Abstract: The efficacy of two broad spectrum antelmentics (Ricobendazole and Ivermectin) against gastrointestinal nematode infection was compared in sheep. Naturally infected thirty sheep with Trichostrongylidae sp., which were diagnosed by McMaster technique and their coprocultures were performed. Sheep were randomly assigned to two treatment groups (Ricobendazole and Ivermectin) and one control group of 10. Fecal samples for determining nematode egg counts were collected pre- and post-treatment. All treatments resulted in decrease in the number of Eggs per Gram (EPG) in the post-treatment samples compared to the pre-treatment samples. Mean egg counts reduced 100% for both ricobendazole and ivermectin on trial 14 days. Furthermore, no significant differences were found among treatment groups. The data demonstrate a similar efficacy obtained from both ricobendazole and ivermectin. They were effective and convenient to apply. Either ricobendazole or ivermectin believed to be suggestible to treat gastrointestinal nematodes in sheep.

INTRODUCTION

Gastrointestinal nematod infections in domestic animals cause reduction in meat, milk, wool and pregnancy rate. They can also cause death (Soulsby, 1986). There are several anthelmentic drugs used against these parasites. Ivermectin (Gogolewski et al., 1995), moxidectin (Ayaz and Sahin, 2003), Doramectin (Dorchies et al., 2001), oxfendazol (Yildirim et al., 2008), levamisole (Mohammed et al., 2007), selamectin (Wang et al., 2008) and ricobendazole are all being used for this purpose.

Benzimidazole and probenzimidazole antelmintics are widely used in veterinary and human antelmintic therapy (Cristofol et al., 2001). Ricobendazole, benzimidazole carbamate derivates, which called albendazole sulfoxid is a wide spectrum anthelmentic. This drug inhibits polimerisation of β-Tubulin of parasites, therefore damages energy methabolism of them so, kill the parasites (Formentini et al., 2005). This drug have been used at 3.75 mg kg^-1 dose subcutanously against gastrointestinal parasites (Formentini et al., 2001). After SC injection, ricobendazol is widely distributed from blood to other tissues, especially to the gastrointestinal tract (Lonusse et al., 1998).

Ivermectin is the 22.23-dihydro derivate of avermectin B1, a macrocyclic lactone produced by an actinomycete, Streptomyces avermitilis. It is active at extremely low dosage against a wide variety of nematode and arthropod parasites, apparently by virtue of its action on the mediation of neurotransmission by gamma-aminobutyric acid (Campbell et al., 1983).

Therefore, in the present study, anthelmentic efficacy of ivermectin at 0.2 mg kg^-1 dose and ricobendazole at 3.75 mg kg^-1 dose on the sheep naturally infected with Ostertagia, Haemonchus, Nematodirus and Mashallagia genus parasites were investigated in the region of Van.

MATERIALS AND METHODS

In the present study, 30 sheep kept at the University of Yuzuncu Yil farm, aged between 2-5 years old and weighing 30-50 kg body weight were used. After recording ear numbers; faeces samples were taken from each animal’s rectum. At the same day, faeces samples examined for the presence of parasite eggs using McMaster flotation technique at saturated Zinc sulphate solution (Ministry of Agriculture, Fisheries and Food, 1986). Then coprocultures of the faeces sample were prepared and larval diagnoses were made according to their morphological characters described at the literature (Ministry of Agriculture, Fisheries and Food, 1986). Arithmetic means of the determined eggs were taken.

Infected 30 sheep were divided into 3 equal groups as A, B and C. Sheep in group A received ivermectin (Mectiver inj. Vetas, Turkey) at 0.2 mg kg^-1 dose, sheep in group B received ricobendazole (Rizal inj. Sanovel, Turkey) at 3.75 mg kg^-1 dose. Sheep in group C did not receive any treatment and used as control group.

Faeces samples were collected 7 days before drug application, on the day of the drug application and 7 and 14 days after drugs application for coprologic analysis. During the study the animals used in this study were kept indoor and dry hay and commercial concentrated feed given to the animals.

RESULTS AND DISCUSSION

Seven days before treatment, the day of the treatment and 7 and 14 day after treatment, coprological analysis results with concern to Trichostrongylidae sp. in naturally infected sheep are given in Table 1.

Before treatment, in the coprocultures, Ostertagia sp., Haemonchus sp., Nematodirus sp. and Mashallagia sp. larvae of genus Trichostrongylidae family were diagnosed.

Fourteen days after treatment, no parasite eggs in their faeces were observed in the group A and B. It was determined that both drugs used against Trichostrongylidae family had 100% effectiveness. On the other hand, parasite eggs in the control group were observed during whole sampling periods.

Trichostrongylosis is an important parasite infestation, which cause important economical loses and death (Soulsby, 1986; Umur, 1997). In the country, several researchers investigated Trichostrongyloidae family in sheep and in this family; Ostertagia sp., Haemonchus sp., Nematodirus sp., Cooperia sp., Strongyloides papillosus, Bunostomum sp. and Oesophagostomum sp. subdivisions have been diagnosed widespreadingly (Altas et al., 2006; Guclu et al., 1996; Koroglu et al., 2001; Umur, 1997). In the present study, as mentioned above; Ostertagia sp., Haemonchus sp., Nematodirus sp. and Marshallagia subdivision of Trichostrongylidae family were diagnosed in the faeces of the sheep investigated.

Table 1:	The efficacy of ricobendazole and ivermectin on naturally infected sheep with Trichostrongylidae sp.

Parasitic diseases cause important decrease in the productivity of animals, therefore drug developments against these parasites take important place. In addition, animal owners use these drugs casually from time to time, therofore, resistance may develope against these drugs (Leathwick et al., 2001).

Ivermectins have been used against gastrointestinal nematodes. For instance; Nasreen et al. (2007) used orally in sheep and found 93.21% success, Khalid et al. (2004) 89.85% success, Sarkar et al. (2005) 100% in calves, Park et al. (1998) 94.9% success in goat reported to obtained.

Coronado et al. (1997) investigated the effect of ricobendazole against gastrointestinal nematodes in cattle and found 100% success. Furthermore, Munoz et al. (2008) investigated the efficacy of ricobendazole against gastrointestinal nematodes in sheep and found 50-95% success.

CONCLUSION

In the present study, both ivermectine and ricobendazole had 100% success rate 14 days after treatment against gastrointestinal nematodes, which were used subcutaneously. Therefore, both drugs can be used in the challenge against gastrointestinal nematodes in sheep safely and successfully.

ACKNOWLEDGEMENTS

We would like to thank to Serkan Sekmen from Sanovel drug firm and to Erkan Berberodlu from Vetas drug firm for their support to the present study.