Reduced Albendazole Efficacy in Goats Naturally Infected with Strongyle Nematodes in Dagrase Area, South Darfur State, Sudan

Abstract

Introduction: Understanding the extend of benzimidazole resistance is a core step to adopting the correct strategies for control. In Sudan, benzimidazole resistance was recently reported in cattle and goats in South Darfur. This study aimed to collect additional data regarding albendazole efficacy. Methods: In the rainy season, 100 goats, male and female of different age groups, were screened for the presence of gastrointestinal helminth infections in Dagrase, South Darfur State, Sudan. Goats shedding >150 nematode eggs per gram faeces were selected for in vivo trial and grouped into control (n=15) and a treated group (n=70), that were individually received an oral dose of 10 mg/kg body weight albendazole. The in vitro egg hatch test was performed using thiabendazole.  Results: Using Mini-FLOTAC for egg count determination, 95% of the screened goats were infected with gastrointestinal helminths, and all positive animals were shedding eggs of strongyle nematodes with 92% of strongyle larvae representing Haemonchus spp. Strongyles, Strongyloides papillosus and Skrjabinema ovis were the nematode eggs identified under the microscope. Paired and unpaired faecal egg count reduction test calculations detected reductions of 80/81% and 74/73% with samples taken at days 8 and 14 after albendazole treatment, respectively. Albendazole was inconclusive against Strongyloides papillosus. Haemonchus spp. third stage larvae were the only nematode present after treatment based on coprocultures. The ED50 in the egg hatch test was 0.12 µg/ml thiabendazole. There is a reduction in albendazole efficacy in goats in Dagrase, and consequently the development of benzimidazole resistance.