Study on effectiveness of Albendazole and Levamisole as anthelminthic drugs in Flocks in Mashhad

Helminths with creation of clinical diseases, some mortality and subclinica l Complications such as weight loss and anaemia caused a sharp drop in livestock production. Therefore, fighting with them especially in the sheep, which are highly dependent on pasture and therefore are susceptible to worm infection have been considered by veterinary organization so long before and drugs such as albendazole and levamisole have been used in abundance in Iran. In present study, in order to determine the effectiveness of two drugs; albendazole and levamisole, three groups comprised of ten sheep in each group had been chosen in five flocks near the city of mashhad, and after making sure of their physical health, in two stages, one just before administration of the drugs and the other ?? days later, faecal samples were taken from all studied sheep. Then, albendazole (?.?mg/kg) and levamisole (?.?mg/kg) were given to the group one and two orally, respectively. No drug was administrated to the group three as the control group. Counting of parasite eggs in faces (EPG) were performed by using Clayton-Lane method and efficacy of anthelminthic drugs were evaluated by egg reduction rate formula. The results showed that average efficacy of albendazole and levamisole were ??% and ??% respectively which should be considered. So, providing proper instruction under consideration by the aim and time of drug administration, type of parasite, infection rate of worms, the appropriate dosage according to animal species in order to prevent or delay the development of resistance is necessary.