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1.
Calves experimentally infected with Haemonchus, Ostertagia, and Cooperia, and to lesser degrees with Trichostrongylus, Oesophagostomum, Nematodirus, and Bunostomum were used in a controlled experiment to record the anthelmintic efficacy of a benzimidazole compound methyl 5-(phenylthio)-2-benzimidazolecarbamate at dosage levels of 3.5, 5, and 7.5 mg/kg bodyweight. With the 3 dosages, reductions of Haemonchus were 96.7, 99.2, and 99.8%; of Ostertagia, 97.2, 97.2, and 99.5%; and of Cooperia, 99.9, 99.9, and 99.9%. Pronounced reductions were also recorded for Trichostrongylus, Nematodirus, Oesophagostomum, Trichuris, and Capillaria, but these populations were too numerically small or too unevenly distributed within the control groups to be given much emphasis. The experimental parasitic populations which developed in the 10 control calves amounted to 91, 763 worms (total). 相似文献
2.
Agneessens J Claerebout E Dorny P Borgsteede FH Vercruysse J 《Veterinary parasitology》2000,90(1-2):83-92
Over a period of 1 year, from November 1997 to October 1998, the abomasa, blood and faecal samples of 121 dairy cows in Belgium were collected and examined for nematode infections. Nematodes were present in the abomasa of 110 animals. Ostertagia was found in all 110, Trichostrongylus was seen in 65 and Haemonchus in 14 abomasa. Overall, 91% of all trichostrongyles recovered were Ostertagia. The geometric mean total number of Ostertagia was 2750, with an average of 74% inhibited early fourth stage larvae (EL4). Between November and February >90% of the Ostertagia worm burden were EL4 stages. The majority of the animals (56%) harboured a low Ostertagia burden (100-5000) and 15% had a high burden (>10,000). Sixty-four percent of the coprocultures were positive and the genera recovered were Ostertagia sp. (100%), Trichostrongylus sp. (42%), Oesophagostomum (32%), Haemonchus sp. (29%) and Cooperia sp. (16%). A seasonal pattern was evident for serum Ostertagia-specific antibodies and for serum pepsinogen concentration, with the highest levels during the summer, and low values during the winter. Dictyocaulus viviparus specific antibodies were detected in the serum of eight (7%) animals. 相似文献
3.
Sheep and alpacas of similar age groups (6, 18 and 36+ months) were grazed for 16 weeks on pasture contaminated by lambs. Faecal egg counts, bulked larval cultures, lungworm larvae in faeces, dag scores, liveweight changes and nematode larvae on pasture were measured. Chabertia, Oesophagostomum, Cooperia, Ostertagia and Haemonchus and Trichostrongylus larvae were cultured from both the sheep and the alpacas. For the respective age groups, the alpacas had lower liveweight gains (10, 32 and 47 g/d vs 88, 84 and 120 g/d), peak faecal egg counts (384, 50 and 60 epg vs 1500, 500 and 140 epg) and faecal contamination of the perineum than the same ages of sheep. These results suggest alpacas became less affected with gastrointestinal nematodes than sheep. 相似文献
4.
McKenna PB 《New Zealand veterinary journal》1995,43(6):225-227
Larval cultures and faecal egg count reductions were used to determine the identities and frequencies of occurrence of nematode genera involved in cases of ovine anthelmintic resistance submitted to the Batchelar Animal Health Laboratory between 1992 and 1994. Based on an examination of 102 cases, it was found that, while there were some differences relating to the method of assessment, the genera most frequently involved were Trichostrongylus, Ostertagia and Nematodirus. Also implicated, although less commonly, were infections of Oesophagostomum/Chabertia, Haemonchus and Cooperia. The majority of cases involved resistance in two or more genera, with resistance in a single nematode genus occurring in 45% of cases. Most such monogeneric resistances comprised infections of Trichostrongylus (52%), Ostertagia (17%) or Nematodirus (11%). Anthelmintic resistance involving Haemonchus alone was found in only three cases. These results suggest that the potential role of narrow-spectrum drenches in the management and control of anthelmintic-resistant worms in New Zealand sheep is likely to be strictly limited. 相似文献
5.
Borgsteede FH Tibben J Cornelissen JB Agneessens J Gaasenbeek CP 《Veterinary parasitology》2000,89(4):287-296
Abomasa, blood samples and faecal samples for examination of nematode infections were collected from 125 dairy cows during the period November 1997-October 1998. Of these, 12 had no grazing history and were, therefore, excluded from this study. From the remaining 113, 88.5% had nematode eggs in the faeces. Larval identification of the positive cultures showed that Ostertagia spp. larvae were most frequent (97%), followed by Trichostrongylus spp. (29%), Oesophagostomum spp. (23%), Cooperia punctata (20%), Cooperia oncophora (4%), Haemonchus contortus (2%) and Bunostomum phlebotomum (1%). The geometric mean EPG was 2.4. Two cows excreted larvae of Dictyocaulus viviparus (0.1 and 0.6 LPG resp.). Worms were found in the abomasa of 108 cows (96%). In all these abomasa Ostertagia spp. was present (100%). Trichostrongylus axei was found in 47 abomasa (43.5%) and two cows (2%) were infected with Capillaria bovis. The geometric mean of the total abomasal worm counts was 1743 and of Ostertagia spp. alone 1615. Almost all male worms were Ostertagia ostertagi, only occasionally Skrjabinagia lyrata10,000) total worm burden.Ostertagia specific antibodies were highest in late summer and autumn and lowest in spring and early summer. The same pattern, although not so pronounced, was observed for the serum pepsinogen values. No clear seasonal pattern was found for the Cooperia specific antibodies. Antibodies against D. viviparus were detected in seven cows (6%). 相似文献
6.
O Helle 《Acta veterinaria Scandinavica》1971,12(4):504-512
Using 21 worm-free lambs in paddocks on old sheep pastures on 4 farms near Oslo, it was found that Nematodirus spp., Ostertagia spp. and Moniezia spp. were the only helminths which could survive the winter in the pasture in great numbers. A few Teladorsagia davtiani, Chabertia ovina, Trichuris ovis, Cooperia onchophora and Skrjabinema ovis survived the winter. Trichostrongylus axei, T. vitrinus and Oesophagostomum venulosnm showed a negligible ability to survive the winter in the pasture. The following species were never found to survive: Haemonchus contortus, Trichostrongylus colubriformis, Bunostomum trigonocephalum, Cooperia curticei and Strongyloides papillosus. 相似文献
7.
Infective larvae of selected batched of the following nematode species from sheep and cattle were examined for survival and infectivity (by injection into either the abomasum, the duodenum, or the jugular vein) after having been stored in liquid nitrogen for 103-136 months: Haemonchus contortus, Haemonchus placei, Ostertagia circumcincta, Ostertagia ostertagi, Marshallagia marshalli, Cooperia spp., Trichostrongylus axei, Trichostrongylus colubriformis, Trichostrongylus falculatus, Nematodirus spathiger, Nematodirus helvetianus, Oesophagostomum columbianum, Oesophagostomum radiatum, Chabertia ovina and Dictyocaulus filaria. Excluding D. filaria, a mean of 97.7% of the ovine and 96.0% of the bovine nematode larvae were alive when thawed. Compared with previous investigations in this series, little or no reduction occurred with time in either the survival or the viability of the nematodes from cattle, or in the survival of those from sheep. In contrast, the larvae developed poorly in sheep, possibly owing to parenteral treatment of the animals with ivermectin at a dosage of 0.4 mg kg-1, either 6 or 8 days before they were infected. 相似文献
8.
J D Kelly H V Whitlock R S Hogarth-Scott F A Mears 《Research in veterinary science》1975,19(1):105-107
Fenbendazole (methyl-5-(phenylthio)-2-benzimidazole carbamate) at dose rates of 5 mg/kg and above was 100 per cent effective in eliminating a naturally acquired Dictyocaulus filaria infection in sheep. The drug was 100 per cent effective in eliminating concurrent infections of adult Trichostrongylus axei, Haemonchus contortus, Haemonchus placei, Ostertagia circumcincta, Ostertagia ostertagii, Cooperia oncophora, Cooperia mcmasterii, Nematodirus spathiger, Neumatodirus filcollis, Oesophagostomum venulosum and Chabertia ovina. Fenbendazole was 93 per cent and 97 per cent effective at doses of 5 and 10 mg/kg respectively in removing infection with adult T colubriformis, and post-treatment worm-egg production was completely suppressed in surviving female worms. No adverse side-effects were observed in treated sheep at either of the two dose rates used. 相似文献
9.
The benzimidazole anthelmintic, oxfendazole, was used as an oral suspension at 4.5 and 2.8 mg/kg to treat naturally infested indigenous buffaloes in Egypt. Worms of the genera Haemonchus, Cooperia, Trichostrongylus, Ostertagia, Chabertia and Oesophagostomum were identified in the animals prior to treatment. A 100% reduction in faecal egg counts was obtained at the 4.5 mg/kg level when compared to untreated control animals. Reductions in faecal egg counts greater than 90% were recorded at 2.8 mg/kg and these exceeded reductions obtained by drenching with the older benzimidazole anthelmintic, thiabendazole, at 67 and 111 mg/kg. 相似文献
10.
Critical anthelmintic tests and controlled trials were used to assess the efficiency of laevo -tetramisole hydrochloride against nematode infections in sheep and cattle.
In sheep, oral dose rates of 5 mg/kg and above were 94 to 100% effective against adult Haemonchus contortus , intestinal Trichostrongylus spp, Nematodirus spp, Oesophagostomum columbianum, O. venulosum and Chabertia ovina . A dose rate of 7.5 mg/kg was required for consistently high activity against Ostertagia spp, but activity against Trichostrongylus axei remained variable at this dose level. Efficiency against Trichuris ovis ranged from 76 to 100% at a dose rate of 10 mg/kg. The drug was 94 to 100% effective against 7-day old and 14-day old H. contortus , intestinal Trichostrongylus spp and O. colun bianum infections, and 83 to 89% effective against 14-day old Ostertagia spp and T. axei , at a dose rate of 5 mg/kg. Seven-day old Ostertagia spp larvae were highly resistant at a dose rate of 10 mg/kg, while activity against T. axei infections of the same age appeared variable at 5 and 10 mg/kg.
In cattle, subcutaneous treatment at dose rates of 1.5 mg/kg and above, and oral treatment at 7.5 mg/kg, were 93 to 100% effective against adult Haemonchus placei , intestinal Trichostrongylus spp, Nematodirus helvetianus, Cooperia spp and Oesophagostomum radiatum , and 84 to 98% effective against Ostertagia ostertagi . Against Trichostrongylus axei , a rate of 5 mg/kg subcutaneously was 83% effective, and a rate of 7.5 mg/kg orally 97% effective, while these dose rates gave 88 to 100% clearance of adult Dictyocaulus viviparous . 相似文献
In sheep, oral dose rates of 5 mg/kg and above were 94 to 100% effective against adult Haemonchus contortus , intestinal Trichostrongylus spp, Nematodirus spp, Oesophagostomum columbianum, O. venulosum and Chabertia ovina . A dose rate of 7.5 mg/kg was required for consistently high activity against Ostertagia spp, but activity against Trichostrongylus axei remained variable at this dose level. Efficiency against Trichuris ovis ranged from 76 to 100% at a dose rate of 10 mg/kg. The drug was 94 to 100% effective against 7-day old and 14-day old H. contortus , intestinal Trichostrongylus spp and O. colun bianum infections, and 83 to 89% effective against 14-day old Ostertagia spp and T. axei , at a dose rate of 5 mg/kg. Seven-day old Ostertagia spp larvae were highly resistant at a dose rate of 10 mg/kg, while activity against T. axei infections of the same age appeared variable at 5 and 10 mg/kg.
In cattle, subcutaneous treatment at dose rates of 1.5 mg/kg and above, and oral treatment at 7.5 mg/kg, were 93 to 100% effective against adult Haemonchus placei , intestinal Trichostrongylus spp, Nematodirus helvetianus, Cooperia spp and Oesophagostomum radiatum , and 84 to 98% effective against Ostertagia ostertagi . Against Trichostrongylus axei , a rate of 5 mg/kg subcutaneously was 83% effective, and a rate of 7.5 mg/kg orally 97% effective, while these dose rates gave 88 to 100% clearance of adult Dictyocaulus viviparous . 相似文献
11.
S A Michael A H Refaii W H Mansour M K Selim A J Higgins 《The Veterinary record》1979,104(15):338-340
Oxfendazole liquid suspension (Systamex; Wellcome) was administered orally at the dose of 4.5 mg per kg to 800 indigenous Egyptian sheep clinically affected with Dictyocaulus filaria, Moniezia expansa, Haemonchus contortus, Ostertagia circumcincta, Nematodirus spp, Trichostrongylus axei, Cooperia curticei, Trichuris ovis and Oesophagostomum spp. A 100 per cent clearance was recorded for all parasites with the exception of T ovis which were markedly reduced in number. 相似文献
12.
Four experiments in 1978-79, and 2 in 1982 designed to define the optimum dose rate of dermally applied formulations of levamisole are described. These experiments showed that the absorption of levamisole with resultant blood levels and anthelmintic activity is strongly influenced by temperature. In warm to hot conditions percutaneous absorption is rapid and high blood levels with high anthelmintic activity against Haemonchus placei, Ostertagi sp, Trichostrongylus sp, Cooperia sp, Oesophagostomum radiatum, O. venulosum and Dictyocaulus viviparus result from dose rates of 10 mg/kg or more. In cold weather the high efficacy against H. placei, Cooperia sp, and Oesophagostomum sp is unchanged, but efficacy against Ostertagia sp, T. axei and D. viviparus decreases to the extent that a mean dose rate of 20 mg/kg (range 15 to 25 mg/kg) is necessary if the anthelmintic activity of dermally applied levamisole is to match that of either parenterally or orally administered material. These anthelmintic data are supported by the levamisole blood profile which in winter months, peaks at a figure of one quarter or less of that obtained from a similar dose rate in warm conditions. The implications of this variability in action are discussed. 相似文献
13.
C. Curr 《Australian veterinary journal》1977,53(9):425-428
A series of trials to establish the anthelmintic efficiency of levamisole, when applied dermally to calves, is described. The levamisole base was formulated in a suitable solvent system at 100 g/l and applied dermally at a dose rate of 8 mg base/kg. This gave efficiencies of 97.1-100%, 88.5-100%, 100%, 98.7-100% and 89.2-100% against adult Haemonchus placei, Ostertagia spp, Cooperia spp, Oesophagostomum radiatum and Trichostrongylus axei, respectively. Activity against the immature stages of H. placei was recorded at 100%, and against immature Cooperia spp the range was 96.3-100%. Extremely variable results were obtained against immature Ostertagia spp, efficiency ranging from 0% to 100%. Efficiency against adult Dictyocaulus viviparus was in the range of 84-100%. The potential advantage of a dermally applied anthelmintic is discussed. 相似文献
14.
Two worm-free calves were allowed to graze on irrigated pasture with a naturally infected herd for each of 34 one-month periods from November 1979 to August 1982. After each grazing period, the calves were transferred to a cement-floored pen for 3 weeks and then were euthanatized and necropsied. Ostertagia ostertagi and Cooperia oncophora were the most prevalent species of nematodes recovered. Adults and larvae of Ostertagia spp and Cooperia spp were most numerous in winter and spring and least numerous during summer. The proportions of Ostertagia spp that were inhibited as fourth-stage larvae increased in late fall, peaked from March through April, and then decreased to low values during summer. The maximal inhibition in 1980, 1981, and 1982 was 72, 65, and 62%, respectively. The number of larval Cooperia spp was highest in winter months and, except for one grazing period when 55% of the Cooperia spp were larvae, the total numbers represented less than 15% of the nematode population during all grazing periods. Other nematodes encountered were Trichostrongylus axei, Haemonchus spp, O lyrata, and O occidentalis in the abomasum; C surnabata, C punctata, Nematodirus helvetianus, T colubriformis, and Bunostomum phlebotomum in the small intestine; and Oesophagostomum venulosum and Trichuris ovis in the large intestine. 相似文献
15.
The effectiveness of the new anthelmintic fenbendazole (Panacur) produced by Hoechst, W. Germany, was tested in cattle naturally invaded by gastro-intestinal and pulmonary nematodes. The single dose of 5.7 mg per kg or 7.5 mg per kg body weight administered either in the form of a 10% suspension or in pellets containing 1.5% of the active substance gave 100% intenseffectiveness and 100% extenseffectiveness in the control of Dictyocaulus viviparus, Haemonchus contortus, Trichostrongylus spp., Ostertagia spp., Oesophagostomum spp. and Cooperia spp. The animals tolerated the administration of both drug forms without showing any undesirable symptoms. 相似文献
16.
McKenna PB 《New Zealand veterinary journal》1989,37(2):62-64
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 possible future options for controlling anthelmintic resistant sheep trichostrongylids is briefly discussed. 相似文献
17.
Anthelmintic activity of a pour-on formulation of levamisole, applied during warm weather (16 degrees to 36 degrees C) at 10 mg/kg bodyweight, was evaluated in groups of naturally parasitised calves. This activity was compared to that obtained in similar groups of calves treated in the winter (-4 degrees to +7 degrees C). Controlled efficacy of the pour-on formulation was determined for each season by comparing mean worm burdens in treated calves sacrificed seven to nine days after treatment to non-treated controls. In these trials, burdens of Bunostomum phlebotomum, Cooperia species, Haemonchus placei, Nematodirus species, Oesophagostomum radiatum, Ostertagia ostertagi and Trichostrongylus axei in treated calves were reduced by 83.3 to 100 per cent in the summer and 89.2 to 100 per cent in the winter. Field investigations at nine locations across the USA compared changes in faecal egg counts for cattle treated and evaluated during warm summer months (27 degrees to 36 degrees C) to those treated during cold winter months (-18 degrees to +10 degrees C). Overall, faecal egg counts were reduced by 90.2 per cent in the summer trials and 94.0 per cent in the winter trials. The results of these trials indicate that there is no seasonal variation in the anthelmintic activity of this pour-on formulation of levamisole. 相似文献
18.
The efficacy of albendazole in removing gastrointestinal nematodes and tapeworms was studied in 16 treated and 16 untreated (control) beef calves. The anthelmintic was administered as an oral drench at a dose level of 5 ml/45.5 kg of body weight (5 mg/kg). Percentage of efficacy against the various genera was: Trichostrongylus axei, Oesophagostomum radiatum, and Moniezia-100.0; Haemonchus placei, Cooperia spp, and Trichostrongylus colubriformis - greater than 99.0; Ostertagia ostertagi -98.3; and Bunostomum phlebotomum -96.2. Efficacy against Trichuris was 20.2. Efficacy against immature nematodes in the abomasum and small intestine was high, 91.9 and 86.4, respectively, but total numbers of nematodes were not large. Efficacy against immature stages in the cecum and remainder of the large intestine was 48.5. Signs of toxicosis were not observed in calves treated with albendazole. 相似文献
19.
McKenna PB 《New Zealand veterinary journal》1986,34(6):94-96
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, statistically significant antiparasitic activity was evident in animals five and ten days after treatment with ivermectin given by injection and five days after treatment with ivermectin given orally. The possible relevance of these results to parasite control and the potential for selecting for anthelmintic resistance are briefly discussed. 相似文献
20.
R K Reinecke R Kirkpatrick L Swart A M Kriel F Frank 《The Onderstepoort journal of veterinary research》1987,54(1):27-38
Regular worm counts were done post-mortem on sheep that had grazed on Kikuyu pastures at the Elsenburg Research Station near Stellenbosch, a winter rainfall region. Major species were Trichostrongylus colubriformis, Trichostrongylus axei, while Ostertagia circumcincta was usually present in large numbers. Minor species were Haemonchus contortus, Nematodirus spathiger, Dictyocaulus filaria, Oesophagostomum venulosum, Trichuris spp., Chabertia ovina and larvae of the arthropod Oestrus ovis. Muellerius capillaris caused the formation of nodules in the lungs but were not counted. The trial started in April 1982 and was concluded in March 1984. One hundred and four sheep died or were slaughtered and 99 were examined post-mortem during this period. Total worm burdens rose to a peak of 88,763 (range 67,281-124,735) worms in March 1983, i.e. sheep mortality was such that the flock had to be treated with an anthelmintic in April 1983 to prevent further losses. Kikuyu pastures provide shade, form an excellent mat, the humus layer under the grass retains moisture and is an excellent incubator for preinfective larvae and a protector for infective larvae. If these qualities are combined with more than 100 mm of rain in spring and summer, Kikuyu pastures are a paradise for the free-living stages. 相似文献