Resistance of bovine gastrointestinal nematodes to four classes of anthelmintics in the semiarid region of Paraíba state, Brazil

Abstract

The effectiveness of four anthelmintic classes on cattle gastrointestinal nematodes in the semi-arid region of Paraiba State, Brazil, was evaluated. Twenty farms were used, testing 40 animals in each one, totaling 800 animals. Cattle were divided into four groups composed with ten animals: I, treated with albendazole sulfoxide 15%; II, treated with ivermectin 1%; III, treated with closantel 25%; IV, treated with levamisole hydrochloride 7.5%. All treatments were administered subcutaneously. For the Fecal Egg Count Reduction Test (FECRT), individual fecal samples were collected on days 0 and 14, and sent for analysis of egg count per gram of feces (EPG) and larval cultures. It was observed that multiresistance was present in 95% (19/20) of the farms. Resistance to ivermectin and albendazole was observed in 95% (19/20), to closantel in 75% (15/20) and to levamisole in 20% (4/20). The most used management system was semi-intensive (75%; 15/20) and the ivermectin was the most reported drug for controlling helminths (65%; 13/20). Haemonchus spp. was the most prevalent helminth genus. It was concluded that the anthelmintic resistance of bovine gastrointestinal nematodes is high in the semi-arid of Paraíba State, Brazil, with multiresistance observed mainly to ivermectin, albendazole and closantel.

Epidemiological survey of gastrointestinal infections by gastrointestinal nematodes and coccidia in cattle in the semiarid region of Northeastern Brazil

“…Limited knowledge among farmers regarding management practices and animal health contribute to higher levels of nematode and coccidian infections in cattle (Melo et al, 2021). Controlling these infections through good management practices can increase the profit margin of livestock activity in the semiarid region of Paraíba, Brazil.…”

“…Among nematode helminths, the most important and prevalent genera worldwide are those belonging to the superfamily Trichostrongyloidea, especially in tropical areas with a semiarid climate (Almeida et al, 2020). These helminths cause parasitic gastroenteritis in cattle (Micheloud et al, 2015;Henriques et al, 2021;Melo et al, 2021). Among enteric coccidia, Eimeria genera stands out because of its cosmopolitan distribution and parasitism in cattle worldwide, causing high levels of cases of coccidiosis, which can affect up to 100% of young cattle, especially during the first weeks of life (Faber et al, 2002;Gunathilaka et al, 2018;Hamid et al, 2019;Melo et al, 2022).…”

“…Resistant parasite populations hinder effective control in herds. Recently, anthelmintic multidrug resistance was described in cattle herds in the semi-arid region of northeastern Brazil (Melo et al, 2021) and several species of Eimeria parasitizing these animals were later identified (Melo et al, 2022). In such situations, the animals develop clinical symptoms of greater severity, and high mortality rates may occur, thus raising the economic losses (Almeida et al, 2020;Melo et al, 2021).…”

“…Recently, anthelmintic multidrug resistance was described in cattle herds in the semi-arid region of northeastern Brazil (Melo et al, 2021) and several species of Eimeria parasitizing these animals were later identified (Melo et al, 2022). In such situations, the animals develop clinical symptoms of greater severity, and high mortality rates may occur, thus raising the economic losses (Almeida et al, 2020;Melo et al, 2021). It is known that gastrointestinal nematode infections generate an annual economic impact of 7.11 billion dollars worldwide (Grisi et al, 2014).…”