Anthelmintic resistance status of goat gastrointestinal nematodes in Sing Buri Province, Thailand

Abstract

Background and Aim: Promotions of goat farming by both public and private sectors encouraged considerable goat raising in central Thailand. Gastrointestinal nematodes (GIN) infection is a major health and economic problem; however, evidence of resistance to broad-spectrum anthelmintics is frequently reported. Investigation of anthelmintic resistance (AR) status and identification of factors related to the development of AR is important components for sustainable GIN control. However, no information is available on this topic in the study area. The present study aimed to gather information on GIN control practices and to evaluate the effectiveness of albendazole, ivermectin, and levamisole for treating GIN infestation in goat herds in Sing Buri Province. Materials and Methods: Twenty-nine herds were randomly selected. Information on management practices was collected by face-to-face interview using a structured questionnaire. Three field experiments for routinely used anthelmintics, including albendazole, ivermectin, and levamisole were conducted from June 2019 to November 2019. Fecal samples were collected pre- and post-treatment and examined for fecal egg count reduction to determine the status of anthelmintic resistance of goat GIN. Results: Several improper practices were identified that lead to AR, especially chronic use of albendazole and ivermectin. All herds were considered resistant to albendazole and ivermectin, and levamisole resistant nematodes were detected in two herds. AR was strongly linked with the continuous use of anthelmintics. Conclusion: Levamisole, which was still effective in the province, should be used with caution to minimize the selection of resistant strains. Farmers should be provided with updated information for sustainable parasite control. Further, the efficacy of anthelmintics should be routinely monitored.

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

“… 28 Nevertheless, our finding is not consistent with other reports of a 100% reduction in egg count in goats in different parts of Ethiopia 32 , 35 and elsewhere in Europe. 36 On the other hand, Ratanapob et al, 11 Gelot et al, 31 and Eysker et al 37 reported the presence of ivermectin resistance against the nematode population in goats in Thailand, India, and the Netherlands. The suspected resistance of ivermectin might be attributed to the frequent use of this drug by professionals when controlling gastrointestinal helminths in ruminants because of their broad spectrum and endectocide activity; this encourages excessive use and may lead to lower efficacy over time.…”

“… 3 , 12 , 41 It also showed that farmers in the study area perform several practices that may be responsible for promoting the development of AR, which is in line with previous studies conducted in different parts of the world. 6 , 11 , 32 …”

“…Criteria for inclusion included the following: the goat that had not received any anthelmintic in the previous 8 weeks, farmers’ willingness to participate, history of anthelmintic usage, and a fecal egg count (FEC) of ≥150 eggs per gram of feces. 11 , 19 …”

“… 10 Investigation of AR status and identification of factors related to the development of AR are warranted as they are important components of sustainable GIN control. 11 …”

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 .…”