Efficacy of fenbendazole against helminth parasites of poultry in Uganda

Summary Fenbendazole 4% (Panacur, Hoechst) administered in feed was used to treat chickens infected withAscaridia galli, Heterakis gallinarum andRailletina spp. It was also used to treatSyngamus trachea in broiler birds. There was a marked drop in helminth egg counts in the faeces on the second day of treatment and the faeces became negative by the seventh day after the last treatment. Post-mortem examination 15 to 21 days later showed that the drug was 100% effective againstAscaridia galli andHeterakis gallinarum at 10 mg/kg. However, for complete removal ofRailletina spp. 15 mg/kg was required. Similarly 20 mg/kg fenbendazole was effective againstSyngamus trachea. It was concluded that fenbendazole is suitable for the treatment of the important intestinal and tracheal worms of poultry, a dose of 15 to 20 mg/kg for 3 consecutive days being recommended for use under field conditions.

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Eficacia Del Fenbendazole Contra Helmintos De Aves Domesticas En Uganda

Presumen Se administró Fenbendazole 4% (Panacur, Hoechst) en el alimento, para tratar aves infectadas conAscaridia galli, Heterakis gallinarum y Railletina spp. También se utilizó la droga para tratar pollos de engorde infectados conSyngamus trachea. Hubo un descenso marcado en el conteo de huevos de helmintos al segundo día del tratamiento, y las heces fueron negatives 7 días después del último tratamiento. El examen pos-mortem 15 y 21 días después del tratamiento mostró que la droga fue 100% efectiva contraAscaridia galli y Heterakis gallinarum en dosis de 10 mg/kg. Sin embargo, para el control deRailletina spp. 1a dosis se incrementó a 15 mg/kg. Similarmente, 20 mg/kg de Fenbendazole fueron efectivas contraSyngamus trachea. Se concluye, que el Fenbendazole es efectivo contra el tratamiento de los principales parásitos intestinales y traqueales de las aves domésticas, en dosis de 15 a 20 mg/kg, administrado por días consecutivos, en casos de campo.

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Efficacite Du Fenbendazole Contre Les Helminthes Parasites Des Volailles En Ouganda

Résumé Le Fenbendazole 4 p. 100 (Panacur, Hoechst) administré dans l'alimentation a été utilisé pour le traitement de poulets infectés parAscaridia galli, Heterakis gallinarum etRailletina spp. Il a été également utilisé contreSyngamus trachea chez les oiseaux de chair. On a observé une baisse marquée dans la numération des oeufs dans les fèces dès le deuxième jour du traitement et ces fèces étaient devenues négatives le septième jour après le dernier traitement. L'examen post-mortem pratiqué de 15 à 20 jours plus tard a montré que le produit était efficace à 100 p. 100 contreAscaridia galli etHeterakis gallinarum à 10 mg/kg. Cependant, il a fallu en arriver à la dose de 15 mg/kg pour obtenir la complète élimination deRailletina spp. De même le Fenbendazole à la dose de 20 mg/kg a été effectif contreSyngamus trachea. Il en est conclu que ce produit convient pour le traitement des helminthes intestinaux et trachéaux des volailles, la dose de 15 à 20 mg/kg pendant 3 jours consécutifs étant recommandée lors de son utilisation sur le terrain.

     

Anthelmintic efficacies of fenbendazole, ivermectin, and levamisole against Nematodirus battus infections in lambs

Anthelmintic efficacies of fenbendazole, ivermectin, and levamisole were evaluated against naturally acquired infections of Nematodirus battus in lambs. Four groups of 10 lambs each were used. Oral administration of 8 mg of levamisole/kg of body weight or 5 mg of fenbendazole/kg significantly (P less than 0.01) reduced the degree of infection by N battus (adults) by greater than 99%. An oral formulation of 200 micrograms of ivermectin/kg was 98% effective (P less than 0.01). Numbers of other Nematodirus spp (including N filicollis and N spathiger) were significantly reduced.     

Efficacy of a drug combination of praziquantel, pyrantel embonate, and febantel against helminth infections in dogs.

Tablets containing praziquantel, pyrantel embonate, and febantel were tested for efficacy against helminths in dogs. A single treatment with this drug combination gave 100% reductions in Toxocara canis and Taenia hydatigena in experimentally induced infections in dogs. In dogs with naturally acquired infections, treatment gave > 97 to 98% reductions in fecal egg counts attributable to Toxascaris leonina, T canis, and Uncinaria stenocephala. Efficacy against Trichuris vulpis was > 92%.     

Immunity of ivermectin treated cattle to challenge from helminth parasites in the following season

Two groups of yearling cattle which had been treated with ivermectin either three and eight, or three, eight and 13 weeks after turn out to trichostrongyle contaminated pasture in their first grazing season were exposed in the following season to natural challenge with helminth parasites. To assess their immunity to this challenge each group shared a pasture with parasite naive first season calves. No anthelmintic treatments were administered at any time during the year. Throughout the grazing period the yearlings showed normal respiratory rates, negative faecal lungworm larval counts, and, relative to the calves, low faecal trichostrongyle egg counts. All the first season calves developed patent lungworm infections and on one occasion the mean respiratory rates of each group of calves were significantly greater than those of the yearling cattle. At the end of the grazing period, from early May until late September or October 1986, the cattle were removed from pasture and together with parasite naive controls challenged with either 10 or 22 third stage larvae of Dictyocaulus viviparus/kg bodyweight and necropsied between 18 and 23 days later. Although the experimental challenge resulted in relatively heavy lungworm infection of the naive controls, none of the yearlings and only three of the 11 calves which had been at pasture were found to be infected. However, large numbers of arrested fourth stage larvae of Ostertagia ostertagi were present in all the naturally infected yearlings and calves.     

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 483 during the study. This increase was similar to that of ewes treated with morantel (7 to 485 epg). The mean epg count of fenbendazole-treated ewes increased from 4 to 192 during the study. By the end of the study, the mean epg counts when expressed as a percentage of the pretreatment epg counts were 4% (ivermectin), 249% (fenbendazole), 627% (levamisole), and 630% (morantel). With the exception of the ivermectin-treated ewes, the epg count increased almost linearly in the ewes after the 2nd anthelmintic treatment. These data indicate that the gastrointestinal nematodes (including Haemonchus contortus) may have developed more resistance to levamisole and morantel than to fenbendazole. On the basis of the epg counts, resistance to ivermectin did not develop during the 4.5-month treatment period. The percentage of ewes shedding eggs after 2, 4, and 6 anthelmintic treatments was lowest for ewes treated with ivermectin (20%) and was similar (40%) for ewes treated with 1 of the other 3 anthelmintics. At the conclusion of the study, most of the ewes (90%) were shedding at least a small number of eggs, regardless of the anthelmintic treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Re-evaluation of ivermectin efficacy against equine gastrointestinal parasites.

Two trials were conducted to confirm the efficacy of ivermectin paste against endoparasites of horses. In these trials, 20 ponies were treated with ivermectin oral paste at 200 mcg x kg body weight once on Day 0, and 20 ponies served as unmedicated controls. The animals carried naturally acquired parasite infections as confirmed by pretrial fecal examination. The animals were necropsied for worm recovery on Days 14, 15 or 16. Parasites recovered were identified to species. Horses treated with ivermectin had significantly (P<0.05) fewer (>99.0% reduction) adult small strongyles (Coronocyclus spp including C. coronatus, C. labiatus, C. labratus; Cyathostomum spp including C. catinatum, C. pateratum; Cylicocyclus spp including C. ashworthi, C. elongatus, C. insigne, C. leptostomum, C. nassatus, C. radiatus; Cylicodontophorus bicoronatus; Cylicostephanus spp including C. asymetricus, C. bidentatus, C. calicatus, C. goldi, C. longibursatus, C. minutus; Gyalocephalus capitatus; Parapoteriostomum spp including P. euproctus, P. mettami; Petrovinema poculatum; Poteriostomum spp including P. imparidentatum, P. ratzii) and adult large strongyles (Strongylus edentatus, S. vulgaris; Triodontophorus spp including T. brevicauda, T. serratus; Craterostomum acuticaudatum) than the controls. Ivermectin was also highly effective (94% to >99%, P<0.05-0.01) against Gasterophilus intestinalis larvae, Habronema spp., Oxyuris equi, Parascaris equorum. The data from these two trials confirm that ivermectin paste administered to horses orally at 200mcg x kg(-1) continues to be highly effective for treatment and control of a broad range of small and large strongyle species as well as other species of gastrointestinal parasites.     

Controlled trials of fenbendazole and febantel in ponies with parascaris equorum infections

The activity of fenbendazole and febantel was evaluated in 12 pony foals whichwere inoculated with 2600 P. equorum eggs. The foals were not maintained free of parasites before or after inoculation. Once patent for P. equorum, the foals were randomly assigned to groups and treated one time intraorally with either 0.5 ml corn syrup/kg of body weight (controls; n=4), 10 mg fenbendazole/kg (n=4), or 6 mg febantel/kg (n=4). Foals were necropsied and examined for parasites 10 days after treatment. Fenbendazole and febantel were highly effective against adult and immature P. equorum. Grosslesions attributed to P. equorum were evident in all foals. P. equorum were not foundin any of the fenbendazole-or febantel-treated foals. The mean number of adult and immature P. equorum found in the controls was 66.8 (15–166) and 65.0 (21–147), respectively. Strongyle infections were insufficient for efficacy evaluations to be done. Neither anthelmintic was effective against mature Drasehia megastoma, mature Habronema majus, immature H. muscae, Gasterophilus intestinalis or late 4th-stage larvae of Strongylus vulgaris. Adverse side effects due to treatment were not observed.     

伊维菌素干混悬剂对绵羊寄生虫的驱杀效果与安全性研究

选择1．5～2．0岁自然感染线虫和外寄生虫绵羊150只，分别按体重0．1、0．2、0．3mg／kg剂量口服伊维菌素干混悬剂，同时设口服伊维菌素片剂对照。结果显示，口服伊维菌素干混悬剂0．2、0．3mg／kg组绵羊的消化道线虫虫卵转阴率分别为93．3％和100％，减少率分别为99．2％和100％；原圆科线虫幼虫转阴率分别为90．0％和100％，减少率分别为94．5％和100％；平均驱虫率分别为98．4％和99．9％；绵羊颚虱、绵羊足颚虱全部被杀死，羊蜱蝇的转阴率分别为83．3％和87．5％。口服0．1mg／kg组绵羊的线虫虫卵（幼虫）转阴率、减少率、驱虫率均次于0．2、0．3mg／kg剂量组，对绵羊颚虱、羊蜱蝇的杀虫率较低。绵羊口服0．5mg／kg伊维菌素干混悬剂未出现明显异常反应。表明伊维菌素干混悬剂与片剂有同等的驱虫效果与安全性。     

Anthelmintic efficacy of mebendazole suspension against induced helminth infections in South African sheep and cattle

Critical controlled tests were performed in 157 sheep (8 experiments) and 34 cattle (2 experiments) to evaluate the anthelmintic activity of mebendazole suspension, administered intraruminally via a stomach tube at a dosage rate of 15 mg of mebendazole/kg of body weight, against induced infections of immature and adult stages of commonly encountered nematode parasites in South Africa. In the sheep, the controlled efficacy of mebendazole suspension was good to excellent (90.1% to 100%) against all stages of Haemonchus contortus, Trichostrongylus colubriformis, Gaigeria pachyscelis, Ostertagia circumcincta, Nematodirus spathiger, and Chabertia ovina species. Mebendazole was also highly effective (97.3% to 99.9%) against 4th, 5th, and adult stages of Oesophagostomum columbianum and 5th-stage and adult Dictyocaulus filaria. Moderate activity was obtained (79.8% to 82.2%) against 3rd-stage O columbianum, 3rd- and 4th-stage D filaria, and 5th-stage and adult Strongyloides papillosus. In the cattle, mebendazole was effective (91.5% to 100%) against 4th-stage and adult H placei, Cooperia pectinata, Bunostomum phlebotomum, and Oesophagostomum radiatum species, but did not exhibit any appreciable activity (27.3% to 41.5%) against 4th-stage and adult O ostertagi.     

The efficacy of ivermectin against nematode parasites of White Fulani calves

Ivermectin was evaluated for anthelmintic activity in calves naturally infected with gastrointestinal helminths. Five of 10 calves were treated subcutaneously with ivermectin at 200 micrograms per kg body weight. One-hundred percent efficacy was indicated against adult and immature Haemonchus, Trichostrongylus, Bunostomum phlebotomum and Oesophagostomum radiatum. Adult Cooperia were also completely eliminated, and a 95.5% reduction was obtained for the immature forms; an 88.7% reduction was obtained for Trichuris spp.     

Safety and efficacy of ivermectin against ear mites (Otodectes cynotis) in ranch foxes

Efficacy of ivermectin at a dosage of 0.2 mg/kg of body weight was evaluated against naturally acquired ear mite (Otodectes cynotis) infestation in commercially raised ranch foxes (Vulpes fulva). Efficacy of ivermectin given sc twice at 3-week intervals was 97.4%. Toxicosis associated with drug treatment was not observed. Increased dosage of 1.0 mg/kg was given sc to 5 foxes each week for 6 consecutive weeks, and signs of toxicosis or illness were not observed after treatment.     

Efficacy of thiabendazole, mebendazole, levamisole and ivermectin against gullet worm, Gongylonema pulchrum: in vitro and in vivo studies

In vitro and in vivo studies were conducted to evaluate the effects of thiabendazole, mebendazole, levamisole and ivermectin against Gongylonema pulchrum. For in vitro assays, third-stage larvae (L3) incubated with the drugs were administered orally to mice and the ability of larvae to invade the gastric mucosa of the animals was examined. After incubation, only those larvae treated with high concentrations of levamisole (1 and 10 microg/ml) were tightly coiled with intestines exhibiting morphological abnormalities. Good dose-response data for the drugs tested was observed at the time of worm recovery from mice, with no worms recovered at the two highest concentrations of levamisole. In vivo efficacy of the drugs against adult worms was evaluated in six groups of three rabbits, each of which was infected with 30 L3 of G. pulchrum and treated with thiabendazole at 100 mg/kg for 3 days, mebendazole at 70 mg/kg for 3 days, levamisole as a single dose of 8 mg/kg, and subcutaneously injected ivermectin as a single dose of 0.2 mg/kg or vehicles of the drugs (control) at 4 months post-infection. Necropsy 14 days after treatment revealed that levamisole, mebendazole and ivermectin reduced worm burdens by 63.2%, 22.8% and 25.8%, respectively, with no reductions in worms observed with thiabendazole. The surviving worms were principally found in the esophagus with the remainder distributed among the buccal mucosa, the tongue, and/or pharyngeal mucosa in all groups. A number of morphologically abnormal eggs were observed within the uterus and ovijector in female worms recovered from the thiabendazole-treated group. These findings suggest that levamisole exhibits in vivo efficacy against G. pulchrum infection and that the larval invasion tests using mice could be used to screen for anthelmintic susceptibility of nematodes.     

Field efficacy of ivermectin, fenbendazole and pyrantel embonate paste anthelmintics in horses

Three anthelmintic pastes were compared in terms of their ability to suppress the output of parasite eggs in the faeces of 108 grazing horses at four sites in Britain; the horses were treated once with either ivermectin, fenbendazole or pyrantel. At each site, the horses grazed together throughout the trials which took place during the summers of 1985 and 1986. The median periods before parasite eggs reappeared in faeces were 70 days for ivermectin, 14 days for fenbendazole and 39 days for pyrantel embonate. Geometric mean faecal egg counts in the groups treated with ivermectin and pyrantel were significantly less (P less than 0.05) than in the fenbendazole group on days 21, 28, 35 and 42 after treatment. On days 49, 56, 63 and 70 the mean egg counts in the ivermectin group were significantly lower (P less than 0.05) than those in either of the other groups. The results indicated that in order to ensure minimal contamination of pastures, grazing horses treated with ivermectin paste would have required a second treatment approximately 10 weeks after the first, and to achieve similar control with fenbendazole or pyrantel embonate, a second treatment would have been required after approximately two weeks and six weeks, respectively.