning on day 70 of pregnancy, all ewes were inoculated orally with 20,000 infective H contortus larvae on 5 alternative days. Abomasums were removed from all ewes after lambing, and adult worms were recovered. Pregnant ewes and half of the ovariectomized ewes had significantly (P < 0.05) more worms than did the sham-operated ewes.
显示更多 [+] 显示较少 [-]Haemonchus contortus from the vaal ribbok, Pelea capreolus, and the bontebok, Damaliscus dorcas dorcas, in the Bontebok National Park
1983
Boomker, J. | Horak, I.G. | Gibbons, L.M. | De Vos, V.
Haemonchus contortus with exceptionally long spicules recovered from vaal ribbok and bontebok, measurements
显示更多 [+] 显示较少 [-]Anthelmintic efficacy of ivermectin against gastrointestinal nematodes in calves
1983
Benz, G.W. | Ernst, J.V. | Crawley, R.R.
gastrointestinal nematodes, calves (exper.), efficacy of ivermectin given subcutaneously or given orally as drench or paste
显示更多 [+] 显示较少 [-]Efficacy of ivermectin against naturally acquired and experimentally induced nematode infections in sheep
1982
Wescott, R.B. | LeaMaster, B.R.
The activity of ivermectin against common nematode parasites of sheep was examined in 2 experiments. In the 1st experiment, 14 sheep with naturally acquired infections were assigned to 2 groups of 7 sheep each. Sheep in 1 group were treated with 200 micrograms of ivermectin/kg of body weight and the remainder served as nontreated controls. In the 2nd experiment, 15 sheep with experimentally supplemented infections (including a benzimidazole-resistant strain of Haemonchus contortus) were assigned to 3 groups of 5 each. The 1st group was treated with 200 micrograms of ivermectin/kg, the 2nd was treated with 88 mg of thiabendazole/kg, and the 3rd served as nontreated controls. Ten to 12 days after treatment, all sheep were euthanatized and necropsied, and the parasites they harbored were recovered and identified. Efficacy of ivermectin was excellent (greater than 96%) against Dictyocaulus filaria, H contortus, Ostertagia circumcinta, Marshallagia marshalli, Trichostrongylus axei, T colubriformis, and T vitrinus. Treatment was not as uniformly effective for Nematodirus spathiger (73% to 85%), N filicollis (80% to 96%), Cooperia curticei (92% to 100%), immature nematodes (92% to 100%), and early 4th-stage larvae (46% to 100%). Efficacy of thiabendazole was poor for H contortus (42%) and early 4th-stage larvae in the abomasum (52%), but approached 100% for most of the other parasites.
显示更多 [+] 显示较少 [-]Study on DNase activity specific from Haemonchus contortus reproductive tissue
Kwak, D.M.(Washington State University, Pullman, WA, USA)E-mail:dmkwak@vetmed.wsu.edu
DNase activity in Haemonchus contortus reproductive tissue was characterized and compared to that in whole worm. DNase activity in reproductive tissue was detected throughout pHs 4-10 with high activity under acidic conditions. The activity was not inhibited by 10 mM EDTA at pH 5.0, but largely inhibited by pH 7.0. The activity produced DNA fragments with mixtures of 3'-hydroxyls (OH) and 3'-phosphates (P) at each pH. Three distinct DNase activities were identified and had M∧rs of 34, 36 and 38.5 kDa in zymograms, which were distinguished according to pH requirement and sensitivity to EDTA.
显示更多 [+] 显示较少 [-]In vitro anti-parasitic activities of pomegranate, Punica granatum against parasitic nematodes of ruminants
2018
Siti Futri Farahininajua Fikri | Nik Ahmad Irwan Izza Suhaila Ab. Hamid | Rahmad Zakaria | Shaida Fariz
Parasitic nematode infection in animal is one of the main causes for the mortality of animals and most of the treatment relies on the use of the anthelmintic drugs to overcome such a problem. However, the heavy use of anthelmintic contributed to the problem of multidrug resistance. This study was carried out to investigate the infectiveness of Punica granatum (aqueous leaf and peel extracts) as an alternative treatment. This study utilised the in-vitro assay technique (motility assayand larval migration inhibition assay) to determine the effect of the extracts on the survival of L3 stage of parasitic nematodes.The results showed that incubation of L3 in different concentrations (5, 10, 20, 50 and 100 mg/ml) of extracts paralysed and killed the worms after 24 hours and 48 hours ofincubation periods. The same results were obtained from larval migration inhibition assay, showing that both extracts of Punicagranatum inhibited the migration of the L3. After 2 hours of incubation in the leaf extract (5 mg/ml), the migration of nematode larvae was inhibited to 56±12.29% as compared tothe control. While for the peel extract the percentage of migration was reduced to 53 ±3.33%. Further reduction of the migration was observed at 10, 20 and 50 mg/ml of leaf extract.
显示更多 [+] 显示较少 [-]Relative economic benefits of tactical anthelmintic treatment and urea-molasses block supplementation of Boer goats raised under extensive grazing conditions at Onderstepoort, Pretoria, South Africa
2008
Vatta, A.F.(Onderstepoort Veterinary Institute ,University of KwaZulu-Natal) | Krecek, R.C.(University of Johannesburg) | Pearson, R.A.(University of Edinburgh Royal (Dick) School of Veterinary Studies Division of Veterinary Clinical Science (incorporating Centre for Tropical Veterinary Medicine)) | Smith, M.F.(Agricultural Research Council) | Stenson, M.O.(Onderstepoort Veterinary Institute) | Van Wijk, E.F.(Onderstepoort Veterinary Institute) | Harrison, L.J.S.(University of Edinburgh Royal (Dick) School of Veterinary Studies Division of Veterinary Clinical Science (incorporating Centre for Tropical Veterinary Medicine))
The potential economic benefits of combining tactical anthelmintic treatment for gastrointestinal nematodes and nutritional supplementation with urea-molasses blocks were examined in Boer goats raised under extensive grazing conditions in the summer rainfall area of South Africa. Eight groups of nine goats were monitored over a 12-month period from 1 October 2002 to 9 October 2003. Ad libitum nutritional supplementation with urea-molasses blocks was provided when the goats were housed at night, during the summer (wet season-December 2002 to February 2003), and/or the winter (dry season-June 2003 to August 2003). All the goats were treated symptomatically for Haemonchus contortus infection when deemed necessary by clinical examination of the conjunctiva for anaemia using the FAMACHA© system. Half the groups were tactically treated for gastrointestinal nematodes in mid-summer (28 January 2003). Under the symptomatic treatment, climatic and extensive grazing conditions encountered during the trial, feed supplementation in the winter dry season had the greatest economic benefit and is therefore recommended. Tactical anthelmintic treatment afforded no additional advantage, but the nematode challenge was low.
显示更多 [+] 显示较少 [-]