The resistance of nematode parasites in sheep against anthelmintic drugs widely used in Western Turkey

Abstract

This study was carried out in seven sheep herds infected by gastro-intestinal nematodes in the Afyonkarahisar district (Western Turkey) from June to July 2005. Sixty sheep in each herd were distributed into 3 groups as anthelmintic treatment groups along with a control group containing 15 animals. The anthelmintic groups were treated with albendazole (7.5 mg/kg BW), oxfendazole (7.5 mg/kg BW)-oxyclosanide (15 mg/kg BW) combination and ivermectin (0.2 mg/kg BW-injectable). The faecal samples were collected before treatment and after 10 days of treatment. Nematode egg counts per gram of faeces (EPG) were examined in the faecal samples using the McMaster technique. To identify the genus, the faecal samples were cultured. The faecal egg count reduction test (FECR) was employed to determine the resistance. In ivermectin treated groups, the FECR% values and the lower confidence limits were estimated as A: 68.57(14.77), B: 46.42(22.47), C: 84.41(35.38), D: 95.23(61.64), E: 97.14(76.94), F: 65.21(80.46) and G: 91.66(31.69), respectively. In the A, B, C, F and G herds, statistical analysis showed that the FECR% values were less then 95% and the estimated lower confidence limits were less then 90%. In all herds, albendazole treated, oxfendazole-oxyclosanide treated and control group, there were no eggs in the feacal samples. In these groups, the FECR% values were 100. In ivermectin treated groups, the third stage larvae from the genera Haemonchus, Oesophagostomum, Trichostrongylus, Cooperia, Nematodirus and Ostertagia were detected in coprocultures before treatment and the larvae from the genera Haemonchus and Oesophagostomum were detected in post-treatment coprocultures in the resistant herds. In conclusion, there was no evidence of resistance in sheep gastro-intestinal nematodes against albendazole and oxfendazole-oxyclosanide; in contrast, the resistance against ivermectin was detected in five sheep herds in the Afyonkarahisar district.

Resistência anti-helmíntica de nematóides gastrintestinais em ovinos, Mato Grosso do Sul

“…A contagem média de 1.731 OPG, relatada nesse trabalho; com amplitude das médias, nos rebanhos, variando de 201 a 5.893 OPG (Quadro 1), é superior aos resultados descritos por Melo et al (2003), em estudo realizado no estado do Ceará e por Köse et al (2007), na Turquia, que descreveram médias de 469 e de 868 OPG, respectivamente; e inferior aos resultados de Mwamachi et al (1995), no Kênia e Soccol et al (1996), no estado do Paraná, Brasil, com médias de 3.197 e 2.237, respectivamente. No rebanho identificado como Porto Murtinho (Faz.2), o teste de redução não foi realizado, em virtude da baixa contagem de OPG; esta situação foi atribuída ao tipo de manejo empregado, que consistia no pastejo consorciado com bovinos.…”

“…Com relação à molécula Ivermectina, não diferem do descrito por Soccol et al (1996), Molento (2004) e Rosalinski-Moraes et al (2007). Outros estudos revelam índices de resistência mais baixos (Melo et al 2003, Álvarez-Sánchez et al 2006, Traversa et al 2007, Köse et al 2007); mas considerando a situação desse fenômeno no mundo, é possível dizer que existe tendên-cia de aumento nos níveis de resistência pela persistên-cia do uso desta base, em virtude da cultura dos criadores em atribuir a ela alta eficiência facilitada pela redução do preço dessa formulação. A formulação contendo Closantel apresentou alto ín-dice de resistência anti-helmíntica nos rebanhos testados, semelhante ao descrito por Soccol et al (1996) e Chandrawathani et al (1999).…”

Target selected treatment with levamisole to control the development of anthelmintic resistance in a sheep flock

“…Due to the large amount of data related to the development of resistance, there are some controversial recommendations regarding the use of drugs to control helminths. While some authors recommend rotation of anthelmintics within a year or after each treatment (Köse et al 2007;Dobson et al 2011), others suggest rotating them slowly or annually (reviewed by Van Wyk 2001 andby Leathwick 2013) or using an anthelmintic until it is no longer effective (Le Jambre et al 1977;Fleming et al 2006). Studies reveal that all three strategies are being adopted by farmers (Rojo-Vázquez and Hosking 2013), making it necessary to validate those recommendations in the field to assure they are efficient both to control gastrointestinal nematodes and to delay the development of anthelmintic resistance.…”

Examination of Some Endoparasites Prevalence in Romanov Sheep Imported from Ukraine

“…The oral use of these drugs decreases the D. dendriticum load by more than 90% (Akkaya et al, 2006;Onar, 1990;Otranto and Traversa, 2002). Benzimidazoles are frequently used against gastrointestinal nematodes (Köse et al, 2007). Some antiparasitic drugs used following the importation of animals are also effective against D. dendriticum and Nematodirus spp.…”