Anthelmintic Drug Resistance of Gastrointestinal Nematodes of Naturally Infected Goats in Haramaya, Ethiopia

Abstract

Gastrointestinal parasites and their anthelmintic resistance are major constraints to goat production in Ethiopia. Experimental investigation by faecal egg count reduction test (FECRT) and larval cultures were used to assess the occurrence of anthelmintic resistance in naturally infected goats with gastrointestinal nematodes (GIN) in Haramaya, Ethiopia. One hundred goats with a minimum of 150 eggs per gram (EPG) count were selected and randomly divided into five groups, 20 goats in each group, four treated and one untreated group. The result of the faecal egg count reduction test percentage (FECRT%) and the lower 95% confidence limit showed the presence of anthelmintic resistance for all tested drugs except tetramisole. FECRT% and lower 95% confidence limit were 69.9% and 36.9 for albendazole, 84.3% and 66.1 for tetraclozan, 95.7% and 87.4 for tetramisole, and 71.1% and 38.2 for ivermectin, respectively. Trichostrongylus, Teladorsagia, and Haemonchus showed anthelmintic resistance for tested drugs. Coproculture from different treatment groups revealed Trichostrongylus (69.2% in ivermectin and 59.6% in albendazole) were the predominant nematode followed by Teladorsagia (21.9% in albendazole and 14.7% in ivermectin). In tetraclozan treatment group, Trichostrongylus (42%) and Teladorsagia (41.3%) were comparable, followed by Haemonchus (13%). In group treated with tetramisole, Teladorsagia (54.3%) were the most frequently detected nematode followed by Trichostrongylus (25.7%) and Haemonchus (11.4%). Therefore, this study demonstrated the presence of multidrug resistant nematodes that may limit the productivity of goats. Moreover, further studies covering wider areas of Ethiopia and mechanisms of nematode resistance need to be studied in the future.

Anthelmintic Resistance of Gastrointestinal Nematodes of Communally-Grazing Goats in Humbo District, Southern Ethiopia

“…The findings in this study were also in line with those of previous authors, who reported tetramisole as an efficacious drug against gastrointestinal nematodes. 28 , 38 However, the result obtained in this study contrasts with a recent study conducted by Wondimu and Bayu, 17 who reported low efficacy of tetramisole in goats in Ethiopia, with a 95.7% FECR and a 87.4% lower limit of the 95% confidence interval. The finding is also in contrast with the findings of Sissay et al 33 and Regassa et al 35…”

“…from pretreatment coprocultures is consistent with previous reports from other Ethiopian-based studies and other parts of the world. 17 , 27 , 39 Likewise, post-treatment fecal cultures further emphasize the predominance of Haemonchus spp., followed by Trichostrongylus spp., and Strongyloides, suggesting AR against single or multiple anthelmintics for these parasites. Haemonchus and Trichostrongylus species have been identified as resistant parasites in sheep and goats, primarily in tropical and subtropical areas.…”

“… 3 , 5 , 12–16 Similarly, a recent study at a goat farm in Haramaya in Eastern Ethiopia also reported the presence of multidrug-resistant gastrointestinal nematodes against commonly used anthelmintics. 17 …”

First evaluation and detection of ivermectin resistance in gastrointestinal nematodes of sheep and goats in South Darfur, Sudan

“…Also, ivermectin resistance has been identified as problematic for small ruminant farming in Australia [41] and parts of Asia, including China [53], Malaysia [54] and Pakistan [55]. Noteworthy, pasture contamination with nematodes resistant to ivermectin has dramatically increased in Africa as many reports documented the development of resistance in the last decade, particularly for subsistence farming systems, including Ethiopia [13], Nigeria [15] and Uganda [16]. This might be considered as unexpected since subsistence farming would be expected to be associated with low treatment frequency and thus low selection pressure.…”

The identification of small molecule inhibitors with anthelmintic activities that target conserved proteins among ruminant gastrointestinal nematodes

“…Gastrointestinal nematode (GIN) infections are one of the major problems facing livestock producers worldwide, and there is growing concern about the increase in drug resistance to all major classes of anthelmintics ( 1 , 2 ). Once controlled predominantly by anthelmintics, overuse and abuse have led to resistance against most major classes of drugs ( 3 – 7 ). Meat and milk producers have resorted to less than adequate management-based control strategies, especially for those parasites that are the most pathogenic, i.e., Haemonchus spp., Ostertagia ostertagi, and Teladorsagia circumcincta .…”