Resistance of Haemonchus, Cooperia, Trichostrongylus, and Oesophagostomum to ivermectin in dairy cattle in Paraná

Abstract

The objective of this study was to analyze the effect of ivermectin (3.15%) on gastrointestinal nematodes found in calves through the fecal egg count reduction test (FECRT), and larval culture in 16 animals from a school farm at the Universidade Estadual do Norte do Paraná. The animals were divided into two experimental groups: animals treated with ivermectin 3.15% (G1 group) and control animals (G2 group). Stool samples were collected from the animals twice i.e., on days 0 and 10 for fecal examinations. There was no significant change in the egg count per gram of feces (EPG) in both the groups. Helminths were found to be resistant to ivermectin (3.15%), due to the observed 5.62% FECRT rate. Cooperia was found to be the dominant nematode larvae present (53% on day 10 day and 8% in day 0), while Trichostrongylus was detected in small numbers (0% on day 0 to 1 % on day 10). The drug was found to be effective only in Trichuris, while the same was inefficient against Haemonchus and Cooperia, although Trichostrongylus and Oesophagostomum were found to be 100 % resistant. Therefore, the findings of this study suggest that ivermectin 3.15% should not be used for the control of nematodes in calves, since most of the parasites demonstrated drug resistance. This is the first report on the resistance of Haemonchus, Cooperia, Trichostrongylus, and Oesophagostomum in cattle to ivermectin 3.15% in the state of Paraná. Key words: Anthelmintic resistance, bovine, macrocyclic lactone ResumoObjetivou-se, neste estudo, analisar o efeito da ivermectina (3,15%) sobre nematódeos gastrointestinais de bezerros com aptidão leiteira por meio do Teste de Redução na Contagem de Ovos nas Fezes (RCOF) e da cultura de larvas em 16 animais da Fazenda Escola da Universidade Estadual do Norte do Paraná. Para tanto, dois grupos experimentais foram formados: animais tratados com ivermectina 3,15% (grupo G1) e grupo controle (Grupo G2). Foram coletadas amostras de fezes dos animais em dois momentos, ou seja, nos dias 0 e 10 para realização dos exames coproparasitológicos. Não houve alteração significativa na contagem de ovos nas fezes (OPG) em ambos os grupos. Os helmintos foram considerados resistentes à ivermectina 3,15%, já que a taxa de RCOF foi de 5,62%. O gênero de nematódeo mais observado na cultura de larvas foi Cooperia (53% no dia 10 a 88% no dia zero) e o menos foi Trichostrongylus (0% no dia zero a 1% no dia 10). Observou-se eficiência apenas sobre o gênero Trichuris e ineficiência sobre os gêneros Haemonchus e Cooperia e ainda 100% de resistência dos gêneros Oesophagostomum e Trichostrongylus. Concluiu-se neste estudo que a ivermectina 3,15% não deve ser indicada no controle de

Cryptosporidium occurrence in ruminants from the North Pioneer mesoregion of Paraná, Brazil

“…Epidemiological studies of parasitic diseases in the North Pioneer mesoregion are scarce. However, the few studies on ruminants in this region have shown high parasite loads, which may reflect poor sanitary conditions and inadequate handling of these animals (HOLSBACK et al, 2013(HOLSBACK et al, , 2015(HOLSBACK et al, , 2016.…”

Diagnóstico e controle químico das helmintoses em bovinos: revisão de literatura

“…Quando adultos, medem até 3 cm e são identificados rapidamente devido sua especificidade de local. As espécies que afetam os bovinos são: Haemonchus placei e Haemonchus similis (Holsback, 2015).…”

“…São encontrados mundialmente, principalmente nos subtrópicos e causam gastrite parasitária. As Research, Society and Development, v. 9, n. 11, e4089119908, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i11.9908 8 espécies que afetam os bovinos são Trichostrogylus axei e Trichostrogylus colubriformis (Urquhart et al, 1996;Holsback, 2015).…”

Gastrointestinal nematode infections do not hinder the development of Simmental X Nellore crossbred calves raised with a nutritionally enhanced diet

“…The use of these endectocides has become customary in the last few decades, and macrocyclic lactones, particularly ivermectin, are among the most widely sold drugs for the control of cattle parasites (Delgado et al, 2009;Neves et al, 2014). However, the continuous use of ivermectin has resulted in anthelmintic resistance, a widespread problem reported in the states of Minas Gerais (Rangel et al, 2005), Rio de Janeiro (Cardoso et al, 2008), Santa Catarina (Souza et al, 2008), Mato Grosso do Sul (Borges et al, 2013), São Paulo (Neves et al, 2014), Paraná (Holsback et al, 2015) and Rio Grande do Sul (Ramos et al, 2016).…”