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Iraqi Journal of Veterinary Sciences, Vol. 22, No. 1, 2008 (5-7) Evaluation the effect of albendazole against nematodes in sheep
in Mosul, Iraq
E. K. Mohamed and M. I. Al-Farwachi
Department of Internal and Preventive Medicine, College of Veterinary Medicine, University of Mosul, Mosul, Iraq (Received February 11, 2008; Accepted June 26, 2008) Abstract

Six sheep farms in Mosul city, Iraq randomly selected, were surveyed for gastrointestinal nematodes resistant to Albendazole. On each of 6 sheep farms, 20 lambs were randomly distributed into two equal groups untreated control group, and albendazole (benzimidazole) group (10 mg/kg BW). Faecal egg counts and larval cultures were done at 7, 14, and 21 days after anthelmintic treatment. Resistance was apparent for albendazole on 4 farms out of 6 (66.7%). Post-treatment larval cultures indicated: Strongyloides papillosus, Marshalligia marshalli, Nematodirus spathiger and Haemonchus contortus. Keywords: Albandazole; Nematodes; Sheep
Strongyloides papillosus Marshalligia marshalli Nematodirus spathiger Haemonchus contortus. Introduction
first recognized by a clinical failure in response to anthelmintic therapy and by the persistence of positive Parasitism, and gastrointestinal nematode parasitism in faecal egg counts, or the presence of worms following particular, is arguably the most serious constraint affecting treatment (3). Resistance to anthelmintics in a range of small ruminant production worldwide. Eco-nomic losses are sheep gastrointestinal helminths has been reported from caused by decreased production, cost of prevention, cost of several countries (4). Resistance has been reported most treatment, and the death of infected animals (1). frequently in Haemonchus contortus and it can involve Intensification of animal production has led to an increasing benzimida-zole, salicynilides, levamizole, morantel and reliance on effective anthelmintic drugs to control helminth ivermectin. In Europe, resistance in sheep nematodes has diseases. Regular suppressive dosing of susceptible animals been reported from several countries including France (5). has been shown to result in the development of resistance in Ivermectin resistant Haemonchus contortus in Louisiana sheep nematodes (1,2). Resistance to anthelmintic is usually lambs in U.S.A. (6), and benzimidazole resistant to Iraqi Journal of Veterinary Sciences, Vol. 22, No. 1, 2008 (5-7) stronglyes of sheep in Nigeria (7) have been reported. In 95%. Furthermore, in the above mentioned farm, the lower Iraq, there are few reports of anthelmintic resistance in limit of the 95% confidence intervals was 43.0 suggesting gastrointestinal nematodes of small ruminants. The current that virtually in all the farms, albendazole resistance study was designed to examine resistance of nematodes to nematodes occurred. (Anthelmintic resistance is suspected albendazole in a sample of randomly selected sheep farms when there is less than 80% reduction in nematodes egg output following therapeutic dosage with anthlemintics). By the criteria described, resistance was apparent for Materials and Methods
albendazole on 4 farms out of 6 (66.7%). Post-treatment indicated: Strongyloides papillosus, Six sheep farms located in Mosul city (Iraq) were Marshalligia marshalli, Nematodirus spathiger and randomly selected for this study. Most of the sheep Haemonchus contortus. The Strongyloides papillosus was originated from the northern part of Mosul city. No history the pre-dominant larval type in 3 farms, where as of anthelmintic usage and other management procedures Haemonchus contortus was the dominant genus in one farm The general procedure to detect anthelmintic resistance in nematodes was that recommended by the World Table 1: Number (mean ± SE) for fecal egg count (egg per Association for the Advancement of the Veterinary gram), percentage of fecal egg count reduction Parasitology (WAAVP) (8). None the tested animals had (FECR) after treatment with albendazole (10 received any anthelmintic treatment for at least 6 weeks prior to the start of the study. ON each of the six sheep farms, 20 lambs from both sexes, 2 to 6 months old, were selected, individually identified, and randomly distributed into 2 equal groups. The untreated control group and Albendazole group (Albendazole 2.5% suspension, Al- Salam Factory for drug production, Baghdad, Iraq) given Seven, 14 and 21 days after anthelmintic treatment, Significantly different from day 0 value at p < 0.05. individual faecal samples were taken once from all the animals and processed for faecal egg counting by a modified McMaster technique in which one counted egg Table 2: Post treatment larval cultures (in %) in sheep equated to 50 eggs per gram of faeces (epg) (9). The mean faecal egg count for each treatment group (epg t) was caculated and compared with that of control group (epg c). The faecal egg count reduction (FECR) was determined using the formula (8): According to WAAVP recommendations (8,10) resistance 1- The percentage reduction in egg count is less than 95% 2- The lower limit of the 95 % confidence intervals is less On farms where anthelmintic resistance was detected, a group larval culture was performed to assess the percentage of nematode genera Strongyloides papillosus, Marshalligia marshalli, Nematodirus spathiger and Haemonchus Discussion
contortus by counting at least 100 third-stage larva (L3). The results of this study indicate that low levels of albendazole are effective against nematdes of sheep in the 4 farms out of 6 sheep farms examined. Anthelmintic The mean faecal egg count (FEC) and FEC reduction resistance is suspected in these farms. However, (FECRs) in Table 1. The mean reduction in egg counts after benzimidazole resistance has been described earlier in treatment with albendazole ranged from 21.0 to 72.3%, and sheep farms in the many countries (11-13). The control of all farms except farms 2 and 4 showed values lower than nematode parasites traditionally relies on grazing Iraqi Journal of Veterinary Sciences, Vol. 22, No. 1, 2008 (5-7) management, anthelmintic treatment, or both. However, 6. Miller J, Barras SR. Ivermectin resistant Haemonchus contortus in grazing management schemes are often impractical due to Louisiana lambs. Vet Parasitol 1994; 455: 343-346. 7. Mbah AH, Ogunrinade AF, Dina OA. Benzimidazole resistance in expense or to the hardiness of infective larvae on pasture. In Haemonchus contortus of sheep in Ibadan, Nigeria. African Livestock addition, the evolution of anthelmintic resistance in nematode populations threatens the success of drug 8. Coles GC, Bauer C, Borgsteede FH M, Geerts S, Klei TR, Taylor M, treatment programs (1). Benzimidazole were thought to Waller PJ. World association for the advancement of Veterinary Parasitology (WAAVP) methods for the detection of anthelmintic bind to parasite tubulin and the loss of this binding in resistance in nematodes of veterinary importance. Vet Parasitol 1992; benzimidazole resistant isolates of sheep parasites toge-ther with alterations in the β tubulin isotype distribution in these 9. Coles EH. Veterinary clinical pathology. 4th ed. WB Saunders Co. compared with susceptible worms were decisive in Philadelphia, London: Toronto 1986: 10-75. 10. Kumsa B, Wossenes A. Efficacy of albendazole and tetramidazole confirming the mechanism of action of the benzi-midazole anthelmintics against H. contortus in experiment-tally infected lambs. drugs as well as their mechanism of resistance (14). There Intern J Appl Res Vet Med 2006; 4: 216-221. are two main reasons for the very high prevalence of 11. Mortensen LL, Williamson LH, Terrill TH. Evaluation of prevalence albendazole resistance in sheep nematodes in this survey. and clinical implications of anthelmintic resistance in gastrointestinal nematodes of goats. J Am Vet Med Assoc 2003; 23: 495-500. First albendazole drugs were used very frequently (> 5 12. Abbott KA, Taylor M, Stubbings LA. Sustaible control of parasite in annual treatments) when compared with control practices in sheep. Annual meeting for Vet Surgeons and Advisers 2004. neighbouring Germany with only 2 or 3 treatments per year 13. Fleming ShA, Craig T, Kaplan RM, Miller JE, Navarre Ch, Rings M. (15), secondly albendazole compounds were by far the most Anthelmintic resistance of gastrointestinal parasite in small ruminants. J Vet Intern Med 2006; 20: 435-44. frequently used anthelmintic due to, it is a very cheap than 14. Lacey E. Role of cytokeletal protein, tubulin in the mode of action and other anthel-mintic families. The repeated and exclusive mechanism of drug resistance to benzimidazole. Int J Parasite 1988; use of albendazole products obviously led to the development of resistant nematode strains (16,17) where as 15. Bauer C, Failing K. Einsatz von Anthelmintika zur matoden- bekampfung bei Schafen in Westdeutschland: ergebnisse einer the impact of a continuous suboptimal dosage is more Umfrage. [Use of anthelmintic to control nematode in sheep in West controversial (12,18). Post-treatment larval cultures indicated Strongyloides papillosus was the predominant larval type in 3 farms, where as Haemonchus contortus was 16. Sykes AR, Mcfarlane RG, Familton AS. Parasites immunity and anthelmintic resistance in progress in sheep and goats research. UK: the dominant genus in one farm. Albendazole resistance CAB International, Wallingford 1992: 179-191. was mostly multispecific i.e developing on one farm in 17. Margo H. Manging internal parasite in sheep and goats. NCAT several species of nematodes with the resistant nematode genera involved being Teladorsagia, Trichostrongylus, 18. Borgsteede FHM, Roos MH, Smith G, Prichard K. Workshop summary: anthelmintic resistance. Vet Parasitol 1996; 64: 129-132. Haemonchus, Cooperia. In other European countries 19. Vercruysse J, Dorny P, Meurens K. Benzimidazole resistance benzimidazole resistance in sheep was more often related to nematodes in sheep in Belgium. Vet Rec 1989; 125: 602-603. Teladorsagia circumcincta in Great-Britain (8).
Acknowledgments

This study represents a portion of a diploma report submitted by the first author to the University of Mosul.
The study was supported by the College of Veterinary
Medicine, University of Mosul, Iraq.
References
1. Radostits OM, Gay CC, Blood DC, Hinchlff KW. Veterinary
Medicine: A textbook of the Diseases of Cattle, Sheep, Pigs, Goats and Horses. 10th ed. Philadelphia: WB Saunders Com 2007. 2. Coles GC, Bauer C, Borgsteede FHM, Geerts S. Recommendations for the control of anthelmintic resistance nematodes of farm animals in the EU. Vet Rec 1994; 134: 205–206. 3. Rang HP, Dale MM, Ritter JM, Moore P. Pharmacology. 5th ed. 4. Waller PJ. Anthelmintic resistance and the future for roundworm 5. Waller PJ. Control strategies to prevent resistance. Vet Parasitol 1993;

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