• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.347-352
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• 1995

The efficacy of closantel against naturally-acquired and experimentally-induced F hepatica and param-phistomes were administered once orally with closantel at the level of 5mg/kg body weight. In a double-checked fecal examination, cows treated with closantel did not contain F hepatica eggs in their feces at second week post-treatment(PT). At the third and fourth weeks PT, however, Fasciola eggs were found in the feces of 3 treated cows, resulting in a 97.7% efficacy. Of the 41 treated cattle, 30 were at various stages of gestation. No side effects were observed in any of the treated cows and congenital defects among calves born from the treated cows were not reported. Closantel was not effective against paramphistomes. In a separate experiment, 16 Holstein caves were experimentally infected with 300 F hepatica metacercariae each. F hepatica eggs were found in the feces of all infected calves by 14 weeks post-infection(PI). Calves were then treated at 18 weeks PI once orally with 5mg/kg body weight closantel. None of the treated calves contained F hepatica eggs in their feces at 2nd, 3rd or 4th week PT. Our results indicate that oral administration of closantel at the level of 5mg/kg body weight eliminated all mature F hepatica in the liver, while some of immature flukes survived to become adult and produce eggs.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.595-599
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• 1997

Male and female Sprague-Dawley rats 8 weeks of age were inoculated per os with 10 Fasciola hepatica metacercariae each. After the infection was verified by fecal examination, they were divided into four groups at 14 weeks post-inoculation; three groups were dosed orally at 10, 20 and 30mg/kg of closantel($Flukiver^{TM}$), a salicylanilide compound and the rest used as untreated control. Efficacy of closantel was monitored weekly by fecal examination of all infected animals starting during the second week post-treatment(PT) and continuing for three weeks. Closantel elicited 96.0, 86.9 and 87.4% efficacy in rats treated with 10mg/kg at the second, third and fourth week PT, respectively. It elicited a 100% efficacy in rats treated with 20 and 30mg/kg.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.575-585
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• 2000

This study was performed to observe the influence of host immune response on the chemotherapy of mice experimentally infected with Fasciola hepatica. Following immunosuppression with prednisolone or immunoenhancement with Freund's complete adjuvant(FCA), mice were experimentally infected with 3 Fasciola hepatica metacercariae and treated with closantel at 1 week post infection. In the group of mice infected with metacercariae alone, 2 mice of 10 were dead at 10 weeks post infection(20% mortality), and adult flukes were recovered from the liver and the peritoneal cavity of the remaining 8 mice(100% infectivity). In the group of mice treated with prednisolone and infected with metacercariae, 8 of 10 mice died before euthanasia with a mean time of death earlier than the control group (p<0.05). In the group of immunosuppressed mice infected with metacercariae and treated with closantel 20mg/kg, 4 of 10 mice died before sacrifice. In the group of mice infected and treated with closantel 20mg/kg, mortality and infectivity was 10% and 30%, respectively. Similar results were observed in mice infected and treated with closantel 5mg/kg which resulted in 10% and 50% mortality and infectivity, respectively. These results indicated that the efficacy of closantel treatment was decreased in immunosuppressed mice, while the pathogenicity was increased. In immunoenhanced mice infected with metacercariae, on the other hand, the efficacy of chemotherapy with both 5mg/kg or 20mg/kg closantel resulted in only 10% infectivity. The results shown in this study strongly suggest that a close interaction between chemotherapy against F hepatica with closantel and the host immune system exists. Considering that fascioliasis is a zoonosis, treatment regimen against the infection to immunosuppressed patients may require a concurrent prescription of an appro-priate immuno-enhancing adjuvant.

• Journal of the korean veterinary medical association
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• v.33 no.6
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• pp.342-344
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• 1997