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1.
Anthelmintic resistance by gastrointestinal nematodes of sheep continues to be an issue of global interest. While the recent introduction in some countries of one or two new anthelmintic classes (amino-acetonitrile derivatives [AAD] and spiroindoles [SI]) has been welcomed, it is important that there is no relaxation in parasite control and the management of drug resistance. Monepantel (an AAD) was the first new anthelmintic to be approved for use (New Zealand, 2009) and was followed a year later in the same country by a combination of derquantel (a SI) and abamectin. The present study determined the efficacy of the new anthelmintic products and abamectin against fourth-stage larvae of macrocyclic lactone-resistant Teladorsagia spp. in lambs. Efficacies were calculated by comparing post-mortem nematode burdens of treated animals with those of untreated control sheep, and were 98.5, 86.3 and 34.0% for monepantel, abamectin/derquantel and abamectin, respectively. The nematode burdens of monepantel- and abamectin/derquantel-treated sheep were significantly lower than those sheep treated with abamectin and the untreated controls. Similarly, the burden of the monepantel group was significantly lower than that of the abamectin/derquantel group. These findings provide an opportunity to reinforce the recommendation that farmers and animal health advisors need to know the resistance status of nematode populations on subject farms to ensure effective control programs are designed and implemented. Such control programs should include an appropriate choice of anthelmintic(s), monitoring parasite burdens for correct timing of treatments, and pasture management to reduce larval challenge balanced with the maintenance of drug-susceptible populations in refugia.  相似文献   

2.
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 naturally acquired nematode infections as determined by faecal nematode egg counts and larval cultures. The cattle were allocated on Day 0 (Trial 1) or Day 6 (Trial 2) on a stratified random basis according to bodyweight to one of two treatments: untreated control or eprinomectin (0.5% w/v) applied topically at 1 ml/10 kg bodyweight. Necropsies were undertaken on Days 14 and 15 and total nematode counts were done. In Trial 1, cattle treated with eprinomectin had significantly (p < 0.05) fewer Cooperia spp. and O. ostertagi than the controls. Larvae of H. contortus and T. colubriformis did not establish. In Trial 2, cattle treated with eprinomectin had significantly (p < 0.05) fewer of the following parasites than the controls: Haemonchus spp. (adult), Cooperia surnabada (adult), C. oncophora (adult), Cooperia spp. (L,), Ostertagia lyrata (adult), O. ostertagi (adult), Oesophagostomum spp. (adult), T. avei (adult and L1) and Trichuris spp. (adult). Reductions of 100% were observed for Capilfaria spp. (adult), D. viviparus (adult and L,), and Nematodirus helvetianus (adult), but these were not statistically significant (p > 0.05) because four or fewer control animals were infected with these parasites. In Trial 2, efficacies of greater than 99% were observed against all species for which moderate to high burdens occurred in the untreated controls. These findings indicate that eprinomectin in a topical formulation is a highly effective nematocide in cattle.  相似文献   

3.
Helminth-free dogs and cats were experimentally infected with protoscoleces of Echinococcus multilocularis and used in controlled trials for efficacy evaluation of the cestodicide epsiprantel. In two separate trials each 4 dogs were treated at day 20 post infection (p.i.) with average oral dosages of 5.1 (4.9-5.3) and 5.4 (5.2-5.8) mg/kg body weight (b.w.) epsiprantel, respectively, and necropsied at day 24 p.i. Among each 4 dogs of the two untreated control groups all animals were infected and had high intestinal worm burdens with averages of 33.575 and 100.725 E. multilocularis specimens per animal (individual worm burdens in group Ib 59,500-149,800, group IIb 20,500-43,200); in the two groups of treated dogs the average worm burdens were reduced by 99.6 and 99.9%. Among 8 treated dogs 4 were helminth-free, the other 4 had residual worm burdens (10-70 in 3 dogs, 1480 in 1 dog). In each 5 cats single oral treatments with average doses of 2.7 (2.7-2.8) and 5.5 (5.5-5.5) mg/kg b.w. epsiprantel were 100% effective against E. multilocularis 20 days p.i. and eliminated the worm burdens from all 10 animals. In the untreated group of 5 cats the average worm burden was 2864 per animal (individual worm burdens 20-6830). Side effects of the drug treatment were not observed. The results of the study show that in single therapeutic dosages recommended by the producer (dogs 5.5 mg, cats 2.75 mg/kg b.w.) epsiprantel eliminates E. multilocularis to over 99% or completely, but residual worm burdens may persist in some animals.  相似文献   

4.
The study was conducted in a peri-urban agricultural system at Botshabelo, a city in the south-eastern Free State. A questionnaire survey revealed that 88.5% of cattle farmers in the area experienced problems related to ticks and tick-borne diseases. Because of the cost of commercial acaricides the Botshabelo farmers use alternative, cheaper methods of tick control, including the application of used engine oil. The specific aim of the study was to determine whether used engine oil can effectively control ticks on cattle. From March to August 1996 the tick burdens of ten control animals and six animals treated by their owner with used engine oil were compared. The total tick burdens for the 6 month period differed significantly between the two experimental groups. The efficacy of the used engine oil on the treated group varied between 15.1% and 64.8% with a mean of 38.1%. Although commercial acaricides can be more cost-effective, the application of used engine oil can be useful to reduce tick numbers on cattle during periods of peak abundance. Another advantage in that the use of the oil will not influence existing endemic stability of Anaplasma marginale and Babesia bigemina infections because of the residual tick burdens after treatment.  相似文献   

5.
A granulated formulation of fenbendazole was tested in a total of 23 treated and control, pregnant, parasite-free Beagle bitches experimentally infected with Toxocara canis and Ancylostoma caninum. The drug was administered to each treated bitch once daily in canned dog food at a dosage of 50 mg/kg body weight. Each of 2 treatment regimens tested was initiated on the 40th day of pregnancy. One regimen involved daily treatment continuing through the 14th postpartum day, and it resulted in 89% fewer ascarids and 99% fewer hookworms in pups born to medicated bitches, as compared with pups born to unmedicated controls. The other regimen of treatment, which was stopped on the day of parturition, was less effective in reducing ascarid and hookworm burdens (64% and 88% reductions, respectively). Three to 5 bitches from each of the treatment and control groups were allowed to whelp a 2nd litter without further treatment or further exposure to parasite infections. Hookworm burdens in 2nd-litter pups born of bitches that had initially received fenbendazole through the 14th postpartum day were significantly lower (P < 0.01; 85% reduction), when compared with the 2nd-litter control pups. All other parasite burdens were not significantly different. It was concluded that granulated fenbendazole is effective in reducing burdens of Ancylostoma caninum and Toxocara canis in newborn pups when the bitch is treated during the last third of pregnancy, especially when treatment (50 mg/kg/day) extends from the 40th day of pregnancy through the 14th postpartum day.  相似文献   

6.
The cumulative total helminth parasite burdens of ranch calves during their first seven months of life on the North-eastern Mountain Grassland of South Africa were determined during two consecutive years. Trichostrongylus axei was the most abundant nematode parasite followed by Cooperia spp. and Ostertagia ostertagi. Haemonchus spp. occurred in relatively low numbers and its development was significantly inhibited. The total helminth parasite burdens of the calves ranged from 681 to 7,269 with a mean of 4,405.  相似文献   

7.
Viability and in vitro and in vivo activities of freeze-dried conidia of the predatory fungus Arthrobotrys robusta (I-31) were evaluated against infective larvae (L(3)) of Ancylostoma spp. in dogs. A. robusta conidia were lyophilized and stored at 4°C for a month. Freeze-dried conidia were diluted to 1×10(3)conidia/ml and tested in vivo. The treated group consisted of a solution containing conidia (1ml) and 1000 Ancylostoma spp. (L(3)) placed on Petri dishes plated with 2% water-agar (2% WA), at 25°C, in the dark for 10 days. The control group consisted of 1000 Ancylostoma spp. L(3), plated on 2% WA. After 10 days, Ancylostoma spp. L(3) from both the treated and the control groups were recovered and counted. The in vivo test was performed on two dogs by administering a single oral dose of freeze-dried conidia (1.5×10(5)) in aqueous solution to one animal and only water to the other. Fecal samples were collected at 12, 24 and 48h after the treatments, plated 2% WA plates and incubated at 25°C for 15 days. A thousand Ancylostoma spp. L(3) larvae were spread on these plates. At day 15, infective L(3) recovered from the treated and control groups were counted. In the in vitro test, A. robusta was able to survive the freeze-drying process, grow in the plates, form traps and capture Ancylostoma spp. L(3). There was a 75.38% decrease in the number of infective larvae recovered from the treated group. The in vivo test showed that freeze-dried A. robusta conidia survived the passage through the gastrointestinal tract of the treated dog, was able to grow in the plates and capture Ancylostoma spp. L(3), reducing the number of recovered L(3) (p<0.01). Freeze-drying can be an alternative method for conservation of conidia of nematophagous fungi.  相似文献   

8.
The immediate as well as the persistent anthelmintic efficacies of topically applied eprinomectin were evaluated in goats against induced infections with Teladorsagia circumcincta (2800 L3) and Trichostrongylus colubriformis (6000 L3). Twenty-three culled dairy goats were allocated to the following groups: control animals (group 1), animals treated 21 days prior to nematode infection (group 2), animals treated 7 days prior to nematode infection (group 3) and animals treated 21 days after nematode infection (group 4). Eprinomectin was applied at twice the cattle dose rate (1.0 mg/kg BW). According to the groups, necropsies were undertaken 28 days after nematode infection (groups 1-3) or 14 days after the anthelmintic treatment (group 4). Worm counts were determined for abomasum and small intestine. The curative anthelmintic efficacy of eprinomectin at 1.0 mg/kg BW on existing worm burdens was 100% against T. circumcincta and T. colubriformis. Quite similar worm burdens reductions were observed when eprinomectin was administered 7 days before infection whereas they were only 52.4 and 17.8% for T. circumcincta and T. colubriformis, respectively, for an administration of the drug 21 days prior to the nematode infection.  相似文献   

9.
OBJECTIVE: To evaluate imidacloprid and the combination of lufenuron and pyrethrin to control flea infestations in households with pets. ANIMALS: 37 dogs and 19 cats in 34 flea-infested households. PROCEDURE: Households were assigned randomly to 1 of 2 groups. Pets in group 1 were treated topically with imidacloprid on day 0, then once a month for 90 days. Pets in group 2 were given lufenuron orally on day 0 and at monthly intervals for 90 days and also were treated topically with a pyrethrin spray every 1 to 2 weeks throughout the study. Flea numbers in homes were assessed by use of intermittent light traps, and flea burdens on pets were assessed using visual area counts done once a week during the first month, then every other week. RESULTS: One application of imidacloprid reduced flea burdens on pets by 96 and 93.5% on days 7 and 28, respectively, compared with day-0 burdens. Following 3 applications, flea burdens on pets and in homes were reduced by 98.8 and 99.9%, respectively. Lufenuron and pyrethrin spray reduced flea numbers on pets by 48.9 and 91.1% on days 7 and 28, respectively. By the end of the study, this combination reduced flea burdens on pets and in homes by 99.2 and 99.7%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Imidacloprid applied topically or lufenuron administered orally along with a topically applied pyrethrin spray were effective in eliminating fleas on pets and in homes. Flea control can be achieved with topical application of adulticides or oral administration of insect growth regulators without concomitant treatment of the surroundings.  相似文献   

10.
Strategic application of moxidectin pour-on (Cydectin) was evaluated in Uganda for its effect on pasture larval counts and gastrointestinal nematode faecal egg counts in village cattle kept under tethering (semi-intensive) grazing management. The strategic deworming schedule involved treating cattle twice at an interval of 2 months, at the end of the 1st wet season and during the 2nd wet season. Two groups of 30 cattle, each consisting of a treated and a control group, were examined for nematode infections every 4 weeks from June 1999 to January 2000. The treated group had significantly lower mean faecal egg counts than the untreated groups (t-value = 2.47, P < 0.05). Generally, the pasture larval counts on treated farms were lower than on untreated ones, but not significantly so (t-value = 2.22, P = 0.068). Pasture larval counts with different nematode species on treated farms were lower than on untreated ones, but the differences were not significant for Haemonchus spp. (t-value = 1.68, P = 0.145), Oesophagostomum spp. (t-value = 1.87, P = 0.111), Trichostrongylus spp. (t-value = 1.93, P = 0.102), Dictyocaulus spp. (t-value = -0.74, P = 0.485) and Cooperia spp. (t-value = -1.00, P = 0.356). Treated farms did, however, have significantly lower pasture larval counts of Bunostomum spp. (t-value = 4.64, P < 0.05). This study has revealed that the application of moxidectin pour-on on cattle has an effect on faecal egg count and pasture contamination under the tethering grazing system. Moxidectin pour-on and the strategic deworming schedule evaluated here could be used for the control of gastrointestinal nematode infections in cattle by small-scale farmers who practise tethering or semi-intensive grazing management in Uganda and other tropical countries, especially where there is a bimodal rainfall pattern.  相似文献   

11.
The morantel sustained release bolus was administered at turnout to first-season grazing calves in order to assess its efficacy in the seasonal control of infection by nematode parasites in Ireland. The pastures grazed by control calves showed a marked increase in gastrointestinal trichostrongylid infective larvae by September, while numbers of infective larvae on pasture grazed by bolus-treated calves remained at a low level throughout the grazing season. In consequence, the controls showed significantly higher worm egg counts in late season and significantly higher worm burdens (mainly Ostertagia spp) at necropsy carried out in November on representative number of principal animals selected from each group. These reduced worm burdens were attributed to the suppression of egg output during the early part of the season as a result of treatment with the morantel sustained release bolus at turnout in the spring. Pasture contamination with Dictyocaulus viviparus larvae was present on all treatment pastures. The bolus-treated calves however were subjected to an increase in D. viviparus infection which occurred on their pasture in late season after the active life of the bolus had expired. It was concluded that bolus treatment delayed (rather than prevented) the buildup of D. viviparus infection on the pasture by 60-90 days.  相似文献   

12.
The aim was to determine the persistent efficacy of copper oxide wire particles (COWP) against Haemonchus contortus in sheep, using the harmonization guidelines protocol. Thirty-six male lambs (2 months old) reared free of gastrointestinal nematodes were used (average body weight of 10.8±3.8kg). Before and for the duration of the study, lambs were kept in raised cages with slatted floors and were offered ad libitum a complete mixed diet. Animals were divided into six groups (n=6): one non-treated control group (G0) and five groups treated with one COWP capsule (1.7g of copper oxide; Copinox(?)). Animals in each group were treated on pre-defined dates before the artificial infection was applied: days -35 (G1), -28 (G2), -21 (G3), -14 (G4) and -7 (G5). On day 0 animals were infected with 3700 H. contortus infective larvae per animal. Animals were humanely slaughtered between days 22 and 23 post-infection. The abomasums were individually washed to obtain the contents. These organs were subjected to separate artificial digestions. Adult parasites were counted from the abomasum contents and the larvae from the digested material. Worm burden geometric means were calculated for each group. A significant worm burden reduction in either of the treated groups (G1, G2, G3, G4, and G5) compared to the control (G0) was considered as persistence of the anthelmintic effect. Copper levels were determined from individual liver samples of each animal. The geometric mean worm burden of the control group (G0) was 1959. Compared to the control, worm burdens geometric means were significantly reduced in groups G1 (1108), G4 (528) and G5 (1063) (P<0.03). Efficacies in G1, G4 and G5 were 43.4%, 73.0% and 45.7% respectively. No significant reduction was found for G2 (1342) and G3 (1430). A larger quantity of Cu was found in the livers of treated animals compared to the control group (P<0.05) except for G3 (P=0.06). A negative association between Cu liver content and worm burdens was found (r=-0.42, P<0.05). Live weight gain was similar in all groups and no clinical or post-mortem manifestations of Cu toxicity were recorded in treated animals.  相似文献   

13.
OBJECTIVE: To determine effects of topical antimicrobial and antimicrobial-corticosteroid preparations on the ocular flora of horses. animals: 40 horses. PROCEDURE: One eye was treated 3 times daily for 2 weeks with one of the following ointments: (1) neomycin-bacitracin-polymyxin B, (2) 0.6% prednisolone-0.3% gentamicin, (3) neomycin-polymyxin B-0.05% dexamethasone, or (4) treated (artificial tears) control. Contralateral eyes of treated control eyes served as untreated control eyes. Corneal and conjunctival specimens for bacterial and fungal cultures were collected prior to initiation of treatment, after 1 and 2 weeks of treatment, and 2 weeks after concluding treatment. Changes in culture growth quantity scores of bacterial and fungal species were analyzed. RESULTS: The most common species before treatment were the following: gram-positive bacteria included Streptomyces spp (66%), Staphylococcus spp (46%), Bacillus spp (32%), and Streptococcus spp (32%); gram-negative bacteria included Moraxella spp (28%), Escherichia coli (24%), Acinetobacter spp (18%), and Enterobacter spp (14%); and fungi included Aspergillus nidulans (56%), Cladosporium spp (32%), and Aspergillus fumigatus (22%). In all groups, the percentage of positive bacterial culture results, growth quantity score of gram-positive bacteria, and number of bacterial species isolated decreased at week 1 and increased at week 2, whereas growth quantity score of gram-negative bacteria decreased throughout treatment. Differences were not significant among groups. Fungal growth quantity score decreased during treatment in all groups. Repopulation of bacterial and fungal species occurred. CONCLUSIONS AND CLINICAL RELEVANCE: All interventions decreased the number of microorganisms. Repopulation of normal flora occurred during and after treatment.  相似文献   

14.
The efficacy of the first of a new generation of intraruminal devices for cattle, the morantel sustained release trilaminate, was assessed in two field trials. In each trial the animals were divided into a control group and a treated group. The device was administered to each calf before turn out in the spring and the reduction of gastrointestinal parasitism resulted in a substantial reduction in the level of pasture contamination with infective helminth larvae later in the season. Compared with the control calves the treated calves had a 94 per cent reduction of worm burdens acquired over the entire grazing season in the first trial, despite the controls being treated for clinical disease in September. In the second trial four anthelmintic treatments were administered to the control calves during the grazing season, but nevertheless a 64 per cent reduction of worm burdens in the treated group compared to the control group was recorded. The control of parasitic infection by the sustained-release devices resulted in mean weight gain advantages of 28.3 kg and 34.7 kg by the treated animals in the first and second trials respectively.  相似文献   

15.
Three on-farm studies were conducted in Nicaragua during three consecutive years (1999–2001) to assess the impact of natural helminth infections on growth performance of free-range chickens aged 3–4 months. On all participating farms, half of the chickens were treated regularly with anthelmintics (Trifén avícola – a combined formulation of piperazine, phenothiazine and dichlorophen – or albendazole) to express the growth potential of non-infected birds, whereas the other half served as non-treated controls. In 1999, treated chickens had a 39% higher weight gain compared to the control group 6 weeks after the first treatment on 15 farms. In 2000 and 2001, treated chickens had similar weight gain as the control group 10 weeks after the first treatment on 7 farms and 12 farms, respectively. The main reason for the very-different weight gain figures seems to be the weather conditions. In 1999, the study site experienced a rainy season with precipitation far above average, whereas in 2000 and 2001 the rainy seasons had precipitations far below average. Based on these findings, routine use of anthelmintics in the study area would only be recommended in wet years when production losses due to helminth infections seem to be pronounced.

In 2001, the study set-up included an assessment of the effect of protein supplementation (soybean) on growth on six farms. Supplemented chickens (treated and non-treated with anthelmintics) had 17% higher weight gain than non-supplemented. Protein supplementation affected neither worm burdens nor faecal egg counts for any of the studied helminths.

The post-mortem examinations showed that Trifén reduced burdens of Ascaridia galli, Heterakis gallinarum, and cestodes (efficacies of 100, 100 and 67%, respectively). Albendazole reduced burdens of H. gallinarum (efficacy of 100%). Efficacies against other helminths were difficult to assess due to low worm burdens. Chickens treated with albendazole had lower Ascaridia and Heterakis faecal egg counts than non-treated chickens.  相似文献   


16.
Gastrointestinal nematode parasite burdens were monitored in a herd of field-grazed cattle from weaning to 2 years old to allow observations to be made on the dynamics of burdens of arrested Ostertagia spp. and Cooperia oncophora. Arrested Ostertagia spp. accumulated in the herd over their first autumn and winter to reach a peak in late winter/spring (August-October). From October until late January they declined at a rate comparable to that at which they had accumulated. Numbers continued to decline at a slower rate until the following autumn (May) when they began to increase again. Observations on the decline of worm burdens in a group of animals which had been moved from pasture to worm-free conditions in October indicated that intake of infective larvae over late spring/summer contributed little to the number of arrested Ostertagia spp. in the herd. No clinical Type II ostertagiosis was observed in the field-grazed animals over the time of decline of the arrested worm burden, nor was there an increase in the number of adult Ostertagia spp. present. However, two of the animals removed from pasture to worm-free conditions developed Type II ostertagiosis approximately a month after the move. Worm burdens of successive groups of "tracers" grazed with the herd every 2 months indicated that there was a small seasonal increase in the propensity of Ostertagia spp. for arrested development. However, estimated accumulation rates of arrested larvae calculated from tracer worm burdens, suggest that this seasonal increase in propensity was not adequate in itself to account for the accumulation rate observed in "resident" animals of the herd. No comparable accumulation of arrested C. oncophora took place in resident animals over the first autumn and winter of the trial despite the fact that tracer worm burdens over this period indicated a marked seasonal increase in the propensity for arrested development by this species.  相似文献   

17.
In 2 trials, the efficacy of an in-feed preparation of ivermectin was evaluated in 40 pigs naturally infected with endoparasites and Sarcoptes scabiei var suis. Treated pigs (n = 10 in each trial) were fed a ration containing 2 ppm ivermectin for 7 days, followed by consumption of a nonmedicated ration for the remainder of the trial. Control pigs (n = 10 in each trial) were fed a complete, nonmedicated ration for the duration of the trial. Pigs in trial A were monitored for 14 days after treatment; those in trial B were monitored for 35 days after treatment. In trial A, treatment efficacy of ivermectin was 100% against Ascaris suum, Physocephalus sexalatus, Oesophagostomum dentatum, O brevicaudum, Metastrongylus spp; 99.8% against Ascarops strongylina; 90.9% against Trichuris suis; and 13.1% against Macracanthorhynchus hirudinaceus. At the terminus of the trial, statistically significant (P less than 0.05) differences were observed between numbers of treated and control pigs infected with A suum, Ascarops strongylina, and Oesophagostomum spp. On posttreatment day 14, S scabiei were not found in any scrapings taken from treated pigs, but were found in scrapings from 3 of 10 control pigs. The number of infested pigs in the treatment group was not statistically different from the number of infested pigs in the control group. In trial B, treatment efficacy was 100% for A suum and Metastrongylus spp; 96.9% for Ascarops strongylina; and 76.9% for M hirudinaceus. At the terminus of the trial, statistically significant (P less than 0.05) differences were evident between numbers of treated and control pigs infected with A suum, Ascarops strongylina, and Metastrongylus spp.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
The efficacy of the morantel sustained release bolus (MSRB) in reducing gastrointestinal parasitism in first season grazing calves was evaluated during the summer--autumn grazing seasons of 1982 and 1983 in western Oregon. Each of 38 calves (1982) and 40 calves (1983) were randomly assigned to either control or treatment groups which were given MSRB on the day of turnout onto pasture. Mean worm burdens from tracer calves grazed with treated animals in 1982 and 1983 showed overall reductions of 86.4% (P greater than 0.05) and 84.3% (P less than 0.01), respectively, compared to tracers grazed with controls. Ostertagia ostertagi, Cooperia oncophora and Nematodirus helvetianus were the primary nematodes collected at necropsy. Twelve full-season 1982 tracer animals (6 treated and 6 control) indicated an 88.1% (P less than 0.05) overall reduction in mean worm burdens. Mean fecal worm egg per gram (EPG) counts of treated animals reflected a reduction of 69% (P less than 0.05) in 1982 and 90% (P less than 0.05) in 1983. Autumn inhibition of O. ostertagi was observed. In the 1982 trial the control animals showed a slight mean weight gain advantage over the treated group from Day 84 until Day 160 (trial termination) when the mean difference was 7.9 kg. The final mean weight gain advantage of treated animals in 1983 was 13.5 kg (P less than 0.05). These trials demonstrated that the MSRB was an effective anthelmintic for reducing gastrointestinal parasitism in grazing calves and for decreasing pasture larval contamination.  相似文献   

19.
Studies are reported on the effect of anthelmintic treatment on the body weight gain and wool growth of ewes with subclinical helminth infections. The parasites involved were Fasciola gigantica and Ostertagia spp., together with some Haemonchus contortus, Trichostrongylus spp., and Dictyocaulus filaria. In 1 group, 5 sheep, which were treated twice with tetramisole at an interval of 4 weeks to remove gastro-intestinal nematodes and lungworms, showed an increase of 41% in weight gain and 3.2% in wool growth compared with an untreated group. Another group, which was treated with both tetramisole and rafoxanide to remove nematode and fluke infections, had a 143% increase in weight gain and 81% in wool growth compared with the control.  相似文献   

20.
In a survey of 52 cats from the Saskatoon area, Ollulanus tricuspis were found in 2 animals with burdens of 2308 and 533, respectively. Small burdens of the following helminths were also found: Physaloptera spp., Toxocara cati, Taenia spp., Dipylidium caninum, and Ancylostoma sp.  相似文献   

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